Bandwidth PSRR of LDOs

ZKZ 64717

03-11ISSN: 1863-5598

Electronics in Motion and Conversion March 2011

GvA Leistungselektronik GmbH | Boehringer Straße 10 - 12 | D-68307 Mannheim

Tel +49 (0) 621/7 89 92-0 | www.gva-leistungselektronik.de | [email protected]

ACCELERATING YOUR PROJECTSWelcome to the House of Competence.GvA is your expert in individual problem solutions for all sectors ofpower electronics – state of the art know how and profound experience as an engineering service provider, manufacturer and distributor.

Consulting – Design & Development – Production – Distribution

www.bodospower.com

Viewpoint

Mature Materials . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

News . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6-13

Blue Product of the Month

Patented InTune™ DC-DC Control Technology . . . . . . . . . . . . . . . 14

Guest Editorial

Europe’s Competitiveness is at Stake

By Heinz Kundert, President, SEMI Europe . . . . . . . . . . . . . . . . . . 16

Market

Electronics Industry Digest

By Aubrey Dunford, Europartners . . . . . . . . . . . . . . . . . . . . . . . . . . 18

Market

New Threats to External ac-dc Power Supplies

By Richard Ruiz Jr., Research Analyst, Darnell Group . . . . . . . 20-21

Cover Story

Auxiliary Power Supplies for Medium and High Voltage Applications

By Werner Bresch, Managing Director of GvA Leistungselektronik GmbH, and Dr. Henrik Siebel, Managing Director of Siebel & Scholl GmbH . . . . . . . . . . . . . . . 22-24

IGBTs

Understanding and Comparing IGBT Module Datasheets

By Dr. Arendt Wintrich, Application Manager, Semikron . . . . . . 26-27

MOSFETs

650V Super Junction Device with Rugged Body Diode

By M.-A. Kutschak and W. Jantscher, Infineon Technologies Austria AG and D. Zipprick and A. Ludsteck-Pechloff, Infineon Technologies AG . . . . . . . . 28-30

Motion Control

Controlling DC Brush Motors with H-Bridge Driver ICs

By Günter Richard, Distribution Sales Director, ROHM Semiconductor GmbH . . . . . . . . . . . . . . . . . . . . . . . . . . 32-35

High Power Switch

Silicon Carbide MOSFETs Provide Ultimate Energy

Efficiency and Easy Design In

By Bob Callanan, SiC Power Applications Manager, Cree, Inc. . . . . . . . . . . . . . . .36-38

High Power Switch

The Silicon Carbide JFET in 3 Phase Power Supplies

By Nigel Springett, SemiSouth . . . . . . . . . . . . . . . . . . . . . . . . . 40-41

Power Supply

Wide Bandwidth PSRR of LDOs

By Masashi Nogawa and Kyle L. Van Renterghem, Texas Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44-47

DC/DC Converter

DC-DC Converter Technologies for Electric/Hybrid Electric Vehicles

By Keith Nardone, Director, Business Development and Tom Curatolo, Director, Applications Engineering, Vicor Corporation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48-50

Measurement

Getting the Best Value Smart Meter for Your Money

By Mark England, CEO, Sentec . . . . . . . . . . . . . . . . . . . . . . . . .52-53

New Products . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54-64

desi

gnho

use

DBC COOLER

High thermalconductivity

Excellent for chipon board

Optimized heat spreading

Highly integrated cooler

Outstanding thermal performance

Customized design

DBC SUBSTRATE

curamik electronics GmbHAm Stadtwald 2D-92676 Eschenbach Phone +49 9645 9222 [email protected]

A division of

efficiency solutions by direct bond copper

2 Bodo´s Power Systems® March 2011 www.bodospower.com

TThhee GGaalllleerryy

Bergquist’s new silicone adhesive – Liqui-Bond® SA1800,is made for screening, designed for cooling.

It’s amazing what a single pass of Bergquist’s new Liqui-Bond SA1800can accomplish.The high bond strength of this liquid adhesive allowsyou to eliminate mechanical fasteners and the high thermal conductivi-ty increases the thermal performance of your assembly. Its low viscosityallows it to be stenciled or screened inposition with precise control. Liqui-BondSA1800 delivers an excellent thermalconductivity of 1.8W/m-K. This productis able to achieve a very thin bond linewith high shear strength for a strong,stable structural bond.

Eliminate fasteners with Liqui-Bond® SA1800.

Liqui-Bond SA1800 is an ideal selection for applications such as power sup-plies, motor controls, electronic control modules, audio amplifiers and discretedevices.This product joins our growing family of other high performing RoHScompliant thermal solutions.Today’s rapidly changing electronic market turnsto Bergquist to keep their world’s electronic components running cool.

Contact us to receive your FREE sample.Take a closer look by requestinga FREE Liqui-Bond CDanimation, sample andproduct Informationtoday. Click online orcall us directly to qualify.

New Liqui-Bond® Silicone Adhesive Screen Prints On SuperiorThermalPerformanceTo Simplify Component And Heat Sink Attachment.

FREE Liqui-Bond®Demo CD,Product Information and Sample.

Thermal Products • Membrane Switches • Touch Screens • Electronic Components

European Headquarters - The Netherlands. Tel: EU +31 (0) 35 5380684 . D +49-4101-803-230 . UK +44-1908-263663

Call +31 (0) 35 5380684 or visit www.bergquistcompany.com/screenprint

B E R GQU I S T H I G H - P E R FO RMANC E S I L I CON E L I Q U I D ADH E S I V E S

CureYourThermal IssuesIn A Single Pass.

Liqui-Bond®SA1800 has a low viscosity, making it easy to achievea thin bond line with high shear strength for electronic assemblies.

Bodo´s Power Systems® March 2011 www.bodospower.com

Our semiconductor world has been built

(mostly) on Silicon. A while ago it was Ger-

manium. We are now in a position to see Sil-

icon Carbide (SiC) and Gallium Nitride

(GaN) mature enough to service the needs

of high efficiency systems. Already, SiC

diodes compliment Silicon IGBTs for reduced

switching loss. At one time only functionality

was important but now, with increasing ener-

gy cost and finite resources, high efficiency

is a must to be competitive. Reducing loss-

es in Power Electronic Systems is now a

major design goal.

New switches are available: both SiC junc-

tion field effect transistors (JFETs) and SiC

N-Channel MOSFETS. Last month, my

Green Product of the Month was a Cree SiC

N-Channel MOSFET. This month we have a

Cree article about progress in the practical

application of these SiC MOSFETs. At

SemiSouth, progress continues with SiC

JFETs the details of which you’ll find in an

article about three-phase power supply

applications.

Silicon carbide has the potential for operat-

ing at higher junction temperatures.

Using this feature requires a matching capa-

bility in passive components and in packag-

ing the final application. Beyond the semi-

conductor, an efficient and practical design

requires capacitors, inductors and resistors

with a similar level of life expectancy and

reliability. The challenges related to “Mature

Materials” is the theme for this year’s Podi-

um discussion at the PCIM Europe; Nurem-

berg, Wednesday, May 18th at 12:20.

Join us and hear Industry experts forecast-

ing future designs.

We look forward to all the discussions at

upcoming events. I may see you at the

APEC in a few days in Fort Worth. An enthu-

siastic engineering community will meet to

push forward design elements and research

that make for significant progress. GaN will

be evident, moving ahead into practical

designs.

But never the less, silicon is still a platform

for great switches for today’s designs. We

have an article by Infineon showing the ben-

efits of the latest CoolMOS developments.

And Semikron explains in this issue what to

take into consideration while comparing data

sheets in the power module world of IGBTs.

My Green Power Tip for March:

Trimming trees and bushes is still great

exercise, and using the wood in your fire

place saves a little gas or oil. One little thing

at a time will make a big impact - if we all

do it.

Looking forward to see you next week in

Texas.

Best Regards

Mature Materials!

V I E W P O I N T

4

A MediaKatzbek 17a

D-24235 Laboe, Germany

Phone: +49 4343 42 17 90

Fax: +49 4343 42 17 89

[email protected]

www.bodospower.com

Publishing EditorBodo Arlt, [email protected]

Creative Direction & ProductionRepro Studio Peschke

[email protected]

Free Subscription to qualified readers

Bodo´s Power Systems

is available for the following

subscription charges:

Annual charge (12 issues) is 150 €

world wide

Single issue is 18 €

[email protected]

circulation print run

20000

Printing by:

Central-Druck Trost GmbH & Co

Heusenstamm, Germany

A Media and Bodos Power Systems

assume and hereby disclaim any

liability to any person for any loss or

damage by errors or omissions in the

material contained herein regardless of

whether such errors result from

negligence accident or any other cause

whatsoever.

Events

Embedded World

Nuremberg, Ger. March 1st-3rd

www.embedded-world.eu/

APEC 2011

Ft. Worth, TX, USA March 6th-10th

www.apec-conf.org/

EMC2011,

Stuttgart, Ger. March.15th–17th

www.mesago.de/de/EMV/home.htm

Battery Forum,

Aschaffenburg, Ger

March 23th-24th

www.batteryuniversity.eu

New Energy

Husum Ger. March17th-20th

www.new-energy.de

EXPOELECTRONICA,

Moscow, Russia April 19th-21st

http://expoelectronica.primexpo.com


N E W S

Micrel Inc.

announced the

appointment of

Mansour Izadinia,

a semiconductor

industry veteran,

as the Company's

Senior Vice Presi-

dent of the Analog

Division. Mr. Iza-

dinia will have gen-

eral management and overall responsibility

for Micrel's largest division. He will report to

Mr. Ray Zinn, President, CEO, founder and

Chairman of the Board of the Company.

Mr. Izadinia brings to Micrel more than 26

years of experience in analog and mixed sig-

nal product development and marketing. He

most recently served as Chief Technology

Officer of Integrated Device Technology

(IDT) where he was responsible for IDT's

new product development strategy and

methodologies. He spearheaded IDT's tran-

sition into the analog mixed signal markets

by forming the Analog and Power Manage-

ment Division of IDT. Prior to IDT, Izadinia

served as Vice President at Maxim Integrat-

ed Products where he was the General Man-

ager of one of Maxim's major analog and

power management business units. Prior to

Maxim, he held design engineering and

management positions at National Semicon-

ductor Corporation where he led the devel-

opment of many highly profitable standard

products. Mr. Izadinia holds a Master's

degree in Electrical Engineering from Santa

Clara University and a Bachelor's degree in

Electrical Engineering from UCLA.

"Mansour comes to Micrel with a wealth of

knowledge and experience in product devel-

opment, marketing and operational manage-

ment. Many of us at Micrel have known

Mansour for many years," said Mr. Zinn.

"He is a visionary industry leader and tech-

nologist who has built and run many suc-

cessful and highly profitable business units.

We are very excited to have Mansour on our

executive team. We look forward to his

many contributions and helping us with our

overall SAM expansion program. In addi-

tion, Mansour will be a great asset in com-

municating Micrel's analog strategy with the

investment community, as Micrel reestab-

lishes itself as a leader in the high perform-

ance analog space. The world of analog

has become very competitive and we are

delighted to have a high caliber leader such

as Mr. Izadinia as we deal with this rapidly

changing environment," said Mr. Zinn.

"I am honored and proud to join one of the

finest analog mixed signal companies in our

industry. I am very excited about the great

opportunities ahead of us and I am confident

in our ability to take the company to new

heights. I look forward to working with the

Micrel team," noted Mr. Izadinia.

www.micrel.com

Mansour Izadinia Joins Micrel as Senior Vice President of Analog Division

The 4th Developer Forum Battery Technolo-

gies), hosted by the batteryuniversity.eu,

takes place on March 23 and 24, 2011 in the

"Stadthalle Aschaffenburg", Germany. Atten-

dees are offered more than 30 presentations

by leading experts on current topics such as

the latest battery technologies and chemi-

cals, reliability and lifetime of batteries,

charger technologies, regulations and stan-

dards, United Nations transportation regula-

tions for lithium batteries, battery test equip-

ment, safety of large rechargeable batteries,

protection circuits, battery drive systems and

power management for electric and hybrid

vehicles, fuel cells and a lot more.

During the two days, there is also the oppor-

tunity to gain some practical experience. For

example, a 4 hour seminar is dedicated to

the development of power-saving systems

with Microchip’s nanoWatt XLP microcon-

trollers. In exercises on laptops, attendees

learn more about system design techniques

for a power-saving external circuit, diverse

power-saving modes of on-chip peripherals,

various power profiles and dynamic clock

frequency control.

The main language of the conference is Ger-

man. Only a few presentations will be held in

English.

The detailed program of events and registra-

tion form can be downloaded from the

homepage

www.batteryuniversity.eu

Battery Trends and Technologies at 4th Developer Forum

The Forum for the electronic industry includes:

EXPOELECTRONICA - International Trade Fair for Electronics Manu-

facturing Technology

ELECTRONTECHEXPO - International Trade Fairs for Components,

PCBs and Electronics Production and for Electronics Manufacturing

Technology

LEDTECHEXPO - Exhibition of International Exhibition for LED solu-

tions, chip design and manufacturing

Today, the Russian electronics industry is received increasing atten-

tion from the government. The “Strategy for the development of the

electronics industry up to 2025” and Federal Target Programme

“Development of the electronic component base and radio electronics

for 2008-2015” have been developed and are being implemented,

and clearly identify objectives for the industry. Furthermore, the pro-

gressive development of Russian electronics is supported by the sci-

entific potential of the Russian electronics industry, which has a quite

large domestic market, with high growth and significant development

potential, which explains its attractiveness to foreign companies and

investors.

One of the main events in the Russian electronics industry, which

most fully represents the domestic and global market, is the Interna-

tional Forum of the Electronics Industry. It is the largest exhibition

project in the field of electronics not only in Russia, but throughout

Eastern Europe. The forum is the undisputed leader in showcasing

the latest advances in the electronics industry, and an excellent plat-

form for constructive dialogue between leading experts. A consider-

able role in this is played by the extensive business programme,

which includes scientific and practical conferences, technical semi-

nars, press conferences by leading manufacturers, roundtables and

exhibitor presentations.

From year to year the Forum attracts more and more attention from

highly qualified professionals: in 2010 year 13,520 trade visitors from

58 constituents of the Russian Federation and 39 countries visited

the exhibition. 79% of them are empowered to make decisions about

cooperation and procurement. 94% of participants were satisfied with

the quantity of visitors.

http://expoelectronica.primexpo.com

Crocus Expo Moscow, Russia April 19th to 21st

[ www.infi neon.com/coolmos]

650V CoolMOS™ CFD2Introduction of new market leading 650V CoolMOS™ technology with integrated fast body diode

With the new 650V CoolMOS™ CFD2 Infineon launches its second generation of its market leading high voltage MOSFET´s with integrated fast body diode. This new outstanding product is planned to be the successor of 600V FCD with improved energy efficiency. The softer commutation behavior and therefore better EMI behavior gives this product a clear advantage in comparison with competitor parts.

Key features and benefits of Infineon’s 650V CoolMOS™ CFD2� First 650V technology with integrated fast body diode on the market � Limited voltage overshoot during hard commutation� Significant Qg reduction compared to C3 based CFD technology� Tighter Rdson max to rdson typ window� Easy to design in� Lower price compared to C3 based CFD technology

For further information please visit our website:

8 Bodo´s Power Systems® March 2011 www.bodospower.comBodo´s Power Systems® March 2011 www.bodospower.com

N E W S

Infineon Technologies AG opened a facility in

China called Infineon Integrated Circuits

(Beijing) Co., Ltd., located in the Beijing Eco-

nomic and Technological Development Area.

In addition to sales and marketing, applica-

tion R&D and central functions, the new enti-

ty houses an IGBT stack manufacturing facil-

ity and a technical center for automotive

solutions. IGBTs (Insulated Gate Bipolar

Transistors) are power semiconductors used

to drive electric motors both in automotive

applications and in trains. Motor speed and

torque can be regulated along a gradual

scale. They also play an important role in the

use of renewable energies: here IGBTs

enable the efficient conversion of variable

frequency output such as from a wind tur-

bine or solar plant to a fixed frequency

appropriate for the grid in the region con-

cerned.

"Global energy demand is constantly

increasing, particularly in emerging markets

like China, one of the most important and

fastest growing strategic markets for Infi-

neon," said Peter Bauer, CEO of Infineon

Technologies AG. “Infineon has dedicated

many years to develop state-of-the-art semi-

conductor solutions. This new entity will

enable us to raise our output to meet the

extremely expanding demand especially for

energy efficiency and electromobility solu-

tions in China and brings us closer to our

customers in this region.”

China plans to invest around 700 billion US

dollars until 2020 in renewable energy proj-

ects and expects to expand the high-speed

rail network from today’s 7,500 to 13,000

kilometers by 2012. Infineon is engaged in

many wind and solar power as well as high-

speed train projects in China with its semi-

conductor solutions. According to the gov-

ernment's blueprint, China's railway network

will serve more than 90 percent of the popu-

lation by 2020, with 16,000 kilometers of

new lines. Furthermore, the Chinese govern-

ment intends to make individual mobility

more sustainable, investing in electric and

hybrid cars. From 2020 onwards, one million

hybrid and electric cars are planned to leave

the assembly line in Chinese plants every

year.

The new Infineon entity in Beijing will sup-

port all three Infineon business segments

Automotive, Industrial & Multimarket as well

as Chip Card & Security. Today, Infineon

develops, produces and markets innovative

semiconductor solutions at several locations

in China with around 1.700 employees serv-

ing the energy efficiency, mobility and securi-

ty needs of the global and the Chinese mar-

ket.

Beijing Economic and Technological Devel-

opment Area is a state-level economic and

technological development zone in Beijing,

China. It is located in the Yizhuang district

with convenient transport links and

advanced infrastructure. Key industries in

the zone include electronic products, phar-

maceuticals, information technology,

mechanical engineering and materials

research.

www.infineon.com

Meeting the Growing Demand for Energy Efficiency in China

Fairchild

Semiconduc-

tor has

appointed Dan

Kinzer, chief

technology

officer and

senior vice

president,

Technology.

Under Mr. Kinzer’s leadership, Fairchild will

sharpen its focus on technical innovation to

further advance the company’s advanced

product offerings in power electronic and

mobile applications.

Mr. Kinzer joined Fairchild Semiconductor in

2007 as Senior Vice President of Product

and Technology Development for the compa-

ny’s Power Group. His background includes

decades of experience in leading innovative

semiconductor technology, product and

package development projects. He is an

inventor with over 70 U.S. patents and multi-

ple international patents, has authored

numerous scientific and trade articles,

served as General Chairman of the Interna-

tional Symposium on Power Semiconductor

Devices and Integrated Circuits, and is a

member of IEEE and EDS. He graduated in

Engineering Physics from Princeton Univer-

sity.

“I am very honored by this appointment and

excited to take on this challenge,” stated Mr.

Kinzer. “Fairchild is already a leader in many

of our chosen applications, and it will be my

mission to extend that lead and open up new

opportunities for the company through tech-

nology. We have an extremely talented

team, and I am grateful for the support that

has enabled me to reach this position.”

www.fairchildsemi.com

Dan Kinzer for Chief Technology Officer

Dow Corning has formalized an agreement

to enter the imec multi-partner industrial

R&D program on GaN semiconductor mate-

rials and device technologies. The program

focuses on the development of the next gen-

eration GaN power devices and LEDs. The

collaboration between Dow Corning and

imec will concentrate on bringing the GaN

epi-technology on silicon wafers to a manu-

facturing scale.

Due to the combination of superior electron

mobility, higher breakdown voltage and good

thermal conductivity properties, GaN/AIGaN

heterostructures offer a high switching effi-

ciency for the next generation power and RF

devices compared to the current devices

based on silicon (Si). A process for high

quality GaN epi-layers on Si substrates is

key in obtaining superior power & RF

devices. Accurate control of the epi-growth

process to master substrate bow, epi-layer

defectivity and uniformity while maintaining

high epi-reactor throughput are needed to

reduce the overall technology cost. Imec has

pioneered GaN epi-growth on sapphire, SiC

and Si substrates from 2 to 6 inch substrate

sizes and currently focuses on developing

GaN epi-layers on 8 inch Si substrates.

Leveraging the economics of scale and com-

patibility with high throughput and high

capacity 8 inch Si wafer based process tech-

nology will further reduce the cost of GaN

devices and LEDs.

www.imec.be

Dow Corning Joins the imec GaN Affiliation Program

For electric, hybrid and battery vehicles

MOSFET inverter: up to 55 kVA

Vbattery: 24V - 160V

IGBT inverter: up to 250 kVA

VDC :150V - 850V

IP67 enclosure

SKAITM

Most compact inverter systems: 20 kVA/l

Australia +61 3-85 61 56 00 Brasil +55 11-41 86 95 00 Cesko +420 37 80 51 400 China +852 34 26 33 66 Deutschland +49 911-65 59-0 España +34 9 36 33 58 90 France +33 1-30 86 80 00 India +91 222 76 28 600 Italia +39 06-9 11 42 41 Japan +81 68 95 13 96 Korea +82 32-3 46 28 30 Mexico +52 55-53 00 11 51 Nederland +31 55-5 29 52 95 Österreich +43 1-58 63 65 80 Polska +48 22-6 15 79 84 Russia +7 38 33 55 58 69 Schweiz +41 44-9 14 13 33 Slovensko +421 3 37 97 03 05 Suid-Afrika +27 12-3 45 60 60 Suomi +358 9-7 74 38 80 Sverige +46 8-59 4768 50 Türkiye +90 21 6-688 32 88 United Kingdom +44 19 92-58 46 77 USA +1 603-8 83 81 02 [email protected] www.semikron.com

3-phase IGBT inverter system up to 250 kVA


N E W S

IXYS corporation disclosed its participation

in the HiT Module project in Germany.

Desert and Arctic: Automobile sytems and

airplanes encounter such vast temperature

extremes every day. Hardly noticed, highly

developed components in electrical drives

deliver continuous heavy-duty performance

amidst heat and cold. But the requirements

on electrical components are constantly

growing: Thus, the HiT Module joint project,

sponsored by the Federal Ministry of Educa-

tion and Research (BMBF), focuses on

increasing reliability and energy efficiency of

power electronics components. The partners

IXYS Semiconductor GmbH Lampertheim,

Fraunhofer-Institut für Werkstoffmechanik

IWM Halle, Technische-Universität Chemnitz,

Otto-von-Guericke-Universität Magdeburg as

well as the associated Liebherr-Elektronik

GmbH from Lindau jointly conduct this

research.

The HiT Module's project objective consists

of studying a concept for power electronics

components suitable for the very high ther-

mal stresses in aerospace as well as auto-

motive applications. Power electronics mod-

ules are responsible for the control of electri-

cal drives in these transport vehicles. At this,

they are expected to function reliably for

many years under extreme conditions. The

components must continue to perform under

frequent temperature cycles ranging from

minus 60 °C in aviation to over 150 °C in the

automobile.

Even up to 175 °C and more may occur in

some areas inside the components while in

operation. At the same time the components'

footprint should be as small as possible to

save space and weight.

The research project aims at meeting these

high demands by employing new materials

and innovative assembly technique in the

construction of these parts. One of the core

elements hereby consists of the production

and application of a new substrate structure

from aluminum oxide ceramics with an alu-

minum strip conductor system (Direct Alu-

minum Bonding, DAB).

The new concept to be researched will dras-

tically increase the potential of applying

power electronics systems in the areas of

aircraft and automotive technology. Positive

effects on the energy efficiency of the overall

system will result especially from the

improved reliability of the power electronics

modules as well as the weight reduction. For

example, hydraulic systems can be replaced

by smaller and lighter electromotor systems

in aircrafts or powerful hybrid drives in auto-

mobiles.

www.ixys.com

Power Semiconductor Components for Extreme Conditions

The SENSOR+TEST Conferences are held biannually in the odd

years, traditionally complementing the SENSOR+TEST trade fair at

the Nürnberg Exhibition Centre. Thus, the three international confer-

ences, SENSOR, OPTO, and IRS², will again offer a comprehensive

overview of the state of the art in research and development in the

areas of sensor technology, optical and infrared measurement.

The conferences are again ably chaired by Prof. Dr. R. Lerch (Uni-

versity of Erlangen-Nürnberg) jointly with Prof. Dr. R. Werthschützky

(TU Darmstadt) for the SENSOR Congress, Prof. Dr. E. Wagner

(Fraunhofer Institute IPM, Freiburg) for the OPTO Congress, and

Prof. Dr. G. Gerlach (TU Dresden) for the IRS² Congress. The com-

plete agenda for all three conferences is available on the web. They

are as comprehensive as never before: About 230 (!) papers and

posters are being offered during the three-day sessions.

Prof. Lerch commented: “The scientific conferences at the SEN-

SOR+TEST are well established as a permanent component of the

international measuring technology scene. In times when other

events are suffering from a decreasing number of participants, we

were in fact able to expand our conferences. The SENSOR Confer-

ence, for instance, will have four parallel sessions this year, instead

of three as in the past. The topics range from basic sensor principles

to novel manufacturing methods. The conferences are of interest for

both, sensor developers and users in the area of automation technol-

ogy.”

The SENSOR+TEST Conferences 2011 will start jointly on the first

day of the fair with an opening lecture by Prof. Dr. E. Göbel, Presi-

dent of the National Metrology Institute (Physikalisch-Technischen

Bundesanstalt) in Braunschweig, on the subject of “Fundamental

Constants and the New International System of Units (SI).” Also, the

AMA Association’s 10,000-Euro SENSOR Innovation Award will again

be presented during the opening ceremony.

www.sensor-test.com

SENSOR+TEST 2011 More Comprehensive than Ever

SEMI announced the

appointment of Dirk

Stenkamp, Management

Board member and Chief

Operating Officer of cen-

trotherm photovoltaics

AG, as member of the

SEMI Europe Advisory Board. centrotherm

photovoltaics is a worldwide leading supplier

of key equipment and production lines for

the production of crystalline and thin-film

solar cells.

"This appointment represents both a high

distinction and, at the same time, an incen-

tive for me,” stated Dr. Dirk Stenkamp. "I am

looking forward to contributing my experi-

ence and knowledge from the semiconductor

and photovoltaic equipment sector to the

association's work.

SEMI announced the

appointment of Paul

Hyland, president and

CEO of AIXTRON SE, as

member of the SEMI

Europe Advisory Board.

AIXTRON is a leading

provider of deposition equipment to the

semiconductor industry. The Company's

technology solutions are used by a diverse

range of customers worldwide to build

advanced components for electronic and

opto-electronic applications based on com-

pound, silicon, or organic semiconductor

materials and more recently carbon nanos-

tructures.

"I am delighted to have been asked to join

the SEMI European Advisory Board at a time

when the global challenges and opportuni-

ties within the Technology sector have never

been so important for the European Technol-

ogy industry”, stated Paul Hyland. "Europe

has a long, rich, and often, underappreciat-

ed, history in technology innovation and has

some of the world’s leading players in cut-

ting-edge technology within its borders.

ww.semi.org

Dirk Stenkamp and Paul Hyland Joining SEMI Europe Advisory Board

Semiconductor European Business Groupwww.mitsubishichips.eu · www.mitsubishichips.com

[email protected]

IGBT Modules(NX-Series)

TFT-LCD Modules

. . . for appl icat ionswith highest re l iabi l i ty

N E W S


Argonne National Laboratory has licensed its cathode technology to

Envia Systems, Newark, Calif. The deal marks the fifth licensing

agreement for the Argonne-developed cathode technology.

Building on the existing award-winning Argonne-Envia collaboration,

the Argonne license contributes complementary technology to Envia’s

development of industry-leading Li-Ion battery solutions. General

Motors announced today that it will invest $7 million in Envia to pro-

vide its "battery engineering team with access to advanced lithium-

ion cathode technology that delivers higher cell energy density and

lower cost."

In a separate announcement today, Envia Systems said that its High

Capacity Manganese Rich cathode material for advanced batteries is

available in limited quantities for pilot vehicle programs.

“Today we are once again seeing the benefits for the American peo-

ple that come with federal investments in science and innovation.

With this new agreement, a battery technology, originally developed

at the Department of Energy’s Argonne National Laboratory, is mak-

ing its way into the market. By supporting American innovation, com-

mercialization and manufacturing, this partnership is helping to boost

U.S. competitiveness and create the jobs of the future,” said U.S.

Energy Secretary Steven Chu.

GM, LG Chem, Ltd., BASFand Toda Kogyo have also licensed the

Argonne-developed technology.

www.anl.gov/Media_Center/News

/2011/news110126.html

License for Advanced Battery Technology

Payton Planar designs are used in harsh environments like space,

aircraft, missiles and automotive. Magnetics in general are tested

and qualified per Mil-PRF-27, Transformers and Inductors General

Specifications. In addition, Mil-STD-981 comes into play for Design,

Manufacturing and Quality Standards for Custom Electromagnetic

Devices for Space Applications.

Product quality can be verified through environmental testing such as

vibration, thermal cycling, mechanical shock, thermal shock, HALT

and HASS. The experience and analysis of an advanced engineering

group can minimize or even eliminate any design flaws on a new

design.

Environmental Testing on Planar Magnetics:

The test methods for Electronic and Electrical Component Parts are

per MIL-STD-202. Payton has performed HALT, Highly Accelerated

Life Testing, per MIL-STD-202. Payton Planars have been tested to

200G mechanical shock in all 3 axis, random vibration to 40Grms up

to 8 hours in each plane, moisture resistance at 85C with 85% RH for

1000 hours, thermal shock from -55C to 130C for 100+ cycles, and

altitude from -1,300 to 65,000 feet.

Resistance to solvents, solderability and corona discharge are some

other tests that Payton has successfully performed on our Planar

Magnetics.

Payton also performs HASS, Highly Accelerated Stress Screening.

HASS, an abbreviated form of HALT, is an ongoing screening test

performed on regular production Planar Magnetics. During HASS, we

try not to damage the product but rather to verify that actual produc-

tion units continue to operate as designed when subjected to the

environments used during the HASS test.

www.paytongroup.com

Planar Magnetics Designs for Harsh Environments

Following a 41.6 percent boom in 2010, revenue growth in the global

power management semiconductor market will slow significantly in

2011 but still will manage to increase at a double-digit pace, accord-

ing to new IHS iSuppli research.

Global power management semiconductor revenue will climb to

$36.2 billion in 2011, up 13.9 percent from 2010. Growth will occur

during every quarter throughout 2011, as presented in the attached

figure.

“The solid rise in 2011 follows a banner year in 2010, when power

management semiconductor revenue soared to $31.8 billion,” said

Marijana Vukicevic, principal analyst for power management at IHS.

That figure, Vukicevic noted, was up from $22.5 billion in 2009.

Growth will decelerate in 2011 because this year follows a period of

extraordinary growth in 2010. “Sales in 2011 simply will not be able

to keep pace with the rapid expansion of 2010, when revenue

rebounded dramatically from the recession year of 2009,” Vukicevic

added.

Among the factors causing the continuing expansion of global rev-

enue in 2011 is the move toward more efficient battery-powered

devices. With consumers everywhere looking for longer battery life in

their mobile devices—from cell phones to tablets, to notebooks, to

portable navigation devices—new design trends will likely emerge in

power management integrated circuits (ICs), boosting revenue

among suppliers.

Another factor driving expansion will be the growth in alternate ener-

gy markets, including solar, wind, the electrification of vehicles and

the smart grid. IHS iSuppli research shows alternative energy being

transformed from an emerging market in power management to a

more mainstream segment in 2011, thus generating revenue growth

for suppliers.

www.ihs.com

www.isuppli.com

Battery-Powered Devices and Alternate Energy Markets to

Drive Power Management Growth in 2011

$0,0

$2,0

$4,0

$6,0

$8,0

$10,0

$12,0

Q1

Q2

Q3

Q4

Q1

Q2

Q3

Q4

2010 (estimate) 2011 (forecast)

Global Power Management Semiconductor (Billions of U.S. Dollars)

Source: IHS iSuppli Research

13www.bodospower.com March 2011 Bodo´s Power Systems®

The German Ministry of Education and

Research is backing a research project on

the optimization of passive components with

maximum energy density and the use of

these components in power electronics. The

project involves the partners Bosch, Semi-

kron, Epcos, Sumida, Fraunhofer IISB, Treo-

fan, FIT Ceramics, VIA Elektronik, as well as

the Fraunhofer Institute for Ceramic Tech-

nologies and Systems IKTS.

Leading passive component manufacturers

such as Epcos, Sumida and Via Elektronik

are joining forces with materials specialists

and research institutes such as Treofan, FIT

Ceramics, Bosch, Semikron, Fraunhofer IISB

and Fraunhofer IKTS to work on the joint

research project “Efficient passive compo-

nents with maximum energy density for

increased temperature range in power elec-

tronics – EPa”.

On the basis of the high-tech strategy of the

German government, manifest in the “IT and

communications technology 2020” initiative,

IKT 2020, the German Ministry of Educa-

tion and Research, BMBF, is providing

funding of €1.669 million, the total volume

is totalling €2.923 million, which is being

put into the EPa project as part of the “LES:

Power electronics for energy efficiency

enhancement" programme.

This application-oriented research project is

intended to create a basis for innovations in

the field of passive components – in con-

nection with state-of-the-art power supply

systems. One of the aims of IKT 2020 is to

expand and bolster Germany’s leading posi-

tion in the field of ICT. The project will last

for a period of three years and is expected

to be complete by the end of May 2013.

The aim if the EPa project is to enable the

manufacture of far more compact – and

hence resource-efficient power supply sys-

tems – by using innovative passive compo-

nents. “What makes this cluster different

from others is that for the first time compo-

nent manufacturers and users are working

together on improving the technology used

in switched-mode power supply systems,”

explains the cluster co-ordinator Johann

Winkler from SUMIDA Components &

Modules GmbH.

www.Epcos.comwww.Bosch.com

www.via-electronic.de

www.Treofan.com

www.SUMIDA.com

www.Fraunhofer.com

www.FIT-Ceramics.com

www.semikron.com

Maximum Power Density in Passive Components

Bernhard Kalkmann, technical director at Semikron in Nuremberg

“What makes this clusterdifferent from others is thatfor the first time componentmanufacturers and usersare working together onimproving the technologyused in switched-modepower supply systems,”

explains the cluster co-ordinator Johann Winklerfrom SUMIDA Components& Modules GmbH.

In a move to employ social media to assist

career development for business and engi-

neering professionals, Rogers Corporation

has launched online communities on social

media sites such as such as Facebook, Twit-

ter, LinkedIn and YouTube. On these sites

professionals can participate in conversa-

tions about career opportunities in the manu-

facturing and technology fields; engage in

discussions related to career development

and advancement; grow their own profes-

sional networks, connect with colleagues

and industry leaders, and find mentors.

The social media presences are linked to the

new Rogers Corporation U.S. Careers Cen-

ter page at Rogers’ website (www.roger-

scorp.com/careers/us). Here professionals

can conduct job searches of open positions

at Rogers and apply online. The site also

provides information for prospective student

interns, describes the corporate/community

life at Rogers Corporation, and provides a

link to videos found at the Rogers Corpora-

tion YouTube Channel. Visitors can also

subscribe to a Careers blog to learn about

social networking for professional success.

“Social media is unquestionably a powerful

communication tool that employers, like

Rogers Corporation, need to participate in,”

commented Sue Flanigan, U.S. Director of

Human Resources. “High caliber employ-

ees are critical to our success as a compa-

ny, both as employees and customers, so

we see our presence on these sites as pro-

viding an important resource for career pro-

fessionals, plus a direct link to a possible

career with Rogers Corporation.”

www.rogerscorp.com

Career Opportunities by Social Media Sites

From One Engineer To Another

Andy Mackie PhD, [email protected]

Find out:www.indium.com/12345

scan code with mobile device

answers

blogs

tech papers

one-on-one

support

live chat

ASIA CHINA EUROPE USA ©2011 Indium Corporation

“ Are lead-containing alloys still allowed in applications for semiconductor and power semiconductor assembly?”

Maxim Integrated Products announced its entry into the fast-growing

digital power market with its patented InTune™ brand digital power

technology1 it is based on “state-space” or “model-predictive” control

rather than proportional-integral-derivative (PID) control used by com-

petitors. Maxim’s InTune™ digital power technology performs an

automatic compensation routine that is based on measured parame-

ters, which enables the construction of an internal mathematical

model of the power supply including the external components. The

result is a switching power supply that achieves the highest possible

dynamic performance while guaranteeing stability. Furthermore, this

information enables several proprietary algorithms that optimize effi-

ciency across a wide range of operating conditions. Maxim’s

InTune™ digital power technology requires up to 5x lower bias cur-

rent than competing devices, further improving overall efficiency for

applications such as networking, telecom, and servers.

“Unlike competing technology, Maxim’s InTune™ digital power tech-

nology is not an iterative tuning technique. It is deterministic and

resolves several limitations present in today’s digital power solutions,”

said Jim Templeton, Director of Business Management, leading

Maxim’s digital power effort. “Unlike PID-based solutions, the loop

used by Maxim’s InTune™ digital power technology provides seam-

less small- and large-signal response without the need to cross back

and forth between linear and nonlinear modes. This enables loop

response up to 10x faster than competitors and does not require any

user-set thresholds. In fact, the PWM controllers used by Maxim’s

InTune™ digital power technology are even faster than their analog

equivalents.”

In addition to internal R&D efforts, the Company has made a key

acquisition of a digital power R&D firm and notable university intellec-

tual property. The Company also recently licensed digital power tech-

nology “DPT” patents from Power-One, Inc. Using its new technology

and acquisitions, Maxim plans to leverage its position as a top suppli-

er of power-management and control ICs to become the number one

supplier of digital power solutions.

“Maxim’s InTune™ digital power technology represents the next-gen-

eration of digital power,” said Wei Tang, Director of R&D at Delta

Electronics, Inc. “By providing the best transient response over all

operating conditions and enhanced efficiency modes, Maxim’s

InTune™ digital power technology allows us to enable new features,

flexibility, and enhanced performance for our power supply cus-

tomers.”

Maxim is building a complete family of digital power products to com-

plement its full offering of analog power ICs. The first chips using

Maxim’s InTune™ digital power technology are currently sampling

with partner customers; individual product announcements will follow

in the coming months. Maxim will be demonstrating its InTune™ digi-

tal power technology at the Applied Power Electronics Conference

(APEC) in Fort Worth, Texas, USA in March.

InTune is a trademark of Maxim Integrated Products, Inc.

1U.S. Patents #7,622,820 and #7,586,767.

www.maxim-ic.com

B L U E P R O D U C T O F T H E M O N T H


Patented InTune™ DC-DC Control Technology


The semiconductor industry is a key contrib-

utor to European economic growth and pros-

perity, and an important enabler of Europe’s

success in the communications, automotive,

industrial machinery industries. The semi-

conductor industry provides solutions for the

important issues in our society and serves

as the foundation for progress in energy

conservation, renewable energy, transporta-

tion, biotechnology, medical, and many other

fields.

Today, no industry sector is competitive with-

out using advanced microelectronic devices.

These devices are the backbone of today’s

innovation enabling many new products from

consumer products to industrial application,

automotive, telecommunication, medical,

and more. These are all sectors where

Europe plays or can play a global leading

role.

There is a broad agreement on how critical

semiconductor technology is for the entire

European industry and our societal chal-

lenges. With the European Commission’s

Key Enabling Technologies (KET) initiative

now in place, there is an epochal opportunity

for the semiconductor industry to make a

quantum leap with regards to Europe’s com-

petitiveness, including manufacturing.

Over the last years, the European semicon-

ductor base was shrinking and an increasing

number of companies have relocated their

activities to other regions. Besides serving a

local market locally they took advantage of

widespread incentives offered by the various

countries mainly in Asia.

Semiconductors are critical to the European

industry and welfare and must be prioritized

to keep leading European industries compet-

itive.

European equipment and materials suppliers

to the semiconductor industry are concerned

by this development as close collaboration

with their customers is required in order to

develop leading edge technology. Although

system integration, R&D and small scale

production might still remain in Europe,

SEMI members in Europe fear that without

major semiconductor manufacturing, eventu-

ally knowledge-based activities will also relo-

cate — with severe consequences for

Europe’s competitiveness.

To keep Europe in the technology race, EU

institutions and member states must rein-

force their commitment to key enabling tech-

nologies.

SEMI Europe welcomes the European Com-

mission’s initiative to advance key enabling

technologies (KET). Following the need to

adopt a European-wide strategy to ensure

European competitiveness, SEMI Europe

supports the Commission which took a sub-

stantial role in addressing pan-European

challenges which cannot be resolved by a

single Member State alone. We recognize

the importance of points raised in the Com-

munication such as state of the art R&D,

importance of Lead Markets, enforcement of

IP Protection, availability of skilled Engineers

and Financing, but SEMI emphasizes the

sense of urgency!

Declare the European semiconductor indus-

try as strategic industry. The benchmark are

the countries in Asia (Taiwan, Singapore,

Korea, China, Japan) and the U.S. that have

declared their semiconductor industry as one

of their top national strategic priorities and

implemented semiconductor supportive

industry policies. Governments in Asia and

the U.S. strongly support the semiconductor

industry by providing significant incentives

for new projects, R&D funding, workforce

development programmes, and a favourable

regulatory environment— resulting in unbal-

anced competition for the European semi-

conductor ecosystem. Therefore, SEMI

expects the EU to restore the level playing

field!

The industry must continue the dialogue with

public authorities to ensure that concrete

measures, that will deliver tangible results,

will be implemented very soon. Solutions

exist, but we must act swiftly, working

together in a concerted manner. This is a

European issue after all, and I welcome sup-

port from organization and companies willing

to help implement solutions.

[email protected]

www.semi.org

G U E S T E D I T O R I A L

Europe’s Competitiveness is at StakeWill we fight the battle or merely observe as our industries relocate?

By Heinz Kundert, President, SEMI Europe

2SP0115T Gate DriverUnleash the full power of your converter design using the new 2SP0115T Plug-and-Play driver. With its direct paralleling capability, the scalability of your design into highest power ratings is unlimited. Rugged SCALE-2 technology enables the complete

the size of 17mm dual modules. Combined with the CONCEPT advanced active clam-ping function, the electrical performance of the IGBT can be fully exploited while keeping the SOA of the IGBT. Needless to say that the high integration level provides the best possible reliability by a minimzed number of components.

FeaturesPlug-and-Play solution1W output power15A gate current<100ns delay time± 4ns jitterAdvanced active clampingDirect- and halfbridge modeDirect paralleling capability2-level and multilevel topologiesDIC-20 electrical interfaceSafe isolation to EN50178 UL compliant50.- USD @ 1000 pieces

www.IGBT-Driver.com

SAMPLES AVAILABLE!

CT-Concept Technologie AG, Renferstrasse 15, CH-2504 Biel, Switzerland, Phone +41-32-344 47 47

UnleashSheer Power!


GENERAL

Top 10 Original Equipment

Manufacturers accounted

for $ 104.3 billion of semi-

conductors on a design

total available market

(TAM) basis in 2010

— over a third of semicon-

ductor vendors' worldwide chip revenue —

so Gartner. This was a year-over-year

increase of 33.7 percent from 2009. The

major growth drivers in 2010 were mobile

PCs, smartphones and LCD TVs.

SEMICONDUCTORS

2010 set an all-time high for semiconductor

dollar content in electronic systems at 25.4

percent, 2.3 points higher than the previous

high of 23.1 percent first reached in 1995

and again in 2006, so IC Insights.

IBM and Samsung will collaborate on basic

research into new semiconductor materials,

manufacturing processes and other tech-

nologies. For the first time, Samsung

researchers will join IBM scientists in the

Semiconductor Research Alliance at the

Albany Nanotech Complex, where

researchers will investigate new materials

and transistor structures, as well as innova-

tive interconnect and packaging solutions for

next-generation technology nodes. The

agreement also renews IBM and Samsung's

joint process development agreement (JDA)

to multiple nodes starting at 20 nm.

ARM and IBM will extend their collaboration

on advanced semiconductor technologies to

enable the rapid development of next gener-

ation mobile products optimized for perform-

ance and power efficiency. The resulting

technology will provide a suite of optimized

physical and processor IP by ARM tuned to

IBM’s advanced manufacturing process

down to 14 nm. Past collaboration with IBM

and ARM on advanced geometries on the 32

nm and 28 nm nodes, has been underway

since 2008.

Infineon has opened a new facility in China

called Infineon Integrated Circuits (Beijing).

In addition to sales and marketing, applica-

tion R&D and central functions, the new enti-

ty houses an IGBT stack manufacturing facil-

ity and a technical centre for automotive

solutions.

This new entity will enable Infineon to raise

its output to meet the expanding demand

especially for energy efficiency and electro-

mobility solutions in China. Today, Infineon

has around 1700 employees in China.

OPTOELECTRONICS

Samsung Electronics has acquired display

technology firm Liquavista, based in Eind-

hoven. Liquavista, founded in 2006 as a

spin-out from the Philips Research Labs,

offers a new type of electronic display tech-

nology known as electrowetting for applica-

tions in e-readers, mobile phones, media

players and other mobile devices. Displays

utilizing electrowetting consume just 10 per-

cent of the battery power of existing display

technologies. In e-paper applications, the

response time of the electrowetting displays

will be more than 70 times faster than that of

existing reflective displays, allowing for color

videos.

The Russian Corporation of Nanotechnolo-

gies (Rusnano) and Plastic Logic have final-

ized details of Rusnano’s investment in the

company, which is the global supplier in the

emerging field of plastic electronics. The

investment project, which will total $ 700 M,

includes building the world’s largest volume

production factory for Plastic Logic’s next-

generation plastic displays in Zelenograd.

Plastic Logic said it plans to employ 300-

plus at the new Zelenograd facility, sched-

uled for production starting in 2013/2014.

Plastic Logic has received an initial invest-

ment package of $ 300 M. Over the next few

years, additional equity and debt will be

raised totaling approximately $ 400 M. Plas-

tic Logic plans the continued investment in

its first high-volume manufacturing facility in

Dresden, Germany, which opened in 2008,

as well as its technology R&D centre in

Cambridge, England.

Building on its leadership in full-color

microdisplay technology for high-perform-

ance applications, Kopin has acquired all of

the outstanding common stock of Scotland-

based

Forth Dimension Displays (FDD), a provider

of alldigital, ultrahigh-resolution, near-to-eye

ferroelectric reflective microdisplays. The

purchase price was approximately $ 11 M in

cash plus an earnout provision if certain rev-

enue milestones are reached within one year

of the purchase date. FDD had approxi-

mately $ 6 M of revenue in 2010.

PASSIVE COMPONENTS

Total sales for Germany’s PCB industry fell

1.6 percent in October 2010 compared with

the previous month, so the ZVEI. Year-on-

year however, sales were up 28 percent.

Cumulative sales from January to October

2010 grew 34 percent compared with the

same period in 2009. New orders in October

2010 confirmed the already expected nor-

malization of orders by year end. Compared

with both September 2010 and October

2009 the number of new orders received in

October 2010 was down by approximately a

third. The book-to-bill ratio fell to 0.66.

OTHER COMPONENTS

GE has signed an agreement to acquire Lin-

eage Power from The Gores Group. Lineage

Power is a provider of power conversion

infrastructure technology and services for

telecommunications and datacentre indus-

tries.

DISTRIBUTION

Avnet Abacus, a highly-focused electronic

component distributor specialising in inter-

connect, passive, electromechanical, power

supply and battery products, has announced

a new pan-European franchise agreement

with specialist waterproof connector and

cable assembly supplier Amphenol LTW. The

agreement makes Avnet Abacus the first

EMEA distributor for Amphenol LTW.

Maxim Integrated Products which sells high-

performance semiconductor products has

signed Mouser Electronics, as a global cata-

log distributor. Maxim recognizes that cata-

log distributors provide the engineering com-

munity with the added value of online design

tools, a broad range of in-stock products,

and fast global delivery.

This is the comprehensive power related

extract from the « Electronics Industry Digest

», the successor of The Lennox Report. For

a full subscription of the report contact:

[email protected]

or by fax 44/1494 563503.

www.europartners.eu.com

M A R K E T

ELECTRONICS INDUSTRY DIGESTBy Aubrey Dunford, Europartners

The elimination of the need to maintain multiple external power sup-

plies, one for each electronic device, has long been a goal for both

the consumers and manufacturers of consumer electronics equip-

ment. As a result, a number of organizations, regulatory bodies and

individual companies are working toward the development of a uni-

versal power adapter solution. One of the more recent efforts towards

the elimination of multiple ac-dc adapters has been by the Interna-

tional Electrotechnical Commission (IEC), who announced the publi-

cation of the first globally relevant universal phone charger standard

for data-enabled mobile telephones, the IEC 62684 ed1.0. This new

IEC International Standard covers all aspects of the charger, connec-

tor and plug, as well as safety, interoperability and environmental

considerations.

The standard defines the common charging capability and specifies

interface requirements for the external power supply. It is designed to

encourage a significant reduction of mobile phone-related electronic

waste and, when widely adopted by industry, will allow consumers to

use a single one-fits-all charger with all new smartphones. Manufac-

turers will be able to achieve cost-savings in production, packaging

and shipping, since they will no longer need to provide a charger with

each phone. This may also positively impact end-consumer prices

and will reduce the overall CO2 footprint of this industry, potentially

cutting greenhouse gas emissions by 13.6 million tons per year

The heart of the standard is based on the micro USB plug specifica-

tions issued by the USB-IF (Implementers Forum), with which the

IEC has recently signed a MoU (Memorandum of Understanding).

The new IEC International Standard comprises input from all relevant

sources, including the work developed by CENELEC and ITU-T, with

which the IEC has a long-standing cooperation agreement. Since

USB technology is well accepted globally, it was decided that it

should be included in the standard, which was also based on specifi-

cations by more than a dozen phone manufacturers, including Apple,

Nokia, Research in Motion, Emblaze Mobile, Huawei Technologies,

LGE, Motorola Mobility, NEC, Qualcomm, Samsung, Sony Ericsson,

TCT Mobile (ALCATEL), Texas Instruments and Atmel, all of which

have signed an MoU with the European Commission.

In another development likely to have a significant impact on the

manufacturers of external power supplies, the Institute of Electrical

and Electronics Engineers (IEEE) has initiated a project to establish a

standard smart dc power supply that could eventually eliminate the

need to carry around multiple power adapters. The project was initiat-

ed in 2009 and finally made the news in 2010 when it received the

backing of a number of Taiwanese manufacturers. In order to see this

project through, the IEEE initiated a working group called P1823

whose goal is to develop a specification for what it calls a “universal

power adapter for mobile devices” – shortened to UPAMD. The IEEE

P1823 Working Group is attempting to obtain agreement between

electronics manufacturers and vendors on a common interconnection

for power delivery to portable and fixed electronic devices.

The establishment of an industry-wide standard is viewed by many

as a critical step toward the replacement of brand- and model-specif-

ic analog power adapters (which often end up in landfills as people

upgrade their computing, entertainment, household and office equip-

ment) with digital power supplies that can be used and reused with

multiple devices. The term UMPAD could turn out to be a misnomer,

because they could also eventually be used to power typical house-

hold devices such as hi-fi equipment and televisions. In fact,

UPAMDs could eventually be fitted as a standard feature in homes,

hotel rooms, trains, aircraft and cars so that a dc supply becomes as

ubiquitous as the mains.

One of the few parameters already decided for the UPAMD is that it

should be capable of delivering between 10W and 130W per connec-

tion, which should be more than enough for power-hungry devices

like laptops and printers. An adapter with just one output might look

like a standard laptop power brick, but differs in that it can power any

UPAMD-compliant device. Also, a UPAMD client can itself act as a

UPAMD source, allowing a user to power one laptop from another

when the battery runs flat.

In addition to the standards associations mentioned, a number of pri-

vate organizations are also actively involved in establishing a set of

working standards for the external power supply industry. In October

of 2010, Green Plug, a developer of digital technology enabling col-

laboration between multiple electronic devices and their power

sources, announced its support for the recently formed Institute of

IEEE Standards Association P1823 working group, which was creat-

ed to develop a specification for universal power adapters for mobile

devices. According to Green Plug, by bringing together all the parties

with a stake in the migration to a universal smart power interface, the

IEEE is helping to break down the product silos and other barriers

that have delayed the broad adoption of universal power adapters for

mobile and other devices.

Green Plug has been a long-time advocate for the voluntary adoption

of a standard smart power protocol for many years. According to

Green Plug, developing a standard power interface is not an easy

task, as there are dozens of technologies and architectures to be

considered – each with its own specific trade-offs. In an effort

towards developing a working standardization process, Green Plug

has evaluated a variety of options and has developed a number of IP

solutions for electronics vendors that minimize trade-offs normally

associated with flexibility, size and cost. Green Plug offers technology

designed to make any electronic product capable of receiving power

from any power supply.

There are also a number of organizations who are advocating the fur-

ther advancement of wireless charging solutions. The Wireless

Power Consortium is one of them, and they recently completed the

Qi Low Power Standard, where up to five watts can be transmitted

wirelessly. The objective of the Wireless Power Consortium is to

establish the Qi Low Power Standard as the global standard for pow-

M A R K E T


New Threats to External ac-dc Power Supplies

By Richard Ruiz Jr., Research Analyst, Darnell Group

ering rechargeable electronic products. According to the consortium,

a universal standard in wireless charging is inevitable. The 69 mem-

bers of the Wireless Power Consortium include industry leaders in

mobile phones, consumer electronics, batteries, semiconductors,

components, wireless power technology and infrastructure such as

wireless operators, furniture and automotive parts companies.

Among the more prominent members of the consortium are LG Elec-

tronics, Philips, Nokia, RIM and Duracell.

Manufacturers of external power supplies should monitor these

developments closely, because the resources, technology and effort

directed towards eliminating the need to maintain multiple external

power supplies indicates a serious trend in the industry.

Information on Darnell’s just-released market research report on

External AC-DC Power Supplies is available at:

www.darnell.com/externalacdc


ABB FranceCurrent & Voltage Sensors Departemente-mail: [email protected]

Improve magneticImmunity?

Absolutely.

For ABB protecting the environment is a genuine priority, as witness our ISO 14001 certificationobtained in 1998.We believe that wind generators represent the future in renewable energy, that’s why ABBsensors team puts its experience and its know-how at its customer’s disposal and works closelywith them in order to have the right product for their application, with improved immunity andcompactness.You have a dedicated application, we have a dedicated range. www.abb.com

22 Bodo´s Power Systems® February 2011 www.bodospower.comBodo´s Power Systems® March 2011 www.bodospower.com

Surprisingly, it is not so much a case of the semiconductor silicon

causing problems. It's rather a question of the required "standard

auxiliary components", such as heat sinks, capacitors, clamping

devices and auxiliary voltage supplies, which no longer meet higher-

level requirements concerning insulation properties in medium volt-

age applications.

This mainly affects auxiliary power supplies used to power IGBT,

IGCT and GTO driver boards, for example. First and foremost, auxil-

iary power supplies must provide reliable galvanic insulation between

the medium voltage level and the power side. The "insulation volt-

age" specification in the data sheet is less informative. It simply

states that the auxiliary voltage supply was applied under the con-

straints specified, and with the voltage value specified, without there

being a disruptive breakdown. It does not state whether the auxiliary

voltage supply may be operated continually under these voltage con-

ditions without there being deterioration, and hence damage to the

insulation barrier.

The requirements for made of insulation in medium voltage applica-

tions are laid down in IEC 60071 standards as regards test condi-

tions, creepage distances and air gaps.

These are, in short:

• Creepage distance 20 mm/kV for pollution degree 2

• Creepage distance 25 mm/kV for pollution degree 3

• Insulation test voltage in accordance with the standard applied

(generally twice the nominal voltage)

• There must be no partial discharges in the range of rated voltage

load

New 4-channel auxiliary voltage supply in the GIS18 family with

higher insulation voltage

In the development of auxiliary power supplies with insulation in the

two-digit kV range, best possible insulation must take top priority. It

must be free of partial discharges during operation to withstand high

voltages over a long time.

Partial discharges occur whenever the electrical field causes exces-

sive peaks in local field strength leading to overstressing of the insu-

lation material.

Once impaired, insulation gets more and more susceptible for dis-

charges resulting in long-term damage and disruptive breakdowns.

Irregular, sharp-edged geometries always result in non-homogenous

electrical fields. Ideally, uniform field strength distribution is achieved

in the homogenous field of a plate-type capacitor. Because of that the

insulation barrier has been implemented in a similar way in GIS18

voltage converters.

Situated between two electrically conducting potential surfaces is the

insulation barrier which has a uniform thickness of a few millimetres.

The edges of the potential surfaces are rounded. Energy is trans-

ferred via the insulation barrier, which runs centrally through the

transformer of the switch converter. Therefore the ferrite core has

been split into two halves. On one half of the core is the primary coil,

on the other half the secondary coil.

C O V E R S T O R Y

Auxiliary Power Supplies forMedium and High Voltage

ApplicationsNew IGBTs and IGCTs, together with appropriate snubber and freewheeling diodes up to

5.5 kV (6.5 kV respectively), are opening up the possibility of establishing power electronics for the medium voltage level with manageable effort. Tri–level switchingtopologies and cascaded switching systems are the preferred architectures used here.

By Werner Bresch, Managing Director of GvA Leistungselektronik GmbH, andDr. Henrik Siebel, Managing Director of Siebel & Scholl GmbH

Figure 1: Auxiliary voltage supplies provide galvanic insulationbetween medium voltage level and power side

fiber opticfiber opticd i idata transmission

powert l powert k

controlstackunitunit

GIS18

auxiliaryauxiliarypowerpower

lsupplylow voltage medium voltagemedium voltagelow voltage

< 1kVmedium voltage

1kV 25kVginsulation< 1kV 1kV - 25kVinsulation

www.bodospower.com Jan

High insulation voltage, free of partial discharge

The new 4-channel GIS18 voltage converters have been specially

designed for the requirements in 3- and 5-level medium voltage

inverters. They therefore have four supply channels which are gal-

vanically insulated from each other. Their insulation voltage rating

allows GTO and IGCT driver boards to be supplied directly with suffi-

cient power. Devices with 35 VDC and 35 VAC (70 kHz square wave)

output voltages are available. The 70 kHz square-wave provides the

option to convert the given output to another voltage level (e.g. as

required to power IGBT-driver boards).

When all four supply channels are used simultaneously, an output

rating of 75 W per channel is available. If not all the supply channels

are used simultaneously, the applied load for a supply channel may

be up to 150 W.

The insulation voltage between individual supply channels is 10

kVAC (without partial discharge). Between supply channels and

ground potential, the insulation voltage is at least 18 kVAC, 50 Hz, 10

sec, without partial discharge (<10 pC).

The couple capacity between primary and secondary sides is only 30

pF, resulting in a high dv/dt immunity of up to 25 kV/us.

Wide voltage input with PFC (Power Factor Correction)

On the primary electronic of the GIS18 is an uncontrolled rectifier

with a downstream PFC stage on the input side. This allows for the

implementation of a DC/AC wide voltage input. A voltage of 110 VDC

to 300 VDC, or alternatively 110 VAC to 250 VAC, can be applied as

www.bodospower.com

Figure 2: The GIS18 (right) with four channels guarantees an insula-tion strength of min. 18 kV; on the left is the single-channel SW32variant

Figure 3: Application example: Powering four IGCTs in one IGCT 3-level phase component

35V DC35V DC

35V DCoptical 35V DCopticalfeedbackfeedback

35V DC35V DCinput voltageinput voltage

35V DCGIS18 35AD 35V DCGIS18-35AD

Sound Technology With VisionSonoscan—trusted for over 30 yearsby the industry’s leading companies.

Example of an actual Sonoscan® C-SAM ® acoustic scan showing defects in the Thermal Interface Material of an IGBT. The image shows areas of thematerial that are too thick (red), too thin (purple) and void (white), can lead to thermal overload.

Sonoscan, Inc., Corporate Headquarters: 2149 E. Pratt Blvd., Elk Grove Village, IL 60007T: 847.437.6400 F: 847.437.1550 www.sonoscan.com

Silicon Valley, CA Phoenix, AZ England Philippines Singapore Shanghai

but was it made to your design?

You designed it to be cool ...

Too thick, too hot.

Just right!

Too thin, too hot.

Efficient cooling is the most

important feature of IGBTs

and power modules.

While they are

designed to match

specific requirements, they are not always

manufactured as expected, causing thermal

overload, hard failures or inefficient operation.

Sonoscan’s C-SAM technologies nondestructively

detect and measure substandard devices better

than any other inspection method.

To learn more about how Sonoscan’s advanced AMI technology and unique patented features can help you ensure efficient cooling, visit www.sonoscan.com.


input voltage. The PFC stage provides a power factor of 1 on the

supply side and a stabilized DC voltage supply for the power inverter

at the same time. The transformer has comparatively high stray

inductances and only a moderate coupling between primary and

secondary coils of about 30–50%. Classic switch converter topolo-

gies such as flyback converters and forward converters cannot be

used on this transformer.

In GIS18 a resonance converter is used, on which resonance capaci-

tors are arranged in series with the transformer coil on the input and

output sides. These capacitors are designed such that the stray

inductances of the transformer are compensated. This enables

transfer of energy despite the moderate coupling.

Under normal operating conditions the power inverter is operated

with fixed duty cycle and a frequency of 70 kHz. In the event of a

short-circuit on the output side, the output frequency is changed to

prevent destroying the GIS18 auxiliary voltage supply resulting the

device being short-circuit-protected.

Furthermore, the GIS18 offers diagnostics and a fault reporting sys-

tem. Output overload, input undervoltage and overtemperature can

be detected. Fault situations are reported via an optical fault output,

enabling them to be read and analysed by the control electronics.

Outlook: 4-channel auxiliary voltage supply with very high insu-

lation voltage

Based on the technology presented here, and the empirical values of

single-channel auxiliary voltage supplies with even higher insulation

voltages, Siebel & Scholl is currently developing on voltage supplies

in the GIS18 family with even higher insulation voltages. The proper-

ties of the GIS18 essentially remain the same, but insulation voltages

of up to 40 kVAC without partial discharge should be achieved.

Customized other input and output voltages are available on request.

Single-channel SW32 auxiliary voltage supply

The predecessor to the 4-channel GIS18 auxiliary voltage supply pre-

sented here is the single-channel SW32 auxiliary voltage supply. This

is broadly identical to the GIS18 with respect to inverter, transformer

and output voltages. However, the input side is different. Whereas

the GIS18 has a wide voltage input and a downstream PFC stage,

the SW32 requires a stabilized input voltage of 24 VDC. The output

voltage is as on the GIS18, 35 VDC or alternatively 35 VAC, 70 kHz,

but the insulation voltage is different: 30 kVAC without partial dis-

charge.

This makes the SW32 an ideal auxiliary voltage supply for switching

power semiconductors connected in series, cascaded systems and

multi-level switching topologies.

The following application example shows a solution in which a SW32

powers twelve IGBTs connected in series. Reliable galvanic insula-

tion from earth potential is implemented by the SW32. In the 35 VAC,

70 kHz output there are 12 transformers which carry out voltage

adaptation for the IGBT driver boards and provide the base insulation

between individual IGBTs.

www.gva-leistungselektronik.de

C O V E R S T O R Y

Figure 4: Schematic block diagram of the GIS18

DC AC / AC AC / DCDCAC / DC DC35V DC + A

DC110 - 300V DC 35V DC + A

DCor

AC 70 kHz transformer rectifierDCrectifier110 - 250V AC AC 70 kHz transformer rectifierrectifier

powerfactor

stabilizedfactorcorrection

DC linkAC / AC AC / DCcorrection AC / AC AC / DC

35V DC + A

transformer rectifier

AC / AC AC / DCAC / AC AC / DC

35V DC + Asupervisionti loptical

i i t f tifisupervisionfeedback

transformer rectifierfeedback overload

undervoltageshort circuit

t tAC / AC AC / DC

35V DC + Aovertemperature

C C C C

35V DC + A

transformer rectifiertransformer rectifier

Figure 6: Block diagram of the SW32

AC / AC AC / DCDC

AC / AC AC / DCDC

35V DC AC24V DC 35V DC + AC24V DC

AC 70 kHz transformer rectifierAC 70 kHz transformer rectifier

Figure 7: A SW32 powers 12 IGBT driver boards connected in seriesand implements the base insulation from earth potential

SW32 24D35U IGBTSW32-24D35U IGBTd i b d35V AC driver board35V AC

70 kHzDCIGBT

70 kHzDCIGBT

driver board24V DC driver board

ACIGBT

ACIGBTdriver boarddriver board

transformer + rectifier...

Figure 5: Every GIS18 is subject to intensive high-voltage testingprior to delivery

��

��

�� !�� "�� #$%�&��

�%'()*�� + ��,��

��

�� !"�#$��%��$��

��&�'�#��(�� #)�*�%��

%��+��$�� #

�� #�� $��

,��-��

�� #�� !��

"��. !"�/ ��

��

��

��

This article is intended to explain the component parameters in more

detail, point out possible differences in how the different parameters

are determined and help users analyse data.

Conducting current

Normally, comparisons are done on the basis of the nominal IGBT

current. What must be borne in mind here, however, is that different

current data exist, which, if incorrectly interpreted, may lead to mis-

understandings. The “nominal current” ICnom is the nominal current of

the chip area used and is calculated from the current density per

mm² defined by the manufacturer for the chip technology. None of

the properties relating to the module design are factored into this cal-

culation. The forward voltages and switching losses are given for this

current. The IC specified in the “maximum ratings”, in contrast, refers

to the direct current which can be continuously conducted by the

IGBT at a certain case temperature. This value of current is deter-

mined for a component with maximum forward voltage and using the

maximum junction temperature. This specification includes both the

electrical and the thermal properties (Rth) of the module. As a result

of additional switching losses and a safety margin in junction temper-

ature, this value can seldom be achieved in practice. For some mod-

ules, the maximum current is limited by the terminals rather than the

chips; in such cases, the maximum terminal current (It(RMS)) must

be specified.

The data specified for the forward voltages VCE(sat) for the IGBT and

VF for the freewheeling diode should actually relate to the main termi-

nals of the modules, i.e. they should be specified at terminal level.

This includes voltage drops across the terminals. Owing to higher

power densities and improved semiconductor properties, the terminal

losses are no longer negligible as compared with semiconductor

losses. For thermal dimensioning, it therefore makes sense to specify

the voltage drop across the chips (i.e. at chip level) and across the

terminals (rCC’-EE’) separately. The voltage across the terminals is

as follows:

The separate specification offers the user the advantage that he can

calculate chip losses and terminal losses separately. For instances, a

300A current causes in a module with rCC’-EE’ = 1mΩ terminal losses

of 90W. In comparison: the four semiconductors in this half bridge

module (2 x IGBTs + 2 x diodes) cause, for this current, around 700…

800W losses. Only the losses in the chip are relevant for chip heating.

The data specified for VCE0 and rCE come from a straight line approx-

imation of the forward characteristic, generated through the points at

25% and 100% of the ICnom, as shown in the example in Fig. 1.

These are auxiliary values that are obtained by calculation and are

intended to help users calculate power losses. A comparison of for-

ward voltages is to be performed for the same, high chip tempera-

ture, the measuring point (chip or terminal) and measuring current

(ICnom). Not all manufacturers include the measuring point is the

datasheet. A tip for chip-level measurements is that here the values

for VCE(sat) for all IGBT modules of one chip technology are largely

the same. For terminal-level measurements, the data specifications

depend on ICnom.

Switching

Switching energy (Eon, Eoff, Err) and switching times (td(on), tr, td(off), tf,

trr) are not only dependent on the semiconductor itself, but also on

the surroundings. Stray inductance, driver output or motor cable and

filter capacities affect the switching behaviour. The datasheet values

are therefore to be regarded as typical values only. When comparing

different datasheets, or even when looking at lab measurements in

comparison to practical results, a number of essential factors must be

taken into account. The majority of manufacturers, including SEMI-

KRON, refer to switching behaviour under inductive load, since this is

closest to actual usage in drive applications. A few manufacturers

CErmsCCEavCv rIVIP ⋅+⋅= )(0)(

''min EECCCCEchipalCEter rIVV −⋅+=

I G B T S


Comparing theIncomparableUnderstanding and comparing

IGBT module datasheetsThis might sound somewhat overdone but comparing IGBT modules using datasheets isnot as easy at is might appear. A rough comparison can, of course, be made using the

component blocking voltage (VCES, e.g. 1200V) and the nominal current (ICnom = 100A, 200A…). On closer inspection, however, the user might be confused bythe different measurement conditions, as well as different definitions and designations.

Dr. Arendt Wintrich, Application Manager, Semikron

Figure 1: Differentforward charac-teristics of a 400ASEMITRANSmodule at chiplevel and terminallevel, incl. theequivalentstraight lineresulting fromVCE0 and rCE

specify data for ohmic load, resulting in far lower switching losses

and switching times. A further reason why differences occur lies in

the different limits of integration, between which the switching energy

is determined from the switching losses as a function of time. These

limits should start and finish at 1…2% of the increasing or decreasing

value, respectively. The use of 10% limits, as is the case when defin-

ing switching times, results in too low a result for switching losses.

Data relating to load conditions and integration limits can be found in

manufacturers’ technical explanations or application notes.

Comparisons of switching energies are often done for identical gate

resistance RG, because the switching speed is related to RG. This is,

however, not always possible, even for the same chip technology,

since both positive and negative feedback effects in the control circuit

determine the switching speed. A better approach would be to per-

form a comparison for identical diC/dt and dvCE/dt, since here the

interference levels are comparable. When looking at the power loss-

es, a change in gate resistances has to be taken into account in

accordance with the curve Esw= f(RG). This curve begins at a value

that is not specified directly as the minimum gate resistance, but at

which the IGBT can still be safely switched. Smaller RG values are

not ruled out, but ought to be verified with the manufacturer first.

Stray inductance in the commutation circuit means a reduction in

turn-on load and, especially in the case of low DC link voltages (e.g.

300V), ensures very low turn-on losses. This is largely offset by a

turn-off overvoltage, which is why in hard switching applications the

sum of the turn-on and turn-off losses has to be considered. Switch-

ing losses normally specified only depend on the current. Other

parameter that are important for switching energy comparisons are

the voltage applied and the junction temperature. The following for-

mulae can be used to apply the point of reference “ref” to other con-

ditions, resulting in an acceptable approximation:

Gate charge QG may be specified in the datasheet for different turn-

off voltages (negative driver voltage -15V/-8V/0V). If a curve is given

for positive voltages only, the curve can be extended into the nega-

tive area from voltage rise above the voltage plateau. QG is only

slightly dependent on the DC link voltage, since this voltage is need-

ed to charge the Miller capacitance. For high voltages, the capaci-

tance is very low, which is why the influence on the gate charge is

minimum, too. Temperature dependency is negligible.

Heat dissipation

The ability to dissipate heat is specified by the value Rth. In power

semiconductor modules, the assumption is made that the total heat

losses are dissipated via the assembly (module) surface. The thermal

resistances are calculated from the temperature difference between

two measuring points (T1, T2) and the power dissipation (Pv).

Different choices of measuring points can lead to variations in the

shares in the thermal resistances (see Ts1 and Ts2 in Fig. 2). For the

specification of Rth for chip (junction) to base plate (case) Rth(j-c), this

is still relatively uniform. Here, the measuring point for base plate

temperature is directly beneath the chip. For the specification of Rth

between base plate and heat sink (Rth(c-s)), however, there are a

variety of definitions. The temperature of the heat sink surface is

higher underneath the module than beside it. SEMIKRON specifies

the Rth(c-s) for a measuring point Ts1 beside the module.

The relatively high temperature difference at this point leads to a high

value for Rth. Other manufacturers' specifications for this value are

based on the measuring point Ts2. The low temperature difference

from the base plate to this hot spot results in a low value for Rth.

This is why the Rth values specified for identical-sized, standard

module cases are often very different.

Rth(c-s) can continue to be specified per module or per semiconductor.

One-dimensional modelling using thermal resistances always leads

to an error with regard to the thermal coupling between the individual

components in a module. For specification of Rth(c-s) per semiconduc-

tor, thermal coupling between the semiconductors is, despite good

conducting copper base plate, completely neglected. If Rth(c-s) is

given for the entire module, this means full coupling between the

semiconductors of one module. In addition, Rth(c-s) is, of course, also

dependent on the module assembly, for example the screw tightening

torque, the heat sink quality or the thickness and heat conductivity of

the thermal paste, which is why this value can be given as a typical

value only.

For modules with no base plate, the “base plate temperature” point is

not accessible for measurements, which is why in this case Rth(j-s) is

specified directly from chip to heat sink underneath the chip. As a

result, the total Rth(j-s) to heat sink is to be used when comparing

modules with and without base plate.

Conclusion

A comparison of the static IGBT parameters of different manufactur-

ers and modules may well be done if a number of steps are followed.

With a number of restrictions, the same applies to thermal resistanc-

es, provided the relevant measuring points are known and the entire

path from chip to cooling medium is factored in. The most difficult

comparison is that of the switching properties. Here, it is vital that the

di/dt or dv/dt is taken into account. The ideal situation would be to

perform a direct comparison in actual application, factoring in temper-

ature, losses and interference radiation measurements.

Manufacturers of IGBT modules offer users support in the form of

tools which can be used to calculate power losses and temperature

[http://semisel.semikron.com/] under application-like conditions. Such

calculations provide more meaningful results as regards the suitability

of a module than pure datasheet-based considerations.

www.semikron.com

)()()( scthcjthsjth RRR −−− +=

vth P

TTR 21)21(

−=−

( ) ))(006,01(:

6,06,0

refjCCref

CC

Fref

Frefrrrr TT

VV

IIEEFWD −⋅+⋅⎟

⎟⎠

⎞⎜⎜⎝

⎛⋅⎟

⎟⎠

⎞⎜⎜⎝

⎛⋅=

( ) ))(003,01(:

35,1

refjCCref

CC

Cref

Crefoffonsw TT

VV

IIEEEIGBT −⋅+⋅⎟

⎟⎠

⎞⎜⎜⎝

⎛⋅⋅+=

I G B T S


Figure 2: Possible reference points for temperature measurement inIGBT module and the resultant, different shares in the calculatedthermal resistances

Rth(s-a)1

Rth(c-s)1

Rth(j-c)

Rth(s-a)2

Rth(c-s)2

Layers of an IGBT module on a heat sink:

Power semiconductorCeramic (DBC)

Heatsink

Thermal grease (TIM)

Base plate

Ta

TcTs1

Tj

Ts2

This article investigates the influence factors for improving the body

diode ruggedness. The benefit of this Superjunction device family

with fast body diode is especially shown for a HID half-bridge topolo-

gy.

Introduction

With the increasing demand for higher power density, especially soft

switching topologies like half-bridge (e.g. HID half-bridge or LLC) and

full-bridge concepts (e.g. ZVS bridge) seem to be the ideal solution.

These topologies reduce the switching losses and increase the relia-

bility of the system due to less dynamic di/dt and dv/dt stress on the

power device. Such high stresses occur predominantly in light-load

operation [1]. It is already shown that Superjunction devices like the

CoolMOS™ help to overcome this problem by inherent optimized

charge carrier removal during reverse recovery and eliminating the

problem of latch-up of the para-sitic npn-bipolar transistor [2]. A sig-

nificant reduction of the reverse recovery charge can be achieved by

an enhanced recombination rate of the injected carriers resulting in

lower reverse recovery peak currents during turn-off and strongly

reduced reverse recovery charge by almost a factor of 10. For opti-

mized body diode (Figure1) performance in hard switching condi-

tions, especially the shape of the resulting reverse recovery wave-

form and the design conditions

of the printed circuit board are

important [3-4]. The 650V

CoolMOS™ CFD2 is de-

signed in this manner with

improved reverse recovery

behavior together with

increased safety margin in

breakdown voltage.

Reverse Recovery Behavior

The reverse recovery behavior of the new 650V CoolMOS™ CFD is

shown in Figure 2. It appears that the new 650V CoolMOS™ CFD

devices have a very low reverse recovery charge Qrr, reverse recov-

ery time trr and maximum reverse recovery current Irrm when com-

pared to the standard device.

At the same time, the waveforms of the new device still show a soft

characteristic, in spite of the strongly reduced Qrr, trr and Irrm. This

characteristic is highly desirable during hard com-mutation in order to

avoid voltage overshoot and to ensure reliable device operation.

Commutation Ruggedness

The commutation ruggedness of the 650V CoolMOS™ CFD device is

demonstrated in reverse recovery measurements in Fig. 3, where the

devices were tested up to di/dt ≈ 2000A/μs.

No device could be destroyed under these conditions and the wave-

forms show still a soft characteristic, compared to snappy waveforms

for other superjunction devices. This is a clear advantage for the

M O S F E T


650V Super Junction Devicewith Rugged Body Diode

Perfect for hard and soft switching applicationsWith the 650V CoolMOS™ CFD2 technology a benchmark is set for high voltage power

MOSFETs with a high performance integrated body diode. The transistor combines ahigh blocking voltage of 650V with lowest Rdson and low capacitive losses together withan improved body diode ruggedness during reverse recovery especially for hard and soft

switching applications. Together with the improved performance a specification of themax-value of the Qrr and trr in the datasheet will be introduced.

By M.-A. Kutschak and W. Jantscher, Infineon Technologies Austria AG, Siemensstraße 2, A-9500 Villach, Austria and

D. Zipprick and A. Ludsteck-Pechloff, Infineon Technologies AG, Am Campeon 1-12, D-85579 Neubiberg, Germany

Figure 1: Schematic crosssection of the CoolMOS highvoltage power MOSFET andits integral body diode

Figure 2: Measured reverse recovery waveforms at di/dt=100A/μs,25°C, Vr=400V. The CFD device shows very low Qrr, trr and Irrm whencompared to the standard device.

designer, once one can optimize its application for maximum per-

formance without being concerned with device destruction during

hard commutation of the body diode.

Dependence of Qrr and trr with temperature

Of utmost importance for the designer is the dependence of Qrr and

trr on temperature. The Qrr and trr values tend to increase with tem-

perature, due to increased carrier generation in the device. This

dependence is shown in Figure 4 for the 310mΩ 650V CFD2 device.

A linear in-crease of Qrr and trr with temperature is observed.

Dependence of Qrr and Trr with Rdson

Another important aspect to be considered is the dependence of Qrr

and trr on the device Rdson. This can be seen in Figure 5 and

Figure 6, respectively, where the new 650V CFD2 device is com-

pared with the former Infineon’s CoolMOS™ fast diode technology.

The 650V CFD2 device clearly offers an even better trade-off then

the former technology be-tween dynamical characteristics (Qrr, trr)

and lowest Rdson.

Performance Evaluation in HID-Bridge

We have also compared the performance of the new devices with the

commercial available SPD07N60C3 in a HID half-bridge application.

Using the new CoolMOS™ CFD2 devices, the diodes D2, D3, D4

and D5 can be eliminated and allow reduced system costs (Figure 7).

M O S F E T


Figure 3: Measured reverse recovery waveforms for the new 650VCoolMOS CFD2 de-vice. The devices could not be destroyed even at the maximum capability of the tester

Figure 6: Dependence of trr on Rdson, measured at 25°C and for the 80, 310 and 660mΩ 650V CFD2 devices in comparison with theformer 600V CFD technology

Figure 7: Typical HID Half-Bridge circuit. By replacing the transistorsT2 and T3 with the new CoolMOS™ 650V CFD2 device, the diodesD2 to D5 can be eliminated

Figure 8: Circuit wave forms during the turn-off phase of transistor T3with SPD07N60C3 as switch and the diodes D2 – D5. An efficiency of 91,81% is achieved.

Figure 4: Dependence of Qrr and Trr with temperature for the 310mΩ650V CFD device

Figure 5: Dependence of Qrr on Rdson, measured at 25°C and for the80, 310 and 660mΩ 650V CFD2 devices in comparison with the for-mer 600V CFD technology

For reference Figure 8 shows, the wave forms obtained by using

the SPD07N60C3 device as transistors T2 and T3 and additionally

the diodes D2, D3, D4 and D5. With this setup, we achieved an

efficiency of 91,81%.

By removing the diodes in series to the transistors, the additional

voltage drop in forward op-eration is eliminated. This solution

requires, however, an even superior performance of the internal body

diode of the MOSFET once the switching losses increase due to the

reverse recovery charge stored in the MOSFET. This situation is

depicted in Figure 9.

In addition to increased switching losses, this setup also has the dis-

advantage that the MOSFET’s can eventually be destroyed due to

the high reverse recovery current.

A superior solution is achieved by using the new IPD65R660CFD

device. Due to the superior performance of the internal body diode of

the MOSFET, it is possible to implement a solution without the diodes

D2-D5 and obtain at the same time a considerably better efficiency.

This is shown in Figure 10.

The optimized construction of the internal body diode of the new

IPD65R660CFD device combined with a very low reverse recovery

charge also enable reliable device operation.

Conclusion

Infineon’s CoolMOS™ CFD2 device, offers the lowest RDS(on) com-

bined with a high blocking voltage of 650V. This new device features

also a very low reverse recovery charge combined with a robust inte-

gral body diode. A specification of the max-values of the Qrr and trr

will be available in the datasheet. We have also evaluated the per-

formance of this new device in a typical HID Half-Bridge circuit, leav-

ing out four diodes and getting superior efficiency. Due to the break-

down voltage of 650V and the robust construction of the integral

body diode, this new device offers additional safety against destruc-

tion during hard commutation of the MOSFET.

Literature

[1] L. Saro, K. Dierberger and R.Redl, “Highvoltage MOSFET behav-

ior in soft-switching converters: analysis and reliability improve-

ments”, Proc. INTELEC 1998, pp. 30-40, San Francisco, Oct.

1998

[2] W. Frank, F. Dahlquist. H. Kapels, M. Schmitt, G. Deboy, “Com-

pensation MOSFETs with fast body diode – Benefits in Perfor-

mance and Reliability in ZVS Applications“, Proceedings-CD of

the International Power Electronics Component Systems Applica-

tions Conference (IPECSA), San Francisco, California, March 29

– April 1, 2004

[3] R. Ng, F.Udrea, K.Sheng, G.A.J.Amaratunga, “A Study of the

CoolMOS Integral Diode: Analysis and Optimization”, The 24th

International Semiconductor Conference; CAS 2001, October

2001, Sinaia, Romania.Grütz, A.: Jahrbuch Elektrotechnik '98.

Berlin-Offenbach: VDE-Verlag, 1997.

[4] R.K.Burra, K.Shenai, “CoolMOS Integral Diode: A Simple Analyti-

cal Reverse Recovery Model”, Power Electronics Specialist Con-

ference, 2003. PESC '03. 2003 IEEE 34th Annual.

www.infineon.com/power

M O S F E T


Figure 9: Circuit wave forms during the turn-off phase of transistor T3 with SPD07N60C3 without the diodes D2–D5. An efficiency of 89,72% is achieved.

Figure 10: Circuit wave forms during the turn-off phase of transistorT3 with IPD65R660CFD without the diodes D2–D5. An efficiency of 92,81% is achieved

Capacitors for Power Electronics

IGBT SnubbersRF Mica Capacitors

AC Output Harmonic Filter Capacitors

CORNELLDUBILIERCDE

www.cde.com/bodo1

DC Link Capacitors -High Current, High Voltage Film -High Capacitance Aluminum Electrolytic


The basics of H-bridge drivers and the advancement of the technolo-

gy from discrete solutions to highly integrated ICs will be discussed

below, complemented by a comparison of linear motor speed control

with more advanced, higher efficiency pulse-width modulation (PWM)

techniques.

Rohm offers a unique product family incorporating numerous

advanced features including high-efficiency PWM outputs, integrated

timing and control circuitry as well as the unique capability of han-

dling either analog or digital (PWM) speed control inputs. The article

will also describe the benefits of these advanced ICs particularly in

terms of their exceptional efficiency, integrated fault protection, small

package size, symmetrical pin configurations and pin-compatibility

with earlier (linear output) models. Finally, a summary of Rohm´s

range of H-bridge ICs including devices specified with 7 V, 18 V and

36 V VCC, as well as single packages containing two selected

(matched) drivers is presented.

H-Bridge Basics

The H-bridge circuit derives its name from the full-bridge circuit. The

motor forms the cross-piece in the “H.” Speed and direction are con-

trolled as current flows through the motor in the direction determined

by the position of the switches in the bridge. In this example, with

switches A and D closed, the motor will operate in a clockwise (CW)

direction. With B and C closed, the motor will operate in the counter

clockwise (CCW) direction.

In the linear output control implementation, the motor speed control is

determined by the voltage applied across the motor. In the PWM

implementation, the speed is controlled by the width of series of puls-

es of equal voltage. In either case, motor direction is controlled via

separate logic inputs.

While the concept is simple, implementation is anything but simple if

discrete components are employed. Controlling the operation of the

switches and preventing simultaneous closure of the CW and CCW

control outputs, particularly when reversing the direction of the motor

or changing speed by dynamic braking requires an H-bridge con-

troller. The H-bridge controller is then connected to four devices form-

ing the legs of the bridge. In a discrete solution the designer must

deal with voltage control levels, timing to prevent shoot-through and

the proper selection of the semiconductor switches. The discrete

solution also requires additional circuitry for functions including over-

voltage, overcurrent, overtemperature and electrostatic discharge

(ESD) protection. All of this translates to a fairly complex design

process resulting in a higher component count, larger footprint, and

less reliable design solution than a fully-integrated LSI solution.

H-Bridge Driver Topology

Integrated H-bridge drivers are constructed by combining a controller,

output drivers and protection circuits into a single package. The first

H-bridge drivers used bipolar power transistors and bipolar control

circuitry. The bipolar outputs were typically operated in the linear

mode to provide speed control. Simple IC processing made the cir-

cuit practical even though die sizes were large to optimize power dis-

sipation. A limitation of the bipolar output devices was higher power

dissipation, especially in the speed control mode.

The use of power MOSFETs for the output devices was a natural

transition for H-bridge drivers. In addition to the lower losses for a

given voltage rating and smaller die size, voltage-controlled MOS-

FETs are easier to drive than the current-driven bipolar switches,

facilitating efficient PWM control. In addition to higher efficiency,

PWM provides tighter motor speed control as well as faster speed

response. BiCMOS design for the control portion takes advantages of

Controlling DCBrush Motorswith H-Bridge

Driver ICsAdvanced-design integrated circuits combine control and protectionfunctions; offer upgrade path from legacy designs and selection of

control strategies

DC brush motors are increasingly required for a broad range of applications includingrobotics, portable electronics, sporting equipment, appliances, medical devices, automo-tive applications, power tools and many others. The motor itself is a preferred alternativebecause it is simple, reliable and low cost. Equally important, advanced, fully-integrated

“H-bridge” ICs are available to control the motor’s direction, speed and braking.

By Günter Richard, Distribution Sales Director, ROHM Semiconductor GmbH

the strengths of bipolar and CMOS design providing high drive capa-

bility and low power dissipation. A comparison of the power dissipa-

tion characteristics of linear H-Bridge drivers vs. the latest PWM out-

put drivers is shown in Figure 1.

Ongoing improvements in power MOSFETs have increasingly shrunk

the die size to handle a particular voltage and low on-resistance.

Today, control circuitry and the four output drivers are offered in sur-

face mount packages comparable to or only slightly larger than only

one of the output switches required in a discrete implementation. In

summary, the H-bridge driver IC provides a monolithic solution to the

control and output functions required to control the direction and

speed of DC brush motors.

The Ideal H-Bridge Driver

With BiCMOS control and power MOSFET technology, the latest

generation of Rohm devices represent the ideal integrated H-bridge

driver. Figure 2 shows a block diagram of the functional elements. To

handle either analog or digital inputs, the unit provides dual-mode

speed control. VREF provides the analog input. The chip converts

the linear input at VREF into efficient speed control using its internal

PWM conversion circuitry. FIN and RIN are used with a microcon-

troller (MCU) or other digital logic inputs to control direction and

speed.

The control logic takes input from the analog and digital source and

efficiently controls the forward/reverse directions, speed and braking

of the motor by switching the appropriate integrated power MOS-

FETs. Rohm’s P-Channel/N-Channel high-power CMOS output pro-

vides low on-resistance without requiring a charge pump and the

associated external capacitors needed for the N-Channel MOSFETs

in the high side switches common in many integrated H-bridge driv-

ers. Rugged recovery diodes built into the structure eliminate the

need for additional external recovery diodes.

Combined bipolar and CMOS processing in a single chip design

achieves less than 1 ìA current in standby mode. This is an important

consideration for portable, battery-powered applications.

To protect the motor and the driver, protective circuitry includes:

• Overvoltage protection (OVP)

• Undervoltage lockout (UVLO)

• Overcurrent protection (OCP)

• Thermal shutdown (TSD)

• Overlap (shoot-through) protection

• High ESD protection (4 kV)

Figure 1: Comparison of linear vs. PWM implementation. In the linearimplementation, at anything but full speed, the voltage drop acrossthe control transistors results in significant power dissipation.


P R O T E C T I O N

Over and undervoltage circuits keep the IC within its proper voltage

operating range. OCP limits the current draw and essentially shuts

the device down by forcing all driver outputs into a high impedance

state in the event of a short circuit or other excessive current event

such as a locked rotor. TSD protection can provide longer term pro-

tection when the chip is operating within its current capability but

some other fault has occurred, such as an extremely high operating

temperature environment or loss of adequate cooling in an enclosure

or a deteriorated heatsink path. From a timing standpoint, OCP is fast

response protection and TSD is slower. For example, TSD provides

back-up protection for faults that OCP cannot detect such as a soft

short that is within the current limit but still causes an excessive tem-

perature rise. OCP protects the MOSFET outputs and TSD protects

the die. If the die temperature exceeds a predetermined limit, such as

175 ºC, the IC will shut off.

For every H-bridge application, overlap timing circuitry is required to

prevent shoot-through current spikes when switching direction or

applying dynamic breaking. Rohm H-bridge drivers control this inter-

nally. If an MCU is used to directly control the output devices, a pro-

gram must be written to ensure proper timing to avoid shoot-through

problems. A thorough design includes ruggedness to handle unex-

pected occurrences damaging the driver such as ESD. Rohm H-

bridge ICs are specified to handle ESD voltages as high as 4 KV.

PWM Speed Control Techniques Using Rohm H-Bridge Drivers

The latest Rohm H-bridge drivers provide PWM speed control

through a variety of techniques to address the requirements of differ-

ent applications.

MCU Control

With an MCU or other digital logic providing the PWM input, a circuit

like the one in Figure 3 would be appropriate. The pulse train applied

to the FIN and RIN lines controls the direction and the speed digitally

from the MCU. To complete the application, the VREF is tied to VCC

and two external decoupling capacitors are connected from VCC to

motor and IC ground.

Analog Voltage Control

With directional inputs provided through the FIN and RIN pins, the

VREF input can be used to control the DC motor’s speed.

Figure 4 shows a simple voltage divider providing the variable volt-

age source to the internal PWM circuitry. This voltage could also be

supplied from a variable voltage source (potentiometer, resistor array)

that allows for operator control of the motor speed. This design works

best with a regulated power supply. Note: a microcontroller is not

required for this approach; the FIN and RIN inputs could come from

two switches.

Fixed Speed From an Unregulated Supply

With the resistor divider input tied to VCC, if the line voltage changes,

the motor speed will change. A fixed speed can be accurately estab-

lished with a Zener diode in the lower leg of the voltage divider. In

spite of line voltage fluctuations, the motor will be controlled at the

same speed.

Simplified Digital Speed Control

The output of a digital to analog converter (DAC) could drive the

VREF providing the analog control voltage to the driver converting

the signal into a PWM output shown in Figure 5.

Soft-Start Control with Analog Input

The soft-start technique uses a capacitor and two diodes so the volt-

age builds slowly to the full input. The motor starts slow and slowly

reaches its target speed.

Selecting the Right H-Bridge Driver for the Application

Due to the variance of operating voltages, in order to provide the

ideal solution it is important to pick the correct H-bridge driver.

Multiple Voltage and Current Configurations Optimize Perfor-

mance

To meet the requirements of these applications, Rohm offers H-

bridge drivers rated for maximum operating voltages of 7 V, 18 V and


M O T I O N C O N T R O L

Figure 4: Simple analog speed control using a voltage divider input.

Figure 5: With a DAC, a digital voltage converted to analog can pro-vide the VREF input.

Figure 2: The ideal H-bridge driver includes flexibility for analog ordigital operation and extensive protection circuitry.

Figure 3: A digital controller, such as an MCU, can directly drive thecontrol logic circuitry in the H-bridge driver.

36 V with 0.5 A, 1.0 A and 2.0 A current ratings in single and dual

channel packages.

Typically, individual applications have operating voltages ranging

between 3-5 V, 6-15 V or 18-32 V. However each Rohm driver oper-

ates with any VCC below its maximum limit. The lower VCC max

devices provide higher efficiency since the output MOSFETs trade off

higher voltage with higher on-resistance. So selecting the appropriate

VCC max optimizes the power consumption and avoids added

expense for a higher voltage rating.

Low-Profile Packaging

The low-profile Rohm packages are all within 2.2 mm (some as thin

as 1.5 mm), which is especially important in portable products.

Dual-Channel Versions Offer Matched Performance

For applications requiring more than a single independently operated

motor, such as printers, robotics, toys and games, Rohm’s dual-chan-

nel H-bridge drivers offer independent control of each channel in

space saving packages featuring symmetrical pin configuration.

Flexible Control Strategies

Rohm H-bridge drivers provide several options for controlling direc-

tion, speed, brake and idle, as described in detail above. Rohm driv-

ers feature an internal VREF to PWM conversion circuit for simple

analog speed control in addition to digital input control levels of 2.0-

5.0 V TTL from an external MCU.

Migration from Linear Control to PWM

The latest generation of Rohm H-bridge drivers are pin-compatible

with earlier models. Applications using VREF linear control can easily

migrate to the latest design without any modifications to an existing

PCB layout and obtain the advantages of PWM functionality.

Many of these advanced PWM H-bridge drivers are pin compatible

with Rohm’s existing linear output line-up, providing added efficiency

and eliminating the potential for board placement errors.

Putting It All Together

This paper has presented the basics of Hbridge driver technology

and the important benefits of Rohm’s product family including:

• High efficiency

• Minimal external components

• Low power consumption

• Low power dissipation

• Internal shoot-through protection

• ESD protection

• Fast response time

• Built-in fault protection

www.rohm.com/eu

35www.bodospower.com March 2011 Bodo´s Power Systems®www.bodospower.com March 2011 Bodo´s Power Systems®

P R O T E C T I O N

In this article the characteristics of a typical 1.2 kV, 80 mΩ SiC

MOSFET will be discussed. For comparison purposes the following

silicon devices were utilized:

• 1.2 kV, 20 A trench/field stop (TFS)

Si IGBT Fairchild FGA20N120FGD [3]

• 1.2 kV, 20 A non-punch though (NPT)

Si IGBT International Rectifier IRGP20B120U [4]

• 1.2 kV, 0.30 Ω Si MOSFET (Si MOS8) Microsemi APT34M120J [5]

The key to optimal application of the SiC MOSFET requires an

understanding of the device’s unique operating characteristics. The

forward conduction characteristics of the SiC MOSFET along with the

Si MOS8, TFS, and NPT IGBTs are presented in Figure 1.

The relatively high temperature coefficient of RDS(on) for the Si MOS 8

has considerable effect on its conduction losses. At 150 °C, the

RDS(on) of the SiC MOSFET increases only about 20% from 25 °C to

150 °C whereas the Si MOS8 device increases by 250% as shown in

Figure 2. This has a significant effect on system thermal design. For

systems operating in the higher end of their temperature range, the

increase in RDS(on) can be critically important where degradation in

conduction loss must be avoided.

The inductive turn-off losses versus temperature of the SiC MOSFET

compared with the TFS and NPT IGBTs are shown in Figure 3. The

freewheeling diode used with all devices was a 1.2 kV, 10A SiC

Schottky diode. The turn-off losses of the IGBTs are significantly

higher than the SiC MOSFET and strongly increase with tempera-

ture. This is due to the tail loss inherent with IGBTs. The NPT IGBT

is significantly better than the TFS IGBT. However, the NPT IGBT

conduction losses are much higher than the SiC MOSFET. The TFS

H I G H P O W E R S W I T C H


Silicon Carbide MOSFETs Provide Ultimate Energy

Efficiency and Easy Design InThe SiC MOSFET also has significant advantages including simple

drive circuit

The silicon carbide (SiC) MOSFET has unique capabilities that make it a superior switchwhen compared to its silicon counterparts. By nature of its material advantages,

SiC MOSFETs provide lower switching loss, lower on-resistance across its operating temperature range, and superior thermal properties. Furthermore, the SiC MOSFET is

the easiest to use wide bandgap switch presently demonstrated. Best of all, SiC MOSFETs from Cree are now available for commercial use.

By Bob Callanan, SiC Power Applications Manager, Cree, Inc.

Figure 1: Forward conduction characteristics comparison

Figure 2: Normalized RDS(on) vs. temperature

Figure 3: Switching loss vs. temperature comparison (VDD = VCC =800V, ID = IC = 20A, RG = 10Ω)

IGBT conduction loss is lower than the NPT IGBT, but the switching

loss is the highest of the three. In all cases the SiC MOSFET switch-

ing losses are significantly better than its silicon competitors.

To realize the considerable benefits if the SiC MOSFET there are a

few characteristics of the device that need to be understood. The

output characteristics of a typical 1.2 kV, 80 mΩ SiC MOSFET is

shown in Figure 4. The modest amount of transconductance causes

the transition from triode to saturation to be spread over a wider

range of drain current. Therefore, the SiC MOSFET behaves more

like a voltage controlled resistance than a voltage controlled current

source. The lowest RDS(on) is achieved with a +20V gate drive.

The modest transconductance and short-channel effects are impor-

tant to consider when applying the device. SiC MOSFETs need to be

driven with a higher gate voltage swing than what is customary with

Si MOSFETs or IGBTs. The rate of rise of gate voltage will have a

greater effect on the rate of rise of the drain current due to the lower

transconductance.

The recommended gate drive voltage for the SiC MOSFET is 20V.

However, the amount of gate charge required to switch the device is

low. The ramifications of the modestly higher gate voltage and lower

gate charge can be reconciled by using the product of gate charge

and gate voltage as a measure of gate energy. The gate energy

comparison is shown in Figure 5. The results of this comparison

show that the SiC MOSFET gate energy is comparable to or lower

than the other devices. Therefore, the higher voltage swing does not

adversely affect gate drive power requirements.

The gate driver for the SiC MOSFET is simple and uses existing

commercially available components; standard 35V MOSFET/IGBT

gate driver chips are ideal. One recommended line of gate drivers is

available from Clare [6]. The SiC MOSFET does require a modest

amount (-2V to -5V) of negative bias. This is easily accomplished

using very simple techniques. A schematic of a simple gate driver

circuit is shown in Figure 6.



Figure 4: SiC MOSFET forward characteristics (TJ = 150 °C)

Figure 5: Gate energy comparison

To achieve fast switching time, the gate drive interconnections need

to have minimum parasitics, especially inductance. The gate driver

must be located as close as possible to the SiC MOSFET.

In addition to the performance

advantages over competing sili-

con switches, SiC MOSFETs

have distinct advantages when

compared with other SiC switch-

ing devices as well. The com-

peting devices are normally-on

and normally-off SiC junction

field effect transistors (JFETs).

Reported specific on-resistance

of the normally-on SiC JFETs

tends to be the lowest of all SiC

majority carrier switches. However, the device has the inherent

drawback of being normally-on. This causes system complications;

notably lack of a ‘fail-safe’ feature. If the gate bias is lost due to a

failure in the housekeeping supplies, the SiC JFET will be on and

could cause a damaging shoot-through. This can be mitigated with a

SiC JFET – Si MOSFET cascode circuit. In this approach, a low

voltage Si MOSFET is used to switch the JFET source. Being a cas-

code, the MOSFET will conduct full load current and therefore adds

to the overall switch conduction loss partially offsetting the low specif-

ic on-resistance. Providing gate drive for the Si MOSFET and gate

bias for the SiC JFET requires a custom gate driver design.

The normally-off SiC JFET also has very low reported specific on-

resistance. Lowest on-resistance requires the gate junction to be

hard forward biased for the device to operate at its maximum rated

current at normal operating temperatures. The magnitude of the gate

current in this condition is about 200 mA to 1A and must be applied

when the device is conducting. The result is additional system loss-

es on the order of 0.5W to 3W adversely affecting overall system effi-

ciency. Supplying this current requires another custom gate driver

design. Unlike the SiC MOSFET, both normally-on and normally-off

SiC JFETs normalized RDS(on) versus temperature is very similar to a

silicon MOSFET; more than doubling from 25 °C to 150 °C. In most

cases the reported RDS(on) for SiC JFETs are measured at 25 °C

junction temperature. Therefore, the lower specific on-resistance

advantage is lost at routine operating junction temperatures. Lastly,

the vertical SiC JFETs have very limited avalanche capability where-

as the SiC MOSFET has very high avalanche capability [7]. This

makes the SiC MOSFET a very robust switch. A summary of this

comparison is shown in Table 1

Conclusions:

Switches employing wide bandgap materials have significant advan-

tages over their silicon counterparts. The 1.2 kV SiC MOSFET has

definite system advantages over competing Si switching devices.

These advantages include lower conduction loss and lower switching

loss. Of the competing SiC switch architectures, the SiC MOSFET

also has significant advantages including simple drive circuit require-

ments and high avalanche capability. These factors make the SiC

MOSFET a nearly ideal power switch.

References:

[1] Bob Callanan, “Application Considerations for Silicon Carbide

MOSFETs”, Power Electronics Europe, Issue 3, April 2010, pp.

40-43.

[2] R. J. Callanan, A. Agarwal, A. Burk, M. Das, B. Hull, F. Husna, A.

Powell, J. Richmond, Sei-Hyung Ryu, and Q. Zhang, “Recent

Progress in SiC DMOSFETs and JBS Diodes at Cree”, IEEE

Industrial Electronics 34th Annual Conference – IECON 2008, pp

2885 – 2890, 10 – 13 Nov. 2008,

[3] Fairchild FGA20N120FGD Datasheet, Rev A, December 2007

http://www.fairchildsemi.com/ds/FG%2FFGA20N120FTD.pdf

[4] International Rectifier IRGP20B120U-E Datasheet, PD-94117,

3/6/2001 http://www.irf.com/product-

info/datasheets/data/irgp20b120u-e.pdf

[5] Microsemi APT34M120J Datasheet, 050-8088 Rev A, 2-2007

http://www.microsemi.com/datasheets/APT34M120J_A.PDF

[6] http://www.clare.com/Products/IGBT-MOSFETDvr.htm

[7] J. Palmour, Sei-Hyung Ryu, Q. Zhang, L. Cheng, “Silicon Carbide

Switching Devices: Pros and Cons for MOSFETs, JFETs and

BJTs”, Power Electronics Europe, Issue 5, July/August 2009, pp.

19-22.

www.cree.com



Figure 6: Typical gate driver circuit to provide +20/-2V gate pulses

Table 1: SiC Device Comparison

Key Features

��Any Capacitor™ Stable – No Stability Issues withDistributed Capacitance, ESR Changes

��High Delta V Operation Can Eliminate Intermediate IN, 0.8VOUT)

��Fast Transient Response Allows for Smaller, Less Expensive Output Capacitors

��

PartNumber

Input Voltage

Output Voltage

OutputCurrent Package

MIC26400 4.5V to 26V 0.8V to 5.5V 5A MLF®-28LMIC26600 4.5V to 26V 0.8V to 5.5V 7A MLF®-28LMIC26950 4.5V to 26V 0.8V to 5.5V 12A MLF®-28LMIC27600 4.5V to 36V 0.8V to 5.5V 7A MLF®-28L

In today’s power-hungry appl icat ions, there is an insatiable need to deliver high levels of current while maximizing efficiency and minimizing

power density buck regulators are an ideal fit.

The SuperSwitcher II™ integrated FET DC-DC buck regulators are optimized to deliver world class power density coupled with simplicity of use. Ultra-fast transient response, high efficiency, extremely low duty cycle operation and Any Capacitor™ stable are all merged together to make the SuperSwitcher

representative www.micrel.com/ad/superswitcherII.

www.micrel.com© 2011 Micrel, Inc. All rights reserved. Micrel and Innovation Through Technology are registered trademarks of Micrel, Inc. SuperSwitcher II and Any Capacitor are trademarks of Micrel, Inc.MLF is a registered trademark of Amkor Technology.

Power Density AND Performance — Get the

Best of Both Worlds with SuperSwitcher II™

Family of DC-DC Buck Regulators Saves Design Time and Cost

VIN

4.5V to 26V VOUT

1.8V / 12A

VDD

5V

MIC26950

VDD

SGND

VIN

PGND

EN

BST

SW

FBEN

Distributed Power Systems

Servers & Workstations

Industrial Equipment

Applications

40 Bodo´s Power Systems® March 2011 www.bodospower.comBodo´s Power Systems® March 2011 www.bodospower.comBodo´s Power Systems® March 2011 www.bodospower.com

Silicon carbide diodes have been available for some ten years, but

more recently SiC JFETs were introduced and are now manufactured

by at least three companies. SiC JFETs offer closer to the ideal char-

acteristics required for high voltage, high current switching. They are

extremely rugged and can routinely operate at temperatures of

350°C, far beyond the limits of silicon. Other advantages of SiC

JFETs are no saturation voltage, no tail current, low on-resistance, no

body diode and a gentle positive temperature coefficient.

A company at the forefront of SiC JFET development is SemiSouth

Laboratories Inc., based in Starkville, Mississippi. After initially pro-

ducing SiC Schottky diodes, the company commenced manufacturing

SiC JFETs in its own fab in 2008. SemiSouth products are now used

in demanding applications such as downhole compressors, satellite

solar inverters, jet engine control and mil spec power supplies. With

production volumes ramping up, manufacturing costs have come

down and SemiSouth are now ready to move SiC technology beyond

the esoteric into mainstream industrial applications. The extremely

high conversion efficiencies offered by SiC JFETs make the technolo-

gy particularly suited for solar and wind inverters and hybrid/electric

vehicles. These applications require exceptionally high energy effi-

ciency but are also cost sensitive.

The resources available to SemiSouth were strengthened enormous-

ly in October 2010 with the announcement of a partnership with

Power Integrations Inc. (PI), the leading supplier of ICs for ultra effi-

cient IC for power supplies. Together with the technology partnership,

PI has committed to invest $30M to help drive the expansion of pro-

duction facilities at SemiSouth.

3-Phase Power Supply

SiC JFETs now provide the simplest and lowest cost solution for

designing a kW range power supply. This can be demonstrated by

comparing the alternative approaches for a 4kW, 3-phase power sup-

ply. A 1200V SiC JFET implementation will be compared with that

using 600V superjunction MOSFETs, the best available alternative.

Figure 1 shows the two implementations.

Figure 1 shows the two means of implementing a boost input fol-

lowed by a resonant transformer output stage. The circuit is intended

to operate at a nominal 50% duty cycle based around 125 kHz, with

the frequency being varied to regulate the output voltage.

The upper circuit uses two 80mÙ 1200V SiC JFETs. With the input

boosted to 800V, the rms current is ~14A, resulting in a conduction

loss of ~8W in each switch.

The lower circuit uses the best available MOSFET solution. In this

case a dual configuration is required to limit the voltage across the

MOSFETs to 400V. This is because at higher voltage ratings the on-

resistance of the MOSFET would be much higher and the overall

conduction loss requirement could not be achieved.

The MOSFET solution matches the SiC JFET solution in terms of

conduction losses, but at the cost of considerable complexity.


Bodo´s Power Systems® March 2011 www.bodospower.com

The Silicon Carbide JFETin 3 Phase Power SuppliesA technology step for higher efficiency and lower cost

Power supplies in the kW category are used in a huge range of industrial and high relia-bility applications. Much effort has gone into optimizing the efficiency, reliability and costof these power supplies, but advances in recent years have been somewhat incremental. Tomake a significant step forward a change in technology is required. A new semiconductortechnology, now moving into the mainstream is silicon carbide (SiC). SiC now holds the

promise to deliver significant gains on all fronts of efficiency, reliability and cost.

By Nigel Springett, SemiSouth

Figure 1: JFET and MOSFET designs with similar conduction losses

Table 1: Complexity comparison of SiC JFET and MOSFET imple-mentation

SiC JFET MOSFET No. cooled components 5 10 High side drivers 2 6 Current sensing 2 3

www.bodospower.com March 2011www.bodospower.com March 2011

In the case of current sensing, the numbers

alone do not tell the full story (See figure 2)

With the SiC JFET design, the boost current

can be sensed via the 0v line and a simple

current sense resistor can be employed. The

output current must be sensed via a floating

sensor such as a current transformer. How-

ever in the MOSFET design all sensors are

floating, so sense resistors cannot be used.

Therefore two high side sensors (such as

hall effect sensors) and one current trans-

former are required.

In conclusion, although a similar perform-

ance in terms of conduction loss are

achieved using MOSFETs, the additional

complexities render the solution more costly

and potentially less reliable.

Alternatives

There are other alternatives to using 600V

MOSFETs that could be considered. The lat-

est generation of IGBTs offer high current

capability and low conduction loss, but the

switching loss is significant. In the above

design the switching loss at 120 kHz, 600V,

10A would be about 216W! The only way

to bring the switching loss down to 8W

would be to reduce the frequency to

below 20 kHz. At this frequency there

would be problems with audible noise

generation and the inductors would have

to be unacceptably large and heavy.

There are 1000V MOSFETs available

now, which could potentially enable a cir-

cuit as simple as that for the SiC JFET to

be employed. Unfortunately the best

1000V MOSFET available today has a

Rdson of 220mÙ and an output capaci-

tance Coss of 500pf. The result would be

3x the conduction loss and 19W loss due

to the output capacitance. Total losses

would be 50-60W.

The example above is a simplified com-

parison and there are of course other

issues to consider, but the conclusion is

clear. The SiC JFET solution provides

higher efficiency, has half the number of

cooled components and fewer isolated

drivers, requires no high side current

Figure 2: Comparison of sensing

From One Engineer To Another

Find out:www.indium.com/igbt

scan code with mobile device

answers

blogs

tech papers

one-on-one

support

live chat

“ Are you having

difficulty creating a

good lead-free, large

area, planar solder

joint between a DBC

substrate and a base?

We can help.”

[email protected]

Semi-Therm, booth #201

Figure 3: SiC JFET technologies comparison. The SemiSouth trench JFET (right) is a simple,self-aligned, compact design which allows very low on-resistance. (Left: SJDP120R085 ID = f(VDS); Tj = 100 °C ) ( Right: SJEP120R100 ID = f(VDS); Tj = 175 °C)


sense and generates lower EMI. In addition

the SiC JFET design has the flexibility for

either higher power or reduced volume deriv-

atives.

Trench Silicon Carbide Power JFET Tech-

nology

The SemiSouth SiC JFET technology is able

to provide such remarkable performance

because of the vertical channel JFET struc-

ture employed (See Figure 3).

The cell pitch of <4μm employed by Semi-

South yields a die size 5-10 times smaller

than the best equivalent Si MOSFET for the

same voltage rating and delivers significantly

better performance. Figure 4 illustrates the

output characteristics for the SJDP120R085

depletion mode SiC JFET referred to earlier

and the enhancement mode SJEP120R100

which could be used equally as well. Both

products are able to deliver far more than

the 14A RMS required for the 4kW supply,

hence the design flexibility.

The unique design of the vertical channel

JFET structure in combination with precise

control of the variation in device threshold

voltage has allowed for the creation of nor-

mally-on JFETs requiring low negative bias

for blocking as well as truly normally-off

JFETs that require no negative bias for full

blocking. In addition to the 100mÙ device,

SemiSouth produces the 63mÙ

SJEP120R063, a 1200V device capable of

60A output.

SiC JFET technology is now established as

a volume production process with several

manufacturers and has the backing of major

strategic investors such as Power Integra-

tions (NASDAQ: POWI) and Schneider Elec-

tric. The technology offers unequalled capa-

bilities for extremely demanding hi-rel appli-

cations and provides the highest power con-

version efficiencies possible for sensitive

requirements such as solar power. The tech-

nology is now ready for the mainstream

industrial market. The designers of industrial

power supplies could do well to seriously

consider using SiC JFETs, or risk being side-

lined by their competitors.

www.semisouth.com


Figure 4: SiC JFET Typical Output Characteristics

International fair forthe use of renewableenergy sources

The biggest small wind

turbine show in Europe!

LDO as a ripple filter

It is common practice amongst power electronics engineers to use an

LDO as the last stage of a power-distribution tree. Figure 1 shows

the basic concept of a ripple filter. In stage one, the switching regula-

tor generates an intermediate voltage (VINTERMEDIATE) from the

input voltage of the system supply VIN. In stage two, the LDO regula-

tor generates the system output voltage VLDO from VINTERMEDIATE.

The goal is to achieve high power-conversion efficiency in stage one

and to remove switching noise in stage two.

The most important factor for minimizing the switching noise at stage

two is the power supply ripple rejection (PSRR). PSRR, a measure of

how small the ripple at the output is compared to the input ripple1,

typically is measured in decibels using the PSRR calculation in Equa-

tion 1:

Equation 1

PSRR is a well-known term within power electronics and there are

many LDO devices in the market considered to be high PSRR. This

article explains why most of the high PSRR LDOs do not perform

well for this type of application.

Understanding a PSRR graph

Figure 2 shows the PSRR of a traditional high PSRR LDO with

PSRR peaking at 75 dB somewhere between 600 – 700 Hz. This

value is sufficient to make this a high PSRR LDO, but it is the PSRR

at the power supply’s switching frequency that is important. For

example, the switching frequency of recent switching regulators is

between 300 kHz to 6 MHz. Unfortunately, the high-frequency noise

is outside the bandwidth of most typical high PSRR regulators, so the

LDO response time is too slow to effectively filter out the switching

noise.

In Figure 2, the PSRR curve consists of three regions. The first

region is the frequency range from 10 Hz to 1 kHz where the PSRR

is high and relatively flat. The second is the frequency range from 1

kHz to 110 kHz where the PSRR decreases steadily. The third is all

frequencies higher than 110 kHz where the PSRR increases again.

The first and second regions represent the effective PSRR band-

width, meaning this traditional high PSRR LDO has 110 kHz of effec-

tive PSRR bandwidth. In the third region PSRR increases due to the

output capacitor’s impedance, parasitic board impedance, and capac-

itor itself, while the LDO contributes nothing to PSRR in this region.

P O W E R S U P P LY


Wide Bandwidth PSRR of LDOsAnalog-to-digital converters or digital-to-analog converters

require a clean power supply to operate accurately

As the switch-mode regulator is improving its position as a solution with good power-conversion efficiency, the low dropout (LDO) regulator is shifting its focus to high

performance rather than conversion efficiency. Because the LDO is not a switch-modedevice, it is free of switching noise and is being recognized as a secondary filter forswitching noise to improve performance in noise-sensitive applications. This article

explains key LDO requirements to effectively minimize power supply ripple voltage bycomparing a traditional LDO and a wide-bandwidth power supply ripple rejection

(PSRR) LDO.

By Masashi Nogawa and Kyle L. Van Renterghem, Texas Instruments

Figure 1: LDO as a ripple filter

Figure 2: PSRR curve of a traditional high PSRR LDO

Figure 3 (A) is a simplified diagram of a LDO, which consists of: Tr1,

or a pass transistor; R1, which is a feedback resistor; R2, an output

capacitor (COUT) with its RESR or equivalent series resistance (ESR);

and RLOAD, or the load resistance. To think about PSRR, Figure 3 (A)

can be grouped into two parts: Z1 and Z2. PSRR is just a ratio of Z1

and Z2 (Equation 2).

Equation 2

In the first PSRR region the error amplifier has a large amount of

gain. Thus, Z1 is well controlled, which results in a high PSRR value.

At the boundary of regions one and two, the gain of the amplifier

starts to roll off, typically by 20 dB/dec. The lower gain reduces the

loop’s sensitivity to changes in the output voltage, causing imped-

ance of the pass device to adjust less quickly to any incoming

changes; thus, decreasing the device’s PSRR in region two.

As the frequency increases the impedance of the output capacitor

decreases, causing more of the ripple to be attenuated across the

output device – which increases the PSRR of the LDO in region

three. At the boundary of the second and third regions, the imped-

ance of Z2 decreases to the point that the majority of the signal is

being shorted across the capacitor instead of being actively attenuat-

ed by the LDO. Once the LDO is not significantly contributing to the

PSRR, the pass transistor can be treated as a simple resistor, which

only attenuates the ripple passively. Figure 3 (B) represents this situ-

ation.

Figure 4 shows the PSRR, which could be expected by using ideal

passive components shown in Figure 3 (B). This was calculated

using values typically found in real IC evaluation. In this article,

RMOS is calculated by using Equation 3:

Equation 3

This curve is very similar to the third region of PSRR shown in

Figure 2. Here Figure 3 (B) is a good conceptual representation

of the LDO in this region.

Wide-bandwidth high PSRR LDO

Some high-performance LDOs, such as the TPS7A8001, have been

designed to address this high-frequency PSRR need (see Figure 5).

Instead of having very high PSRR in the low-frequency region, a

wide-bandwidth high PSRR LDO should have relatively high PSRR

over the frequency range of recent switching regulator designs, typi-

cally between 300 kHz to 6 MHz. In Figure 3, the effective PSRR

bandwidth (first and second regions) of the wide-bandwidth high

PSRR LDO is 1 MHz.

www.bodospower.com

Figure 3: Simple diagram for PSRR

Register online and use

the loyalty discount!

International Conference and Exhibition on Hydrogen,Fuel Cells and Electric Drives

Hamburg, Germany

8 – 9 June 2011Hamburg Messe

www.h2expo.com

Design Toolsfor engineers and developers

� www.we-online.com/toolbox� One source – plenty of R&D support tools� Free of charge & offline processable� Spice simulator� Component libraries� IC reference design search� Application notes

www.we-online.com

VINTERMEDIATE and VLDO spectrum comparison

Figures 6 – 7 illustrate the effect wide-bandwidth PSRR has on high-

frequency input noise. Note that these graphs are the spectrums of

VINTERMEDIATE, which is the same in both graphs, and VLDO. These

are direct conversions from Fourier transforms, which are not spec-

trum density graphs, used widely to express noise performance. In

Figure 6, a traditional buck switching regulator (voltage-mode and

step-down) is connected to the traditional high PSRR LDO regulator.

In Figure 7, the same switching regulator is connected to the wide-

bandwidth high PSRR LDO.

The largest VINTERMEDIATE peak is at the switching frequency, which

is 285 kHz. The VINTERMEDIATE curve also contains the switching fre-

quency’s harmonics and a major sub-harmonic. At 285 kHz the peak

measures –43 dBV, which is equivalent to 40 mVpp of ripple (Equa-

tion 4).

Equation 4

Comparing Figures 6 – 7, a wide-bandwidth high PSRR LDO reduces

the ripple from VINTERMEDIATE better than the traditional high PSRR

LDO. At the sub-harmonic frequency of 143 kHz, the traditional high

PSRR LDO passes most of the peak from the input to the output

because it has practically no PSRR at 285 kHz (Figure 2).

VINTERMEDIATE and VLDO time domain waveform comparison

In time domain, Figures 8 – 9 confirm the voltage attenuation, shown

earlier. These figures compare the time domain waveforms of

VINTERMEDIATE and VLDO. They show that VINTERMEDIATE, which is the

same for both graphs, is a sinusoidal waveform of approximately

40 mVpp, which matches the calculation made using Equation 2.

The frequency is around 285 kHz, which matches the switching

regulator’s operation frequency.

The traditional high PSRR LDO shows a significant sinusoidal wave-

form on the output that corresponds in frequency to the input wave-

form (Figure 8). The remaining ripple on VLDO will be seen by all

devices using it as a power rail and could affect their performance. In



Figure 7: Spectrum of a wide-bandwidth high PSRR LDO

Figure 8: Time domain waveform of a traditional high PSRR LDO

Figure 6: Spectrum of a traditional high PSRR LDO

Figure 5: PSRR curve of a wide-bandwidth high PSRR LDO

Figure 4: PSRR from Figure 3(b)

comparison, the wide-bandwidth high PSRR LDO’s output is almost

flat (Figure 9). This provides a much cleaner power rail for all devices

connected to it.

For example, analog-to-digital converters (ADC) or digital-to-analog

converters (DAC) require a clean power supply to operate accurately

and are designed with some PSRR for this purpose. Radio frequency

(RF) applications also are very sensitive to their power supply

because any ripple on the power rail causes AM and FM effects on

the output radio signal. By minimizing ripple of the power supply, the

overall performance of the application can be improved.

Conclusion

When using an LDO as a secondary filter, remember that it’s not only

the absolute maximum PSRR that is important. While designing an

LDO post regulator, pay spe-

cial attention to the PSRR at

the power supply’s switching

frequency. For applications

sensitive to high-frequency

noise, a wide-bandwidth high

PSRR LDO, like the

TPS7A8001, is more effective

than a traditional high PSRR

LDO.

References

Pithadia, S., & Lester, S., LDO

PSRR Measurement Simpli-

fied,

July 27, 2009, Texas Instru-

ments.

Teel, J., Understanding power

supply ripple rejection in lin-

ear

regulators, August 5, 2005,

Texas Instruments.

Download a datasheet for the

TPS7A8001 here:

www.ti.com/tps7A8001-ca.

Learn more about LDO’s from

TI here: www.ti.com/ldo-ca.

www.ti.com



Figure 9: Wide-bandwidth high PSRR LDO time domain waveform

Power Your Recognition InstantlyBased in Munich, Germany, ITPR Information-Travels Public Relations is a full-service consultancy

with over a decade of experience in the electronics sector.

As a small exclusive agency, we offer extremely high ROI,

no-nonsense flexibility and highest priority to only a handful of companies.

Strategical SupportCorporate/Product Positioning, Market/Competitive Analysis, PR Programs, Roadmaps,

Media Training, Business Development, Partnerships, Channel Marketing, Online Marketing

Tactical PRWriting: Press Releases, Feature Articles, Commentaries, Case Studies, White Papers

Organizing: Media Briefings, Road Shows, Product Placements in Reviews and Market Overviews,

Exhibitions, Press Conferences

Monitoring and Research: Speaking Opportunities, Editorial Calendars, Feature Placement,

Media Coverage, Competitive Analysis

Translations: Releases, By-Lined Articles, Websites, etc.

Call or contact us today for a free consultation on how PR

can dramatically affect your company’s bottom line.

ITPR Information-Travels Public Relations

Stefanusstrasse 6a, 82166 Gräfelfing-Munich, Germany

Tel ++49 (89) 898687-20, Fax ++49 (89) 898687-21,

[email protected]

w w w . i n f o r m a t i o n - t r a v e l s . c o m


Conventional Technologies

At present, of course, DC-DC converters employ existing technologi-

cal designs, one fundamental aspect of which is, for example, topolo-

gy. DC-DC converters employ many different topologies, none of

which is superior to all others in every respect. Some applications

have requirements that are best satisfied by a specific topology.

Although full consideration of the large number of topologies avail-

able could be a daunting task, it is helpful to consider the advantages

and disadvantages of the two main topological classes: fixed fre-

quency pulse width modulation (PWM) and variable frequency quasi-

resonant zero current switching (ZCS).

Of the two, PWM can be somewhat simpler in design, but it inherent-

ly trades off efficiency against operating frequency, both important

parameters for electric vehicles (EV) or hybrids (HEV).

High-frequency operation has long been recognized as one of the

main keys to achieving high-power density ⎯ e.g., smaller magnet-

ics, filters, and capacitors ⎯ in switch mode converters. With fixed-

frequency switchmode converters, however, switching losses

increase directly with operating frequency, resulting in the right place

which limits achievable power density. Variable-frequency converters

overcome the frequency barrier by having each turn-on and turn-off

of the switch occur at zero current.

A second major difference between fixed frequency and variable fre-

quency DC-DC converters is the noise ⎯ again, an important param-

eter for EVs/HEVs ⎯ generated by the switch. The hard switching of

the PWM generates more noise than the soft switching of ZCS.

Today, the primary EV/HEV DC-DC converter application is the con-

version from a high voltage battery down to the 12-volt typical car

voltage, although higher voltages, such as 42 Volts for power steer-

ing, may be required. DC-DC converters ⎯ generally customized ⎯used in this application typically have inputs of 250 – 450 Volts,

adjustable outputs of 12,5 to 15,5 Volts, and output powers from 250

W to 3.5 kW. The sizes and weights of available DC-DC converters

vary substantially, dependent on the operating frequency, of course,

but also to some extent on the inputs and outputs of voltage and

power.

With conventional topologies, efficiencies are typically mid-80-90%,

but the low line efficiencies are likely to be perhaps four or five per-

centage points lower. As a result, AC-DC and some wide-range DC-

DC products need to be derated at the low line.

High-voltage/high-power conversion in vehicles is in an early stage.

Many technical and economic challenges must be solved for EV and

HEV applications. The technical challenges for such a converter

⎯ many of them interrelated ⎯ include size, weight, efficiency, elec-

tromagnetic compatibility/ electromagnetic interference (EMC/EMI),

reliability, high-voltage isolation, heat removal/ thermal management,

and, cost. In addition, of course, reliable performance in the environ-

ments of heat, cold, shock, and vibration of a road vehicle is a given.

Advanced Technologies

DC-DC converters for future EVs and HEVs require high power den-

sity, efficiency, and scalability that cannot be cost-effectively support-

ed by low frequency, bulk converter designs. While a 2 kW DC-DC

converter may be a common design target, high-end vehicles require

more power, whereas smaller DC-DC converters with lower power

ratings would provide lower cost for entry-level EVs and HEVs. To

cope with this breadth of power needs, a flexible, scalable power sys-

tem methodology using high-power density, modular converters

capable of efficient bus conversion, isolation and voltage regulation

will enable greater performance and faster time-to-market, cost-effec-

tively.

Such advanced technologies are available or coming on line now.

These power conversion engines can support efficient high-voltage

electric power distribution within vehicles and provide key advantages

to the power system designer, including small size, low weight, high

power density, high efficiency, design flexibility, and fast response to

changing electrical demands.

D C / D C C O N V E R T E R

DC-DC Converter Technologies forElectric/Hybrid Electric Vehicles

DC-DC converters employ many different topologies

Electric cars outsold those with internal combustion engines (ICE) in the early 1900s buttwenty years later, they had all but disappeared. Now, in response to high gas prices andmandated emission and fuel performance standards, they’re coming back. Some of themare manufactured by automakers and some are conversions from an ICE car to electricvehicles, but in any vehicle with a higher battery voltage than traditional vehicles, DC-

DC conversion is an integral part of automotive power electronics.

By Keith Nardone, Director, Business Development and Tom Curatolo, Director, Applications Engineering, Vicor Corporation

Specifically, new power conversion technologies ⎯ in the form of

DC-DC power conversion engines ⎯ that promise advanced solu-

tions for EV/HEV vehicles include:

Zero-Voltage Switching (DC/ZVS) DC-DC converters with 95%

efficiency at 1 kW/in3 power density;

ZVS Buck-Boost regulators with > 97% efficiency at 1 kW/in3; and

Sine Amplitude Converter™ High Voltage (SAC HV) bus converters

with 97% efficiency at 1 kW/in3.

DC/ZVS DC-DC Converters

Double clamp zero voltage switching (DC/ZVS) converters (Figure 1)

have the capability of providing a regulated output from a very wide

input range. Adaptive cell power systems involve a multiplicity of

converters that are configured in an array to provide wide-range,

high-voltage, high-frequency power processing. A converter block

typically utilizes two magnetically coupled converter cells that are

selectively configured in series or parallel (Figure 2).

In either configuration, common-mode noise is essentially cancelled,

eliminating a major filtering challenge for EVs and HEVs.

Adaptive cell topologies embodied in DC/ZVS DC-DC converters for

EV/HEV DC-DC converter performance may include Sine Amplitude

Converter (SAC) cells. SAC engines utilize zero-voltage/zero-current

switching to eliminate switching losses. By eliminating switching loss,

the SAC can be operated efficiently at relatively high frequencies,

typically in the MHz range, resulting in smaller product size. High

operating frequency allows for miniaturization of many components,

increasing overall converter power density. Soft switching converters

operating at high frequency also minimize electromagnetic interfer-

ence (EMI) and the filtering components required by hard-switching

converters operating at low frequency.

www.bodospower.com

Figure 1: DC/ZVS Converters are available in standard chip and brickpackages.

Figure 2: The DC/ZVS platform provides flexibility and redundancy,but, more important, it provides high efficiency over the whole range

MAKING MODERN LIVING POSSIBLE

DANFOSS SILICON POWER

SILICONPOWER.DANFOSS.COM

The future of cool designMove into the fast lane with customized

power modules

It cannot be stressed enough:Efficient cooling is the most important feature in power modules. Danfoss Silicon Power’s cutting-edgeShowerPower® solution is designed to secure an even cooling across base plates. In addition, our modules can be customized to meet your automotive requirements in detail, offering: Low weight, compact design, extended life and very low life cycle costs In short, when you choose Danfoss Silicon Power as yoursupplier you choose a thoroughly tested solution with unsurpassed power density. Day in and day out. Please go to siliconpower.danfoss.com for more information.

ShowerPower®

50

The SAC engine is typically used to provide fixed voltage ratio bus

conversion with HV isolation. The DC-ZVS engine provides DC-DC

conversion with regulation and isolation. Figures 3 and 4 show effi-

ciency and output ripple performance for DC/ZVS converters config-

ured in a multi-kW array.

ZVS Buck-Boost Regulators

ZVS buck-boost regulators provide a regulated output from an unreg-

ulated input source. ZVS buck-boost regulators may be used stand-

alone, as non-isolated voltage regulators, or combined with SAC cur-

rent multipliers to create isolated DC-DC converters. The regulator

may be “factorized” away from SAC current multipliers to provide

increased density at the point of load while supporting efficient power

distribution and savings in conductor weight and cost. In combination,

these engines enable DC-DC converter systems with significantly

higher density, flexibility, and efficiency than conventional converters.

ZVS buck-boost regulator capabilities include:

• Input and output voltages up to 650 Vdc

• Up to 5:1 input voltage range

• Up to 5:1 voltage step-up / step-down ratio

• Conversion efficiency up to 98%

• Scalable from hundreds of Watts to kiloWatts.

A unique soft switching topology and ZVS control architecture enable

efficient HV operation at 1 MHz. Regulators may be paralleled to

achieve increased output power. A feature of the regulator control

D C / D C C O N V E R T E R

Figure 3: Efficiency vs. input line and output load of a 2.8 kW array ofDC/ ZVS cells including input and output filtering; Vout is 48 Vdc.

Figure 4: Output ripple of a 2.8 kW DC-DC converter array of DC/ZVS cells including input and output filtering; Vout is 48 Vdc.

www.apec-conf.orgwww.apec-conf.org

2011March 6–10, 2011

Ft. Worth, Texas

THE PREMIER

GLOBAL EVENT

IN POWER

ELECTRONICSTM

THE PREMIER

GLOBAL EVENT

IN POWER

ELECTRONICSTM

SPONSORED BY

Visit the Apec 2011

web site for the latest

information!

architecture is that its switching sequence does

not change in either buck or boost mode ⎯only the relative duration of phases within each

operating cycle are controlled to effect voltage

step up or step down.

SAC HV bus converters

Fixed-ratio converters, which include the SAC

HV bus converter, are capable of efficient HV

bus conversion. Additional capabilities include:

• Input and output voltages up to 650Vdc

• Up to 5:1 input voltage range;

• Current multiplication up to 200X;

• Conversion efficiency up to 98%

• Scalable from hundreds of Watts to kilo-

Watts.

ZVS-ZCS Sine Amplitude Converter topologies

with a low Q power train support efficient high-

frequency power processing with a fixed-fre-

quency oscillator having a high spectral purity

and common-mode symmetry, resulting in

essentially noise-free operation. The control

architecture locks the operating frequency to

the power train resonant frequency, optimizing

efficiency and minimizing output impedance.

By effectively canceling reactive components,

output impedance, Zout, can be relatively low.

To further reduce Zout, or for greater power

capability, bus converters can be paralleled

with accurate current sharing. Quiet and pow-

erful, SAC bus converters provide essentially

linear voltage / current conversion with flat out-

put impedance up to about 1 MHz

In combination, these power technologies

promise superior solutions to the technical

challenges associated with EVs and HEVs

including small size, low weight, very high effi-

ciency, low EMI, high-voltage isolation, heat

management, modularity, design flexibility,

scalability, and cost. They are easily paralleled

to configure fault-tolerant high-power arrays.

www.vicorpower.com

cui.com/power

Smarter ¬ Auto compensation¬ Dynamically adjustable¬ System intelligence

Faster ¬ Greatly reduce your design cycle

Smaller¬ Reduced footprint: 12 A - 0.50" x 0.925" 25 A - 0.50" x 1.075"

smarter, faster, smaller

Check out the latest addition to CUI’s power line: Novum digital dc-dc power POL modules

At CUI, our approach is to develop smarter, faster, smaller power modules. Whether it’s an embedded ac-dc power supply, a board level dc-dc converter, or a level V external adapter, we continuously strive to keep our power line, that ranges from 0.25 W to 2400 W, ahead of the curve.

NDM1-250

NDM1-120

With high-quality components from Toshiba inside your products you can actually improve theconsumer experience.

Our newly upgraded display microcontrollers with 32-bit ARM processor have been designedto simplify all industrial, home-appliance, consumer and multimedia applications, enabling a

more reliable and cost effective human-machine-interface experience that is perfectly in tunewith today.

Discover how Toshiba could help improve your product with easy and straightforward prototyping.

Visit us today at www.toshiba-components.com/microcontroller

FOR THE MOST REWARDINGCUSTOMER EXPERIENCE, YOU HAD

BETTER START ON THE INSIDE.


When selecting a smart meter, design and

value for money are of paramount impor-

tance. Other complex issues, such as geo-

graphical implementation and restricting

timescales may tempt you to just pick a solu-

tion from a long-standing and reputable

meter manufacturer. With the roll out of elec-

tricity meters and gas hot on its heels, sim-

ply selecting a ‘safe’ design can be detri-

mental to longer-term goals and the wrong

choice can prove an expensive mistake.

The term “smart meter” has been used

(often incorrectly) to represent a variety of

products on a spectrum ranging from a

dumb meter with a radio attached for remote

reading, to a high-tech, high-cost meter with

multiple 2-way communications interfaces,

supporting every conceivable measurement

and tariff option, many of which may not be

considered necessary today. Off-the-shelf

meters may sound like a quick and straight-

forward option, but inevitably incumbent

meter manufacturers have been forced to

make many compromises in the design in

order to make a product that could be used

by a wide range of utilities. A good analogy

would be buying a computer made to your

specifications from a bespoke manufacturer

like Dell, rather than picking up a ready-

made one from a high street retailer. The

price would be fairly similar, but the features

are tailored to meet your needs, such as a

high speed graphics card for gaming or extra

memory for image storage.

Demands on the applications of a smart

meter will increase as other technology

develops. As such, meters rolled out in the

next few years must have the ability to adapt

to changes in application that may happen in

ten years’ time, or utilities will find them-

selves with meters that need to be complete-

ly replaced every few years just to keep up.

Utilities investing in smart meters need to

take into account the advances made in

metrology methodology, production methods

and materials, communications technologies,

electronic components, firmware and operat-

ing systems. For utilities without internal

knowledge in this area, the best approach

may be to work with an experienced technol-

ogy development partner to provide the tech-

nical insight. Utilities should make sure that

the partners they select to help them devel-

op their smart meters have enough specialist

knowledge to be able to predict applications

that may become necessary in future and

future proof the meter accordingly.

It is important to remember that different utili-

ties and countries will have different IT sys-

tems in place, radically different geogra-

phies, population densities and housing

stocks, a variety of communication require-

ments, and different distribution infrastruc-

tures. So instead of looking at what’s avail-

able now, each utility should be thinking

about what are the essential and desirable

requirements for their smart meters and con-

sidering a bespoke solution to meet these

requirements.

Specification questions

Some of the more obvious specifications

relate to, for example, the quantities to be

measured and their accuracy limits, the time-

of-use tariff structure, and minimum frequen-

cy and reliability of remote reading.

The harder ones relate to ill-defined and

evolving requirements – for example:

• Will it need to be paired with a home ener-

gy monitor, to help engage customers,

and what sort of depth and resolution of

data will this require?

• What communications means and proto-

cols will it need to support out of the box,

and in the future? Does it need to commu-

nicate with other smart meters – maybe

an electricity meter that’s already installed,

or perhaps one that might be installed

later?

• What types of smart grid functionality will

be needed in future – load shedding or

time shifting of smart appliances, or con-

trol of the charging of electric vehicles?

• How will it integrate with future distributed

local generation and manage future feed-

in tariff changes?

• It’s hard to predict and build in all these

diverse requirements today, so which

hooks and features for adding them in

remotely do we need to include?

A clear understanding of objectives should

lead to a finished product that will provide

the highest ROI for the utility and strong

benefits for consumers. In many cases a

bespoke design will provide the best balance

between cost and functionality for the meter,

and if executed proficiently, will also confer a

number of extra benefits such as in-field

upgradability, ownership of the design, flexi-

bility of manufacture and supply chain con-

trol.

One of the key ways to build for the future is

to specify a meter with a larger flash memo-

ry capacity – this provides the ability to store

firmware images for upgrade purposes, and

M E A S U R E M E N T

Getting the Best Value SmartMeter for Your Money

Demands on the applications of a smart meter will increase

Utilities and governments must think ahead when planning a smart meter rollout – early obsolescence is an expensive error. Customise and build in future-proofing to stay

ahead of the game.

By Mark England, CEO, Sentec

Figure 1: iConA smart elec meter

to record rich, deep data to support future

applications such as usage profiling and load

disaggregation, for almost no additional cost.

Using industry standard processor architec-

tures and hardware interfaces between func-

tional blocks means that, as new improved

versions of devices become available from

different manufacturers, it is relatively easy

to update the design to take advantage of

them, and mitigate the risk of component

obsolescence. Considering the capability to

deliver additional functionality, even if not

implemented in the initial firmware, is also

likely to extend the useful life of the meter.

Traditional meter manufacturers have built

their businesses and manufacturing up

around the model of a steady ongoing

replacement of product as it reaches the end

of its working life. The new waves of smart

meter deployment require much larger vol-

umes of meters to be delivered over short

periods of time, something that not all tradi-

tional manufacturers have been prepared

for. This has been evident in North America,

where the current rate of electricity meter

installations is approximately five times high-

er than the historical replacement rate. This

rapid fluctuation of the supply volume is very

familiar to the world of consumer electronics,

where products are typically manufactured in

high volume by contract manufacturers for

relatively short production runs. Capacity

can be scaled up and down relatively quick-

ly, and at multiple plants if needed. At the

end of the product design life, or a particular

wave of installation, the contract manufactur-

er simply reassigns the production facilities

to build different products. By contrast, tradi-

tional meter manufacturers who have invest-

ed in their own capital-intensive production

facilities may struggle to meet these peaks

in demand, and have to carry the cost of the

line and employees when orders are low –

these costs all have to be passed onto the

utility as part of the product price, and might

affect the cost or payback of the rollout

because it is extended over a longer period.

For utilities specifying meter design, the abil-

ity for the finished product to be built by a

contract equipment manufacturer (CEM) is

an important part of the design challenge.

This ranges from taking advantage of the

tremendous buying power of the CEM by

using components widely used in other high

volume products, making best use of the

CEM’s PCB manufacturing and test capabili-

ties, designing out steps or processes with

high capital equipment or fixturing costs,

using commonly available materials and

processes wherever possible, and avoiding

single-sourced or long lead-time parts.

Decisions made by utilities now, and how

they choose to spend their money, will have

a big impact on the success of smart meter

roll outs and how consumers perceive the

technology in the future. Utilities are in a

position to decide on the requirements for

their meter, and produce the exact instru-

ment they need, and ensure it will be a valu-

able asset for a suitably long period. It is

well worth investing up front to provide the

best ROI for the rollout.

Commissioning a bespoke design means the

resulting product can provide a truly smart

meter with much more potential than existing

offerings. Above all else, it will match the

specific utility requirements, and provide a

longevity and upgradeability unrivalled by

off-the-shelf products. It is this upgradeability

that will be key to ensuring the consumer

engagement required to make the project a

success. The future is in our hands – it’s cru-

cial that we make the right choices.

Bespoke meter design in the field

OnStream’s smart electric meter has been

designed using Sentec’s Mobius sensor,

GSM communications and large memory

capacity to enable future applications to be

added. Furthermore the upgrades can be

added remotely.

These meters are currently being rolled out

in trials with utilities in the UK.

OnStream has taken a long term strategic

view and believes it is “critical to create a

product that is perfectly suited to the region”.

The bespoke approach was deemed the

most cost-effective way to achieve such a

product.

www.sentec.com

www.bodospower.com March 2011

Figure 2: OnStream smart electricity meter

��

��

�� !"#$

�� %��&�'��(�)��*+

�� ,�� '!�"��!-&&&�./,

�� .�� 0�� $��1��

��'!�"��(&�� 0� �� +�� (&

��!-&&&�� $��2�� 3�� +� ��

4$��$�� 5��

,� �� 6�� 7%4��

,�� 8� ��+��9

:;��$�� ;�� ,��


N E W P R O D U C T S

Avago Technologies announced precision

optical isolation amplifiers for motor control

and current sensing applications. The ACPL-

790B, ACPL-790A and ACPL-7900 devices

improve the accuracy and response times of

the Avago isolation amplifier portfolio, while

addressing compact applications with a

smaller footprint package design. The high-

precision isolation amplifiers are ideal for

current and voltage sensing in AC and

brushless DC motor drives, industrial invert-

ers, servo motor drives, wind power genera-

tion, solar panel power systems and general

analog isolation.

As current flows through the external resistor

in a motor drive implementation, the result-

ing analog voltage drop is sensed by an

ACPL-790B/790A/7900 isolation amplifier,

and it allows a proportional output voltage to

safely be created on the other side of the

optical isolation barrier. Competing solutions

based on Hall Effect technology and current

transformer technology suffer electrical

parameter variation over temperature fluctu-

ations and require a larger footprint in a

design. The ACPL-790B precise isolation

amplifier provides up to 0.5percent high gain

accuracy, and offer 200 kHz bandwidth and

1.6 μs fast response time to enable capture

of transient signals in short circuit and over-

load conditions. The devices operate from a

single 5V supply that is compatible with 3.3V

outputs. This performance is delivered in a

compact DIP-8 package that is suitable for

automated assembly and meets worldwide

regulatory safety standards.

www.avagotech.com

Isolation Amplifiers with Increased Accuracy for Motor Drivers

Nextreme Thermal Solutions introduces the

OptoCooler HV37 module, the next product

in its high-voltage (HV) line of thin-film ther-

moelectric coolers (TECs) designed to

address photonics cooling applications with

larger heat pumping requirements. At 85°C,

the OptoCooler HV37 can pump 4.5 watts or

107W/cm2 of heat in footprint of only 6

mm2. The device is only 0.6mm high, mak-

ing it one of the thinnest heat-pumping TECs

in the photonics market today.

At 85°C, the OptoCooler HV37 can create a

temperature differential (deltaT) of up to

60°C between its hot and cold sides, and

operates at a maximum voltage of 7.7V,

making it compatible with commonly found

board-level currents and voltages. At 25°C,

the device can create a deltaT of up to 50°C

with a maximum voltage of 5.9V.

The OptoCooler HV37 is RoHS-compliant

and is manufactured using gold-tin (AuSn)

solder, which enables assembly tempera-

tures as high as 320°C. These assembly

temperatures make the HV37 module com-

patible with industry standard processes for

packaging photonics devices that require

tight tolerances.

www.nextreme.com/optocooler

OptoCooler HV37 Thermoelectric Module for Photonics Cooling

Power Integrations announced seven new members of its popular

LinkSwitch-PH family of LED driver ICs. Optimized for industrial and

commercial settings where high efficiency and system longevity are

dominant requirements, the new devices (LNK413-LNK419) are suit-

able for lighting applications ranging from 3 W bulbs to 55 W replace-

ments for fluorescent lighting fixtures. The devices, which can

achieve up to 88% efficiency, feature a PWM-dimmable single-stage

controller with both power factor correction (PFC) and accurate con-

stant current (CC) power conversion functionality. The integrated

PFC and CC functions allow multiple drivers to be connected in par-

allel to drive exterior and street area lights efficiently and with func-

tional redundancy.

LinkSwitch-PH devices incorporate the PFC/CC controller, a 725 V

MOSFET and MOSFET driver into a single package, which simplifies

layout and design and eliminates parasitic elements between the

controller and MOSFET. The new ICs enable the ultimate in high reli-

ability at low cost by eliminating up to 25 additional components used

in traditional isolated flyback designs, including the high-voltage elec-

trolytic bulk capacitor and the optocoupler – the components most

likely to limit the lifetime of an LED lamp.

David New, lighting product marketing manager at Power Integra-

tions, said: “These additions to the LinkSwitch-PH range complement

the existing family of TRIAC-dimmable devices. Optimized for high

efficiency in simple flyback designs and operating at input voltages

up to 305 VAC, they enable the development of both single-voltage

and universal-input products suitable for industrial and commercial

lighting applications. Designers using these devices in solid-state

lighting applications can expect the operational life of the driver to

match that of its accurately controlled LED array.”

www.powerint.com/linkswitch-ph

LinkSwitchTM-PH Family of LED Driver ICs


Maxim introduces the MAX5977, a

hot-swap controller for 1V to 16V

backplanes. This device features an

integrated current-sense amplifier

that provides a 1% accurate current

output over a 10mV to 50mV input

voltage range. This allows system

designers to precisely

monitor/measure load current in

high-availability systems. A calibra-

tion mode allows the current-sense

amplifier to be fine-tuned for pro-

duction testing of the design. The

MAX5977 is well suited for network-

ing, base station, storage, and com-

puter server line cards requiring

high reliability and precision current

monitoring.

The MAX5977 allows line cards to be safely inserted

and removed from a live backplane without causing

glitches on the system power-supply rail. It is rated

for 1V to 16V input and can withstand transients or

inductive spikes up to 28V. An integrated charge

pump drives a low-cost, external n-channel MOSFET.

VariableSpeed/BiLevel(TM) fault protection improves

system reliability by quickly responding to overcurrent

and short-circuit conditions, while preventing nui-

sance trips caused by noise or transient conditions.

The MAX5977A latches off after a fault condition,

while the MAX5977B automatically restarts. Other

features include: programmable undervoltage and

overvoltage protection, an active-high power-good

(open-drain) output, and an active-low (open-drain)

fault output.

www.maxim-ic.com

1V to 16V Hot-Swap IC with Precision

Current-Sense Output

Saving space and reducing bill of material compo-

nents are always on the minds of design engineers,

especially in LED retrofit lamp market. Wurth Elec-

tronics Midcom, a global leader in the design and

manufacture of custom magnetic components, creat-

ed the Dual Coil series of common mode chokes with

high dual impedance capabilities - in the smallest

package size on the market today.

The Dual Coil series of common mode chokes offer a

cost-effective solution for suppression of common

mode and differential mode impedance at low fre-

quencies, ranging from 10kHz to 100MHz. The dual

feature eliminates the need for multiple components,

which saves cost on the bill of materials and space

on the printed circuit board.

The Dual Coil has common mode inductance values

ranging from 2.5mH to 140mH, while providing differ-

ential mode inductance from 0.3mH to 19mH. The

Dual Coil measures 8.7 mm x 15.8 mm x 13-13.6

mm. With ratings up to 250 VAC line voltages and up

to 750mA of current, these chokes can handle even

the most demanding needs in the LED retrofit lamp

market. In addition, they are well suited to fit higher

power lighting ballast applications, as well as any

low-power, offline application.

www.we-online.com/midcom

Dual Coil Combines High Common and

Differential Mode Impedance for LED Lamps

up to 400 x 1200 mm possible

due to innovative internal construction extremely low Rth

values are possible

Any dimensions possible

Superior thermal performance

Design and production

in house

up to 400 x 1200 mm possible

Any

e

due to innovative internalt ti t l l R

S

VACUUM BRAZED COLDPLATES FROM DAU

absolutely pure and homogenous leak free joints

no flux agent for brazing necessary

NEW TECHNOLOGY

- AUSTRIA DAU Ges.m.b.H. & Co. KG

Tel: +43 (0) 3143 / 23 51- 0 [email protected]

- USA DAU Thermal Solutions Inc.Phone: +1 519 954 0255

[email protected]



International Rectifier has introduced a family of DirectFET®plus

power MOSFETs featuring IR’s new generation of silicon that sets a

new standard in efficiency for 12 V input synchronous buck applica-

tions including next-generation servers, desktops, and notebooks.

The first two DirectFET®plus devices in the new family, the IRF6811

and IRF6894, reduce on-state resistance (RDS(on)) and gate charge

(Qg) compared to previous generation devices to significantly

improve efficiency up to 2 percent. In addition, the devices offer ultra

low gate resistance (Rg) enabling further efficiency improvement by

minimizing switching losses in DC-DC converters.

The IRF6811 and IRF6894 chipset leverages IR’s DirectFET® pack-

aging technology and features a new generation of silicon which opti-

mizes key MOSFET parameters to provide a best-in-class solution

that delivers excellent performance, high reliability, and small footprint

for next-generation computing needs.

The IRF6811 control MOSFET is available in a Small Can while the

IRF6894 synchronous MOSFET is offered in a Medium Can. The

25 V DirectFET®plus pair combines industry leading RDS(on) and

Rg, combined with low charge to minimize conduction and switching

losses. The IRF6894 also features a monolithically integrated Schot-

tky that reduces losses associated with body diode conduction and

reverse recovery. The new DirectFET®plus MOSFETs are footprint

compatible with previous generation devices.

www.irf.com

IR’s New DirectFET®plus for DC-DC Switching Applications

Wurth Electronics Midcom Inc. and Infineon

Technologies have teamed up to create the

ICL8001G LED driver application for

40/60/100W incandescent bulb replacement

for US and European markets. The design

provides unmatched power quality, with a

power factor exceeding 95%.

Featured on the ICL8001G design is a cus-

tom Wurth Electronics Midcom flyback trans-

former (US: 750311798; EUR: 750815141)

and WE-TFC series (744862120) power line

common mode choke. The transformer pro-

vides high energy storage in a compact

design with low copper losses. The design

offers reinforced insulation to IEC61558-2-17

and has an operating temperature from -

40°C to +125°C. The common mode chokes

feature high suppression of symmetric inter-

ferences, even at low frequency ranges.

Regardless of the small size, the choke pro-

vides low copper losses. Operating tempera-

ture range is -55°C to +105°C.

The LED lighting design is a quasi-resonant

controller that creates an ideal solution for

dimmable retrofit LED light bulbs. The

ICL8001G offers efficiencies up to 90% with

superb light quality. The solution uses pri-

mary side control which results in a fully iso-

lated design without requiring additional

components. With the reduced component

count, this design results in approximately

30% BOM savings. Multiple safety functions

also ensure a full system protection in failure

situations.

www.we-online.com/midcom

Technologies Partner on LED Lighting Reference Design

Today the car industry is still working on

even better ways for loading an electric

vehicles (EV) battery. It ought to be conven-

ient, quick, clean and safe – „refueling“ the

car battery - instead of tangled , dusty wires

in the trunk, vandalism at the electricity fill-

ing stations or unsuccessful loading

processes because the plug did not properly

fit.

LIC© stands for Lasslop Inductive Charging.

Using compressed winding technique the J.

Lasslop GmbH in Hünfeld (Germany) has

developed a wireless, highly efficient induc-

tive transmission system with an overall-

electric efficiency of >94%.

These systems performance range from a

few watts up to 500 kW. The maintenance

free LIC©-transformer-systems are excep-

tionally small and light.

Thus the SMTU-unit of the LIC22-trans-

former with a dimension of 300x200 mm and

a performance of 22 kW has just a weight of

1500 g. Its aerial gap is 80mm, other/bigger

air gaps are possible.

Developing the LIC© systems the J. Lasslop

GmbH is able to offer a non-contact trans-

mission of energy and data bidirectionally -

which means transfer in both directions.

"Power-to-the-grid" implies returning the

energy back to the electricity net. This idea

is not only highly attractive for the big elec-

tricity enterprises, but yet for every end con-

sumer.

www.j-lasslop.de

High Efficient Inductive Transmission is Called LIC©

ANNOUNCEMENT

Power Electronics and Adjustable Speed Drives: Towards the 20-20-20 Target!

Announcement www.epe2011.com



Tyco Electronics unveils three new embed-

ded magnetic product offerings from its

recently acquired PlanarMag product tech-

nology – a revolutionary embedded magnet-

ic innovation that fully automates traditional

hand-wound coiling processes. This new

advancement enables economic and manu-

facturing scalability to provide faster manu-

facturing cycle times during periods of high

demand and allows for consistent product

lead time and supply.

“Our technology will significantly speed prod-

uct time-to-market and increase supply chain

capacity while improving the overall reliability

and quality of our product. It helps minimize

cost impacts, which arise from labor pool

instability and increasing labor costs,” says

Sabi Varma, Director of Magnetics, TE. “This

technology is truly an innovation for Ethernet

products.”

The PlanarMag product technology capital-

izes on three innovations to dramatically

improve the design and manufacture of elec-

tromagnetic components:

Use of proprietary material to embed highly

sensitive magnetic ferrites into standard

PCBs

Utilization of a 3D-electromagnetic simulator

with unique design techniques to create

patented proprietary winding structures

Standard PCB processes to manufacture

boards containing hundreds to thousands of

parts at once, with dramatically improved

performance and consistency, while utilizing

semiconductor testing methodologies

www.te.com/products/planarmag

Embedded Magnetic Products

ROHM Semiconductor

has announced the

development of the

BP5275 series of step-

down DC/DC converter

modules that integrate

all required external

components, including

input/output capacitors,

into a compact, high

heat dissipation pack-

age. This makes them

ideal for use as gener-

al-purpose power sup-

plies in a variety of

electronic devices.

Currently, multiple LDOs, switching regula-

tors, and numerous other electrical compo-

nents are essential in order to provide stable

electrical power to internal circuits. However,

the relatively large amount of heat generated

by each component requires separate heat

sinks or additional substrates to facilitate

heat dissipation, making miniaturization diffi-

cult. Also, multiple tedious circuit design

processes, including selection of external

components based on phase compensation,

FET voltage, and heat dissipation character-

istics, are necessary, increasing develop-

ment time and costs.

In response to this, the BP5275 series was

developed, utilizing an in-house high-fre-

quency (1.5MHz) switching regulator IC and

synchronous rectification system for high

efficiency operation (93% for 6V?5V conver-

sion). As a result, mounting area is reduced

to 1/6th of the conventional size. The new

high-heat-dissipation package enables direct

heat dissipation from the device(s) to an alu-

minum heat sink. An external heat sink can

be mounted, increasing output current capa-

bility to 800mA. In addition, the 3-terminal,

pin-compatible configuration enables major

increases in power supply efficiency without

requiring comprehensive modifications,

reducing development time and costs.

www.rohm.com/eu

High Efficiency Step-Down DC/DC Converter Modules


Featuring up to 97.4 percent power efficien-

cy and a highly efficient design using nearly

30 percent less material, the VPT Series

Toroidal Power Transformers from Triad

Magnetics provide an innovative green

power electronics solution that is also small-

er and lighter than traditional transformers.

Compared to conventional EI transformers,

toroidal construction inherently helps reduce

stray fields, increases efficiency and mini-

mizes size. Triad's new transformers are

constructed with a Class B, UL approved

insulation system rated for 130°C that pro-

vides 4000V primary to secondary isolation.

The highly efficient VPT Series is suit-

able for a wide range of applications in

commercial and industrial equipment.

The transformers operate over a broad

power range from 25 VA to 2.5 KVA,

depending on the specific model select-

ed. With dual primary and secondary

windings, it allows for maximum flexibility

of input and output voltages. The VPT

Series features an input voltage of

115/230 VAC, 50/60 Hz, and output volt-

age from 6.0V through 230V. Voltage

regulation is up to 2.5 percent from full

load to no load.

VPT Series transformers are designed

and manufactured under Triad’s

ISO9001 quality assurance program.

Thorough testing procedures assure that

Triad products meet the most stringent

global safety and environmental stan-

dards including UL, CE, RoHS and

REACH. Agency files are available upon

request.

The VPT Series features a rugged,

RoHS compliant toroidal construction in

a package ranging in size from 71 to 208

mm diameter, a height range of 32 to

112 mm and weight range of 0.4 to 19.4

kg, depending on the specific model

selected. The highest quality materials

ensure superior performance and a long

life.

www.triadmagnetics.com

Toroidal Power Transformers Offer

Efficient Electronics Design

For FREE application notes and more, please visit: www.omicron-lab.com &www.picotest.com/blog

�� Non-Invasive & traditional Stability

�� PSRR

�� Input & Output Impedance

�� Reverse Transfer

�� ... and many other important power supply parameters in the range from 1 Hz - 40 MHz

Get to know your Power Supply!

Combining OMICRON Lab’s Bode 100, Vector Network Analyzer with the new Picotest Signal Injectorsenables you to perform high-fidelity measurements of:

Smart Measurement Solutions

CUI Inc announced the addition of a 6 W

model to their low cost open frame ac-dc

power supply line. With the latest offering,

the VOF series now covers a broad range of

power from 6 W through 80 W. The com-

pact size and competitive pricing makes this

series ideally suited for consumer, industrial,

and ITE applications. All units are highly

efficient and offer leakage currents below

0.3 mA.

The VOF-6 provides continuous output

power, universal input (85-264 Vac), and is

offered in 3.3, 5, 12, 15, and 24 V dc output

voltages. The ultra-compact VOF-6 meas-

ures 2.2” x 1.4” x 0.65”. Protections for over

voltage and over current conditions are

included.

“The VOF-6 series is our smallest open

frame power supply and expands CUI’s

offerings of small, compact solutions to sup-

port customers with size constraints,” stated

Kraig Kawada, CUI’s Director of Core Prod-

uct Management. The VOF-6 is available

through Digi-Key at $10.66 for 100 pcs.

Please contact CUI for OEM pricing.

www.cui.com

6 W AC-DC Open Frame Power Supply



Summit Microelectronics has announced a new programmable DC-

DC power manager solution that brings unsurpassed functional and

feature integration with easy-to-use flexibility to wide range of appli-

cations. Summit’s SMB109 simplifies increasingly complex power

design challenges by integrating multiple DC-DC outputs with digital

power management/monitoring and non-volatile system configuration,

reducing component count, cost, size and time-to-market. The

SMB109 is ideal for powering advanced multi-rail digital chipsets in a

wide range of communications, computing and consumer applica-

tions such as notebook/netbook/tablet, server/storage, telecom/data-

com and multimedia devices. Additionally the SMB109’s high power-

conversion efficiency, output voltage control and advanced power-

down modes facilitate “Green” and EnergyStar® compliant design.

With a serial digital interface and on-board non-volatile memory, the

SMB109 can be easily configured during development and re-pro-

grammed in-system by host software. The result is a flexible, digitally

controlled power supply design that is easily customizable without

tedious hardware design cycles or complex microcontroller-style

GPIO-based control. The integration of advanced power control func-

tions eliminates external components and cost, improves functionality

and performance, and minimizes development time.

www.summitmicro.com

Programmable Multi-Output DC-DC Power Manager

Infineon Technologies offers new Easy 1B

single-phase rectifier modules with MOSFET

chopper for Power Factor Correction in order

to support customers in offering optimised

solutions. Applications for these new mod-

ules include drives, air conditioning, pumps,

fans and welding.

The new modules come with several advan-

tages: CoolMOS™ Power Transistors plus

ThinQ!™ Silicon Carbide Schottky diodes

enable highest efficiency of the PFC stage.

Infineon 50A rectifier diodes provide very low

conduction losses. Higher output currents

can be achieved using the same line input.

Up to 5.5 kW inverter rating are achievable

from only 16A single phase input current.

Highest reliability can be achieved due to

PressFIT contacts.

Electromagnetic Compatibility (EMC) is an

important topic in power electronics. Accord-

ing to IEC 61000-3-2 electrical and electron-

ic equipment having an input current up to

and including 16 A per phase, and intended

to be connected to public low-voltage distri-

bution systems as well as arc welding equip-

ment which is not professional equipment,

with input current up to and including 16 A

per phase, is subject to limits for harmonic

current emissions.

www.infineon.com

Rectifier Module with integrated MOSFET Chopper for PFC

Renesas Electronics announced the devel-

opment of an optical-coupled metal-oxide-

semiconductor field-effect transistor (MOS-

FET), the PS7901D-1A, that achieves com-

plete electrical isolation within the package

by using light for signal transmission.

The PS7901D-1A device features an indus-

try-leading ultra-compact 4-pin flat-lead

package measuring only 2.9 millimeters

(mm) × 2.3 mm, which is 40 percent smaller

than that of Renesas Electronics' existing

PS78 Series products, while retaining a

guaranteed isolation voltage of 500 volts (V)

r.m.s., equivalent to the company's existing

products. The MOSFET chip inside the pack-

age combines low output capacitance and

low leakage current. The extremely low leak-

age current when in the off state makes the

PS7901D-1A suitable for high-frequency sig-

nal control in applications such as IC testers.

An optical-coupled MOSFET device com-

bines in a single package three different ele-

ments: on the input side a light-emitting

diode (LED) that converts an electrical signal

into light, on the output side a photo voltaic

diode (PVD) that converts light into an elec-

trical signal, and an output MOSFET. The

use of light to transmit the signal means that

the input and output sides are completely

isolated from each other electrically. This

type of device is also referred to as a solid

state relay (SSR). In contrast to mechanical

relays, semiconductor relays are not subject

to malfunction due to worn contacts or con-

tamination by foreign matter. For this reason,

mechanical relays are being replaced by

solid state relay (SSR) in a wide range of

applications, including IC testers, factory

automation equipments, electric household

appliances, and communication equipments.

www.renesas.eu

Optical-Coupled MOSFET with Low Output-Capacitance

www.pcim.com



ABB France 21

ABB Semi C3

APEC 50

Berquist 3

CDE 31

Cirrus APEX 25

CPS 33

CT Concept Technologie 17

CUI 51

Curamik 1

CWIEME 58

Danfoss Silicon Power 49

Dau 55

EBV 15

embedded 42

EPE 57

Fuji 19

GVA C2

H2expo 45

Husum New Energy 43

Infineon 7

International Rectifier C4

Intersil 5

ITPR 47

Indium 13 / 41

ixys 37

J&D 47

Lem 53

Micrel 39

Mitsubishi 11

Omicron 59

Payton 21

PCIM 61-63

Proton 35

Semikron 9

Sonoscan 23

Toshiba 51

VMI 33

Würth Electronic 45

ADVERTISING INDEX

High energy medical imaging systems such as MRI and CAT scan-

ners benefit from new, ultra reliable IGBT control system power

sources.

Bicron® Electronics provides high voltage IGBT Gate Drive solutions

that protect against damaging partial discharge (corona).

Bicron’s Gate Guard series high frequency gate drive transformers

are unique in that they are custom engineered for maximum compati-

bility with a customer’s specific IGBT power control circuit. They are

designed to achieve optimum electrical balance with minimum need

for power draining compensation components.

Designed for operation with IGBT power control systems operating

up to 1200V, these transformers provide reliable isolation against

voltage spikes, surges and similar phenomena up to 20KV.

For over 30 years, Bicron designed magnetics have proven their reli-

ability in demanding installations involving wind energy, solar power,

rail locomotion, and high horsepower industrial motor control.

More information is available at: http://www.bicron-magnetics.us.

www.bicron-magnetics.com

Ultra Reliable Control Power Source for

High Energy Medical MRI and CAT Scanners

TDK-Lambda adds a 200W model to its successful single output LS

series of general purpose power supplies, with models now covering

from 25W up to 200W. While the LS200 is particularly well-suited to

budget conscious applications, it carries more functions than similarly

priced products available on the market today and can fit into a 1U

rack.

The LS200 has a universal input range of 85 to 264Vac (47-63Hz)

with PFC meeting EN61000-3-2, 3, and can withstand a 300Vac

surge for five seconds. Over current with constant current limiting,

over voltage and over temperature protection circuitry are standard

features of the LS200, as well as remote on/off signal, green LED

‘ON’ indicator and remote sensing. Available either enclosed with low

noise fan or U-channel style with convection or customer airflow cool-

ing, the efficient design of the LS200 achieves excellent thermal bal-

ance and 299K hours MTBF – up to 63% longer than competitor

examples.

Nominal output voltages range from 3.3 to 48Vdc, delivering currents

of up to 40A. To accommodate non-standard system voltages, the

LS200 is user adjustable by up to -10/+20% (for 12V, 24V & 48V).

Offered with an extended -25 to +70°C operating temperature range,

the LS200 thermal design enables full power output up to 50°C and

60% output power at 70°C. Furthermore, the 24V and 36V output

voltage models have 250W peak power capability.

As well as meeting EN55011/EN55022 class B conducted and radiat-

ed emissions, LS200 meets UL/IEC 60950-1 edition 2 safety

approvals and carries the CE mark. The LS200 series comes with a

three-year warranty. Size is 199 x 98 x 41mm.

www.emea.tdk-lambda.com

Single-Output, Power Supplies Increase to 200W

Power and productivityfor a better world“

High Power IGCT. Whatever performance

you need.

ABB Switzerland LtdSemiconductorsTel: +41 58 586 14 19

www.abb.com/semiconductors

IGCTs manufactured by ABB Semiconductors are thoroughly tested on their static

and dynamic performance. For some devices up to 20MW simultaneous power is

switched. This to ensure reliable operation in applications like medium voltage drives

and trackside power supply. For more information please visit our webpage:

www.abb.com/semiconductors

Power D

ensity

Your FIRST CHOICE

for Performance

DirectFET®

PQFN

D-Pak

SO-8

Part NumberBV

DSS

(V)Function Package

RDS(on)

Max.

VGS

=10V

(m�)

QG

VGS

=4.5V

(nC)

IRFH5306 30 Control High Current PQFN 5 x 6 8.1 7.8

IRFH5302 30 Sync High Current PQFN 5 x 6 2.1 29

IRFHM831 30 Control PQFN 3x3 7.8 7.3

IRFHM830 30 Sync PQFN 3x3 3.8 15

IRFHM830D 30 Sync PQFN 3x3 4.3 13

IRFH7911 30Control Half-Bridge Asymmetric

PQFN 5x6

8.6 8.3

Sync 3.0 34

IRLR8729 30 Control D-Pak 8.9 10

IRLR8726 30 Sync D-Pak 5.8 15

IRF8714 30 Control SO-8 8.7 8.1

IRF8734 30 Sync SO-8 3.5 20

IRF8513 30Control Half-Bridge Asymmetric

SO-815.5 5.7

Sync 12.7 7.6

The IR Advantage

Scalable Solutions for DC-DC Buck Converters

Select The Best MOSFET Pair to

Meet Your Power Density Needs

THE POWER MANAGEMENT LEADER For more information call +49 (0) 6102 884 311

or visit us at www.irf.com

Bandwidth PSRR of LDOs

Documents

Transcript of Bandwidth PSRR of LDOs