ERICSSON POWER MODULES
3E – Enhanced performance, Energy management and increased End-user value with digital POL regulators
Ericsson Power Modules’ new digital POL (point-of-load) regulators establish an innovative approach to
reach the goals of end-user value, flexibility and system performance. These new power supply products
contain several unique concepts and features spanning the disciplines of mechanical packaging, electrical
design, control loop algorithms, power system architecture, power and energy management tools and lo-
gistics during system manufacturing and field support. These POL regulators are the first in a broader line of
Ericsson Power Modules’ digital power products, including isolated DC/DC converters, that will embody these
concepts and features. Because of the wide-ranging impact of these new designs and the resulting benefits
to the customer, it is important that prospective users understand the fundamental principles behind these
products. The user will discover that while the internal design of these POL regulators is quite advanced
relative to the now prevailing analog technology their flexibility is greatly increased and their application to
end-user products can actually be simplified relative to conventional POL regulators. This brochure will
focus on these benefits for the power system designer.
Ericsson Power Modules refers to the high-level end-user benefit of this design approach as “3E”,
the 3 Es being:
• Enhanced Performance
• Energy Management
• End-user Value
We will explore all three of these areas and these new POL regulators will be referred to generically as
“3E POL regulators”.
The next section will describe some of the concepts, terminology and definitions used when working with
the 3E POL regulator designs and power system architectures enabled by the new products. This is fol-
lowed by a description of the 3E POL regulator offerings and then a more detailed treatment of the benefits
to the end-user in the areas of mechanical features, electrical performance, system power and energy
management, and overall value. The last section expands the discussion of the 3E concept and explores its
ramifications for the end-user.
1. Introduction
The internal design of the 3E POL regulators uses digital
power control techniques, and some of the optional
user implementations of these products can benefit
from utilization of system level digital power and energy
management approaches. While these products can be
successfully applied using the same techniques as with
conventional fully analog POL regulators, it is beneficial
for the customer to become somewhat conversant with
the digital approaches to be able to make the optimal
choice for their particular system between conventional
and digital techniques. This section will describe the dis-
tinctions between digital power control and digital power
and energy management. It will also compare them to
conventional completely analog designs. The treatment
here will be very generalized, but references will be cited
so that the reader may explore these areas in more detail
if desired.
This brochure primarily supports the introduction of the
3E POL regulators and does for that reason focus mostly
on this element of the system. The following discussion,
however, will often apply conceptually to other system
elements such as isolated DC/DC converters, front-end
power conditioning hardware and thermal management
devices. During this discussion it will be assumed that a
fairly conventional Intermediate Bus Architecture (IBA) is
used such as that shown in Figure 1. A board-level Inter-
mediate Bus Converter (IBC) feeds multiple POL regula-
tors which are located in proximity to the load circuitry
and supply the final operating voltages. The IBC output
voltage, will typically be between 3.3 and 12 Vdc.
A conventional analog POL regulator uses an analog
PWM (pulse width modulation) control IC to generate the
gate drive waveforms for the power MOSFET switches.
The voltage feedback loop is implemented with analog
comparators, and the stability/compensation circuitry is
composed of linear R, L and C networks. Internal fault
monitoring and detection is done with analog sensors and
comparators. The user configurability of these POL regula-
tors is often rather limited, with resistive trim or output
voltage programming being the most commonly used
modification. These designs have been in use for many
years.
Ericsson Power Modules uses the term “digital power
control” to describe a DC/DC converter or POL regulator
design in which much of the analog control functional-
ity is replaced with digital circuitry. Typically the digital
content will include the feedback loops, MOSFET gate
drive generation, stability control, and fault detection.
The power train with MOSFET switches and the main
output LC filter is similar to what is used in an analog
POL regulator. The main point to be made here is that
digital power control can be transparent to the end-
user. Two power devices, one implemented digitally
and one with analog circuitry, can be plug-compatible
and may even be indistinguishable as far as the user is
concerned. However, as we will see later, using digital
techniques internal to a POL regulator can offer signifi-
cant size and performance advantages to the end-user
as well as drastically increasing the regulator’s flexibility
2. Concepts, Terminology & Definitions
and configurability. The reader is directed to reference
(1) for additional detail on the concepts of digital power
control as it applies to POL regulators.
While digital power control only applies to circuitry con-
tained within a power supply and is designed and con-
trolled by the power supply manufacturer, digital power
management and energy management extends beyond
the physical boundaries of a DC/DC converter or POL
regulator and into the end-use system. This extension
significantly increases the capabilities of the end-use
system, but will also require the power system designer
to participate in the implementation of the system man-
agement structure. The term “digital power manage-
ment” is used by Ericsson Power Modules to describe a
concept where digital communication between DC/DC
converters and/or POL regulators or other elements in
the system, for the purposes of monitoring and con-
trolling the status of the power supplies, minimizes the
system power and energy consumption and optimizes
the overall performance of the system. This digital com-
munication is typically used for the functions of power
monitoring, power on/off, output voltage setting, fault
handling, and power sequencing and is facilitated by a
digital interface, referred to as the power management
bus (PMBus™).
The analog-based hard-wired circuitry and multi-con-
ductor wiring used for these functions in a conventional
system are replaced with a digital communication bus
structure that simplifies the interconnections and allows
for programmable rather than fixed functionality. Refer-
ence (2) explains how a digital interface for this purpose
can be added to a POL regulator without impacting
the cost. While digital power control must operate on a
cycle-by-cycle basis to control the energy flow, digital
power management usually operates on a slower time
scale to react to changes within the system.
The efficiency of DC/DC converters and POL regula-
tors has always been a key performance criterion, and
is receiving even more attention in recent years as more
emphasis is placed on power and energy consump-
tion and the environmental impacts of large scale data
processing and telecom installations. Digital power adds
another dimension and the synergy between digital
power control and digital power management results in
further system efficiency improvements and lower energy
consumption. Digital power control allows for “on-the-fly”
reconfiguration of operating parameters within a power
supply. In a conventional DC/DC converter or POL regu-
lator many operating parameters are fixed, resulting in an
efficiency that is a compromise based on the expected
range of operating conditions in the system. If a digitally
controlled POL regulator or DC/DC converter is oper-
ated in a system with digital power management, the
system status can be used to dynamically program the
operating conditions of the power supply. For example,
the PWM dead-time can be varied as a function of the
regulator’s input and the load voltage and output current
to optimize the real time efficiency over a broad variety of
operating conditions.
Similarly, the output voltage of an IBC can be dynamically
varied to optimize the overall efficiency of the combina-
tion of IBC and POL regulator as a function of the current
system operating condition. Effects of power conversion
component variations due to ageing may also be com-
pensated for in this way. Ericsson Power Modules refers
to this combined usage of digital power management
and digital power control for the purpose of optimizing
the overall power efficiency of the end-use equipment
as a function of actual operating conditions as “digital
energy management”. Impressive savings in energy
consumption can be achieved in this way. In effect, digital
energy management replaces compromise with optimiza-
tion. Reference (3) describes these possibilities in greater
depth. References (4) and (5) discuss similar concepts as
applied to DC/DC converters.
48V/24V DC
3.3 V
1.8 V
1.5 V
12V/9V/5V/3.3V
Figure 1 In an Intermediate Bus Architecture (IBA) a board-level Intermediate Bus Converter (IBC) feeds multiple POL regulators which are located in proximity to the load circuitry and provides a well regulated supply voltage.
2. Concepts, Terminology & Definitions
This section will discuss the benefits of the new
3E POL regulators in some detail. It starts with an over-
view of the planned initial product offerings, which will
cover the output current range of 20 A and 40 A. Later
introductions will expand this current range. These 3E
POL regulators are extremely flexible, with the capability
of efficiently spanning an input voltage range of 4.5 to
14 V and an output voltage range of 0.6 to 5.5 V. Each
3E POL regulator includes a connector that is used for
the purpose of interfacing to the PMBus, see 3.3.2.
Each POL will be available in either SMT or PTH (plated-
through-hole) packages with a common interconnection
footprint to allow easy system scalability. A photograph
of the initial 3E POL regulators is shown in Figure 2.
3.1 MECHANICAL FEATURES
Ericsson Power Modules has shipped more than
50 million BMPS (board mounted power supplies)
over the years, and has developed an industry leading
expertise in designing packages that are cost effective
in manufacturing and extremely reliable in the field. A
new packaging and interconnect concept was required
for the 3E POL regulators since a power management
interface needed to be included. We looked upon this
new requirement as an opportunity to optimize the entire
POL regulator physical package and incorporate several
features that provide substantial benefit to the end-user.
The incorporation of digital control techniques and the
new package design provides increases in footprint areal
current density (A/cm²) of up to 300% and a correspond-
ingly significant increase of the power density. The low
building height also allow these devices to be used in
systems with a board pitch down to 15 mm. The physical
dimensions of the new 3E POL regulator products are:
Current Rating Overall L x W x H (mm)
20 A 25.7 x 12.9 x 8.2
40 A 30.9 x 20.0 x 8.2
3. Benefits of new POL offerings
40 A
20 A
10 A
Figure 2 40 A and 20 A 3E POL regulators.
Figure 3 The footprint layouts of the 10 A, 20 A and 40 A 3E POL regulators are scalable. A single PCB layout can accommodate any of these products.
Most conventional BMPS use connection pins with the
same design regardless of the pin function. Pins carrying
20 A could be the same physical size as pins carrying
a couple of mA. This is obviously not cost-effective and
is a waste of valuable PWB real estate. For the 3E POL
regulator products Ericsson Power Modules took a fresh
look at the interconnection issues and created a new
optimized header design. For power input and output
pins carrying large amount of current thick low resistance
pins are used. For other interfaces such as remote sens-
ing, clock and data lines that conduct minimal current
an industry standard connector header is selected. This
selection, in addition to reducing the footprint dimen-
sions, results in cost savings to the end user. The low
current connector header is widely used in the industry
with high production volumes and low cost. This selec-
tion also eliminates the technical risk of developing a new
pin design.
A major design decision was to make the footprint
layouts of the different 3E POL regulators scalable.
The power system designer can create a single board
layout that will accommodate any of these products.
This is especially valuable in terms of minimizing costly
and time-consuming layout changes during the product
development cycle when the exact current requirements
are not well defined. This concept is depicted in Figure
3. Note that the digital power management interface pins
on the right side of the drawing remain the same for any
of the three regulator families. The larger input and output
power pins to the left can be bussed together on the
user’s PWB to provide connection to any 3E POL regula-
tor with an output current rating from 20 A to 40 A.
The selected pin layout has an added advantage during
the customer’s manufacturing process. Notice in Figure 3
that the pins are bunched into three groups – the power
management connector on the right and the upper and
lower group of high current pins on the left. This grouping
forms a “three legged stool” structure which minimizes
coplanarity problems during SMT reflow soldering pro-
cesses. Sizeable components, such as POL regulators,
with pins in each of four corners can potentially present
difficulties in this regard. The reader need only compare
experiences in the amount of wobble in three legged
stools vs. four legged tables to be convinced of this
benefit!
All POL regulators in the 3E families feature an output
inductor with a flat surface oriented to the top of the
package. This is intentionally designed as a convenient
attachment point for vacuum nozzle pick and place
equipment. Both tray and tape & reel device packaging
will be available to maximize compatibility to the user’s
manufacturing process. Both SMT and PTH options will
also be offered. Figure 4 is a photograph showing more
detail of the interconnection offerings.
3.2 ELECTRICAL PERFORMANCE
This section summarizes the fundamental electrical
performance characteristics of the 3E POL regulators. As
will be seen in the next section, these fundamental per-
formance parameters can in some cases be enhanced
when using digital power management and digital energy
management at the system level.
The broad input voltage range (4.5 V to 14 V) of the 3E
POL offerings allow them to operate with the most com-
monly used intermediate bus voltages of 5 V, 9 V and
12 V. The output voltage range extends from 0.6 V up to
5.5 V.
The efficiency of these products is in line with the best
solutions currently available and it can be improved even
further by use of digital control and power management
Figure 4 The 3E POL regulators are designed for either surface mount or plated through-hole mount manufacturing processes, giving the user a flexibility of choice.
techniques. Efficiency data both in a “stand-alone” mode
and when operating with digital power management
feedback from the system will be given in the next sec-
tion. Similarly, the excellent dynamic response character-
istics of the 3E POL regulators can be further optimized
by means of system-level feedback, and comparative
data will be shown.
Perhaps the biggest improvement in electrical perfor-
mance visible to the casual observer is in the realm of
physical size and power density. This is primarily due to
the significantly lower parts count inherent in a POL regu-
lator designed with digital power control techniques. The
table below summarizes the power and current densities
of the 3E POL products compared with a traditional
18 A analog POL regulator. These data assume an output
voltage setting of 3.3 V at max rated current and an input
voltage of 12 V. Keep in mind that these improvements
were made in spite of including the new interface for
digital power management.
DEvICE POWER DENSITy AREAL CURRENT
W/cm³ DENSITy A/cm²
18 A Analog POL 7.4 2.1
20 A 3E POL 24.3 6.0
40 A 3E POL 26.1 6.5
A photograph showing the relative size difference of
the above products is shown in Figure 5. While steady
power and current density improvements have been
common in the POL regulator market, the step function
packaging density gains shown by the 3E digital POL
regulator designs are unprecedented.
While the digital power management connector was added
primarily for that purpose, it also contains some pins that
may be used to obtain more conventional analog func-
tions. Remote sense connections are provided for both the
positive and negative POL output terminals. These can be
used to regulate the POL output voltage accurately at the
load. The digital power management connector may also
be used for other features like current share and synchro-
nization. A direct current share connection can be made
between 3E POLs through another pin on this connector.
With this connection the POLs will automatically current
share without further need for external control. For ex-
ample, two 40 A POL regulators can power a load with a
requirement of up to 80 A. Another pin may be used for al-
lowing two or more 3E POL regulators to synchronize their
Synchronization
Remotesense
Currentshare
out0.6 – 5.5 V
3.3 / 5 /9 / 12 V in
out0.6 – 5.5 V
Figure 6 The digital power management connector may be used for many well-known features such as remote sense, current share and synchronization.
Figure 5 From left to right relative size difference of a traditional 18 A ana-log POL regulator compared to the 20 A and 40 A 3E POL regulators.
POL-to-POL bus 3.3 V
1.8 V
1.5 V
switching activity with each other or with an external oscilla-
tor. This feature could be used to facilitate filter design and
reduce the input ripple current. Figure 6 depicts a system
in which three POLs are synchronized and interleaved and
two of them are configured in a current sharing arrange-
ment.
3.3 SySTEM POWER AND ENERGy MANAGEMENT
3.3.1 Power Management Methodologies
The 3E POL regulator offerings are extremely flexible in
terms of available management methodologies that can
be applied during the life cycle of the end-use applica-
tion. In order of increasing functionality they can be sum-
marized as follows:
1. The 3E POL regulator can be treated the same as a
conventional POL with internal analog circuitry. Con-
necting the POL to the input voltage bus and selecting
the output voltage by means of an external trimming re-
sistor is all that is required to operate the 3E device as a
conventional POL regulator. The digital power manage-
ment interface can be ignored. This would enable the
3E POL regulators to be utilized in systems that have
no need for a more sophisticated control system or that
have an existing analog-based control implementation.
Note that with this scenario many of the performance
benefits of the 3E products such as increased efficiency
and power density could still be realized.
2. A dedicated POL to POL bus can be used without
having the PMBus connected to a host controller dur-
ing system operation. The POL to POL bus is a single
wire connection via a dedicated pin. An example of
this is found in the previous section when current
sharing and POL switching synchronization capabili-
ties were discussed. This control methodology will
provide some degree of power management based
on a pre-configured set of 3E POL regulators. For
example, the start-up and shut-down sequencing can
be defined, current sharing established, or a selected
group of regulators could be tied together so that they
all would shut down in response to a fault condition
on any one of them.
3. The PMBus can be used for digital communication
between the 3E POL regulators and a host controller.
This host controller can be a part of each board-level
power system or can be only a temporary connection
to an external host during the product development
and/or manufacturing process. This is by far the most
flexible option in terms of obtaining maximum benefit
and optimization by means of digital power manage-
ment.
A drawing showing these three levels of control implemen-
tation is shown in Figure 7.
Figure 7c The PMBus can be used for digital communication between the 3E POL regulators and a host controller.
Figure 7a The 3E POL regulator can be treated the same as a conven-tional POL using an external trimming resistor for adjusting the output voltage.
Figure 7b A dedicated POL to POL bus can be used for power management without having the PMBus connected to a host controller during system operation.
7 a 7 b
7 c
3.3 V
1.8 V
1.5 V
Analogresistor trim
3.3.2 The PMBus
The PMBus is a bidirectional serial multi-node interface
that utilizes 4 conductors with the following functions:
• Clock (SCL)
• Data (SDA)
• Control (CTRL)
• Alert (SALERT)
The clock and data lines are used for the bidirectional
transfer of data between the host and the controlled
nodes (3E POL regulators in this case) in the network.
The Control line is hardwired to a regulator pin for the
purpose of enabling the output. The Alert line is used, as
an alarm, by the connected POL regulators to gain the
attention of the host controller.
Individual 3E POL regulators are identified to the host
controller by means of an assigned address. These ad-
dresses are physically assigned at each POL regulator
used in the system by means of resistive programming.
One or two pins in the power management connector are
available on each 3E POL for this purpose, and chip re-
sistors are connected from these pins to Gnd to establish
the programming. Twentyfive pre-defined discrete values
of resistance are used per pin, providing a total of up to
625 combinations, which is more than enough since the
PMBus specification is limited to 128 unique addresses.
Note that in a typical system some of these addresses
would be used by other power system components such
as DC/DC converters, fans and AC/DC rectifiers.
3.3.3 Usage of the PMBus
While usage of the PMBus is optional, its use will greatly
increase the flexibility of the end application’s power
system. If BMPS products with PMBus connectivity are
used in the system, it really only requires the bussing of
the 4 conductors previously identified to a host location
in order to take advantage of the benefits of digital power
management. One common misconception is that the
host controller must be resident in the end system. While
this is one option, it is not the only one. The following
three scenarios show how the PMBus could be used
during various phases of the end-use system develop-
ment, manufacture and deployment.
1. The PMBus is used during product development and
evaluation. The host controller in this case could be
an external PC connected to the prototype system or
sub-system. This is an extremely convenient and fast
way to experiment with such things as voltage set-
tings, overcurrent limits, power sequencing routines,
voltage margining, fault handling, etc. without the
need for hardware changes in the system. Ericsson
Power Modules has an evaluation kit for the 3E POL
regulators that contains an extensive Configuration
Monitoring and Management (CMM) software and is
an excellent way to begin exploring this type of capa-
bility. No host controller is required in the system itself.
2. The PMBus is used during system manufacturing and
test, and the host controller could be part of the Auto-
mated Test Equipment (ATE). In this scenario the ATE
could automatically configure the 3E POL regulators
during the system’s manufacturing process. Param-
eters such as output voltage, start-up delay and over
temperature/current/voltage limits can be established
during this process. No host controller is required in
the system itself.
3. The scenario with the most capability and flexibility
is to include the host controller into each board-level
power system. With this configuration the same
host controller can be used for all three phases of a
system’s lifetime – development, manufacture, and
field deployment. Another misconception is that the
host controller needs to be powerful and expensive. In
reality, its specifications are very modest and in many
systems it can be as simple as a general purpose
microcontroller or some spare gates of an FPGA that
may already be resident in the system. A representa-
tion of a system power board using 3E POL regulators
and connection to a system-level host via the PMBus
is shown in Figure 8.
3.3.4 Examples of optimization using
Power/Energy Management
This section assumes that the power system designer
has decided to use the PMBus in one of the implemen-
tations described above, and will give some examples
of how the power system may be optimized by digital
power management techniques. These are only a very
few of the many possibilities. The reader is encouraged to
think about other ways to use these capabilities in his/her
own systems.
Today’s circuitry often operates at very low static voltage
levels, below one volt in some cases, and still requires
tight power supply regulation, such as +/- 1%. Providing
these tolerances at low voltage levels is a severe chal-
lenge when considering distribution paths, component
variability, changing current demands and even tempera-
ture changes. Using a host controller in the manufactur-
ing ATE or even in the end product itself can greatly facili-
tate making these voltage level adjustments automatically
while optimizing the setting for each particular system.
The 3E POL regulator is an ideal solution for such situa-
tions. See Figure 9.
Using the PMBus in conjunction with a host controller in
the manufacturing ATE makes for fast and reliable setting
of power sequencing routines. This represents a vast
improvement in complexity relative to traditional systems
that used analog-based power controllers for this pur-
pose. It is also easy to implement voltage margin testing
during manufacturing to verify system operation over the
extremes of the design space. See Figure 10.
Accuracy and set-point improvement
V
+ 5 %
- 5 %
out
+ 1 %
- 1 %
Voltage margining
V
+ 5 %
- 5 %
out
Sequencing(V)
Figure 8 Including a host controller into each board-level power system means that the PMBus could be used during various phases of the end-use system development, manufacture and deployment.
Figure 9 The 3E POL regulator shows its worth by allowing voltage rails to be fine-tuned per board assembly to offset varia-tions in component and distribution paths, minimizing voltage rail tolerances at the actual payload circuitry.
Figure 10 The PMBus interface facilitates voltage margin testing during manufacturing as well as to configure sequencing start-up and shut-down of multiple voltage rails in a power system.
Fault detection and handling can be easily optimized.
The host controller can be programmed to set custom-
ized limits on each of the fault sensors (temperature,
voltage and current) not only for absolute limits but also
for “warning” conditions, as shown in Figure 11. In ad-
dition to these classic indicators of a major parameter
gone awry, it is also possible to predict future failures by
monitoring indicators such as operating efficiency. A pat-
tern of continuously declining efficiency allows for a Field
Replaceable Unit (FRU) to be replaced before an actual
equipment failure occurs. For systems with high availabil-
ity requirements this capability is quite valuable. The host
controller may be used to store a user selectable history
of performance parameters for the purpose of facilitating
root cause analysis in the event of a failure. This operat-
ing parameter data can also be used to collect reliability
data for the purpose of improving robustness in future
designs. A host controller is required for these types of
capabilities.
Traditional POL regulators are designed with the best pos-
sible efficiency characteristics over the expected range of
use. This range includes the input voltage selection, the
programmable output voltage range and the variation in
possible output current. Obviously, the overall efficiency
curve must be a compromise. If the POL designer was de-
signing for one particular combination of input voltage, out-
put voltage and operating current, then the efficiency could
be optimized for this particular operating condition. This is
exactly what can be accomplished by using the PMBus
in conjunction with a host controller in the manufacturing
ATE or in the system itself. The already excellent efficiency
depicted in Figure 12 can be improved even further by
configuration and optimization of the power system for it’s
intended line and load conditions. This is described more
in detail in reference (3).
A similar situation exists with the POL dynamic response
characteristics. These are dependent not only on the
circuitry inside the POL, but also on the dynamic load
profile in the application and on the amount and type of
decoupling capacitance in the end system. Knowledge of
these factors can allow a 3E POL regulator to operate in
an optimized manner as shown in Figure 13. The default
configuration allows for stable operation with a wide
range of capacitance on the output, but this inevitably
leads to compromises in performance. The optimized
configuration exemplifies how the dynamic performance
can be improved by reconfiguring the POL regulator for
its intended use with a known output capacitance. Using
this technique could allow the removal of a significant
amount of output capacitance and result in system cost
savings. These last two examples show just how power-
ful the concept of digital power management can be. You
no longer need to accept compromise – you can have
optimization!
Con�guration
Fault
Warning
Warning
Fault
Figure 11 Warning and fault thresholds for temperature, voltage and current can be individually configured on each 3E POL regulator.
Figure 12 The already excellent efficiency of a 3E POL regulator can be improved even further by configuration and optimization of the power system for its intended line and load conditions.
4.5 V in, 3.3 V out
5 V in, 3.3 V out
12 V in, 3.3 V out
%
A
14 V in, 3.3 V out
100
95
90
85
80
75
0 4 8 12 16 20
3.4 END-USER vALUE
This paper has so far concentrated on how the 3E POL
regulators can provide measurable benefits to the user in
terms of the design, manufacturing and operation phases
of the product lifecycle. These benefits have been mostly
technical in nature, relating to electrical and mechani-
cal performance. In this section other benefits of the 3E
concept are explored. These are perhaps secondary in
nature but still quite important to most all designers of
contemporary power systems and create value for the
end-user as depicted in Figure 14.
The most striking change when comparing a 3E POL
to a more traditional design is the drastic reduction in
the number of passive components used. In addition to
the resultant density enhancements, this reduced parts
count has another significant benefit – higher reliability.
Since the techniques discussed here also will allow for
optimization of system operating efficiency, the average
operating temperature in the 3E POL regulators and other
system components can be lower. Fewer parts operating
at lower temperatures equates to lower failure rate and
higher system MTBF. This in turn leads to reduced sys-
tem maintenance and down time and most importantly, it
leads to fewer site visits and lower total cost of ownership
(TCO) which means higher end-user satisfaction.
The 3E POL regulators are programmable and very flex-
ible, with each part number handling a multitude of differ-
ent input and output voltage combinations. Their ability
to be paralleled allows for a single part number POL to
handle a very wide range of output current if needed.
All this leads to terrific flexibility and system capability
with a relatively few part numbers of 3E POL regulators.
Purchasing volume can be concentrated on a few parts
types for maximum unit cost savings while logistics man-
agement costs are minimized.
Figure 13 The dynamic performance can be improved by reconfiguring the 3E POL regulator for its intended use with a known output capacitance. Using this technique could allow the removal of a significant amount of output capacitance and result in system cost savings.
Output voltage response to load current stepchange (5-15-5 A). Resistive load with slewrate > 7 A/µs at:Tref = +25°C, vl = 12 v, Cout = 470 µF.
Top trace: output voltage (50 mv/div.). Bottom trace: load current (10 A/div.). Time scale: (0.1 ms/div.).
Default robust dynamic configuration Load optimal dynamic configuration
Figure 14 Power supplies with a lower com-ponent count and higher efficiency improve reliability, which in turn reduces the total cost of ownership of the equipment.
Because of the very high flexibility of these 3E products
and the programmable nature of the digital power man-
agement concept, Ericsson Power Modules has realized
the need for a partly different quality assurance
and design/manufacturing verification processes com-
pared to analog products. In addition to the traditional
quality assurance provisions of a hardware manufactur-
ing process, we have instituted stringent controls on the
software and firmware elements associated with this new
manufacturing environment. Ericsson Power
Modules’ approach to these important parts of this
product introduction is discussed in reference (6). The
net result is that usage of these 3E POL regulators will
provide the user with pre-validated products. Compared
with custom designed POL regulator solutions, usage of
the 3E POL regulator will result in substantially reduced
technical risk and shorter time-to-market.
The small physical size of these new products brings
other benefits to the system. The small footprint, in par-
ticular, will be a very big advantage for most users. Board
real estate is a valuable commodity in all end-user equip-
ment and systems. Less board space taken by
POL regulators means more real estate available for
payload circuitry.
The digital power management concept can be a power-
ful tool. While saving a few mW in one small subassembly
may not seem terribly important, the cumulative power
savings in a system of even moderate size can add
up quickly. When several of these systems are oper-
ated many hours a day, the resultant energy savings is
substantial. Building heat load and air conditioning costs
go down. The electrical utility bill goes down. It can be
shown that one watt saved at board level will reduce the
operating energy cost with approximately 10 USD over
a five year period (0.1 USD/kWh). Adding all board level
savings up to the system level will result in substantial
savings of operational expenditures (OPEX) for the end-
user. Fewer natural resources are consumed for power
generation purposes. Everyone wins.
As digital power/energy management becomes more
commonplace it will become an enabling technology, with
ramifications beyond the specific system it is installed in.
It can easily become a powerful tool for the purposes of
data collection and analysis. The result will be increased
knowledge of reliability and failure root cause analysis
that will be invaluable in the design of next-generation
systems.
The above examples are a few ways in which the 3E
POL regulators can enhance the value of your system
and the value of the design experience when using them.
User value is, after all, one of the key elements of the 3E
concept.
The preceding pages have hopefully conveyed much
of the flavor of the 3E concept as applied to these new
POL regulators and what it delivers to the end-user. It
has been shown that the 3 Es provide important ben-
efits – many of them new or best-of-breed for the power
conversion industry:
Enhanced performance
• Significantly higher power and current densities
• Scalable footprint
• Industry-leading efficiency
• Maximum efficiency for all application
• Optimization of dynamic response to actual application
• Excellent feature set for “stand alone” operation
• Flexible fault detection and error handling
Energy management
• Simple and cost-efficient PMBus
• Powerful system development tools
• Many levels of possible power
management methodology
• Unparalleled flexibility during field deployment
• Adaptable systems possible
• Reduced power dissipation
• Reduced energy consumption and utility costs
• Reduced environmental impact
End-User value
• Reduced number of POLs to stock
• Enhanced reliability and higher system availability
• Major advantages during
manufacturing and test
• Increased customer satisfaction
• Comprehensive prevalidation
• Reduced technical risk
• Reduced time-to-market
• More board real estate for payload circuitry
• Enabling technology for data collection and analysis
The list is already a long one, and could be added to.
The reader has probably already thought of other advan-
tages in the end-user equipment that 3E can provide.
To define 3E more succinctly, it is about flexibility - more
importantly, user-defined flexibility. It is about optimization
– namely, user-defined optimization. Past products have
been based on some degree of compromise. Much of
this compromise is no longer required.
3E = Maximal Configurability with Minimal
Compromise
4. 3E – Flexibility and Optimization without Compromise
This brochure has presented several ways in which the
new Ericsson Power Modules 3E POL regulators can be
used to add value to the end-user system while achieving
state-of-the-art performance. Many of these advantages
can be achieved without a commitment to utilize a digital
power management bus in the end application system.
For users who adopt that approach, application of the
3E regulators will be quite similar to using conventional
analog POLs, and the design and testing process will
seem very familiar.
Many users will elect to take advantage of the increased
functionality, flexibility and opportunity for system optimi-
zation that the PMBus offers by using it as an interface
during system development, manufacturing testing or in
the field environment. For some of these users, this will
represent their first power system design using digital
power management techniques. One of Ericsson Power
Modules’ goals is to make the transition from analog to
digital power management systems as convenient as
possible for the end-user by supporting the new products
with a wide variety of applications assistance. In addition
to the references cited earlier in the paper, references (7)
and (8) are recommended as a source of more gener-
alized information about digital approaches to power
conversion design.
The 3E POL regulators are the first Ericsson Power
Modules products containing the PMBus digital interface.
To give the customers an opportunity to easily experience
the benefits to be derived from digital power manage-
ment, a development platform for the 3E POL regulators
is introduced in parallel with the products. This evalua-
tion kit, shown in Figure 15, consists of a demonstration
board with provision for hosting up to 6 pcs of 3E POL
regulators, USB cable, CMM software on CD, device driv-
ers, sample configuration files and complete documenta-
tion. Using this evaluation kit in conjunction with a PC and
commonly available basic lab equipment will allow the
prospective user to conveniently experiment with the digi-
tal development environment. This evaluation kit is highly
recommended as a first step for customers that may be
considering exploring usage of the 3E POL regulators or
designing a power system configured with a PMBus.
The new Ericsson Power Modules 3E POL regulators will
eliminate many of the compromises inherent in current
designs and create exciting opportunities for power sys-
tem designers in terms of system performance, flexibility,
configurability, optimization and end-user value. Further-
more, system design using these products should be a
fun and rewarding experience!
5. Summary
Figure 15 An evaluation kit has been developed to give the customers an opportunity to easily experience the benefits to be derived from digital power management.
ATE Automated Test Equipment
BMPS Board Mounted Power Supply
CD Compact Disk
CMM Configuration Monitoring Management
FPGA Field Programmable Gate Array
FRU Field Replaceable Unit
GUI Graphical User Interface
IBA Intermediate Bus Architecture
IBC Intermediate Bus Converter
IC Integrated Circuit
MicroTCA™ Micro Telecommunications Computing Architecture
MOSFET Metal Oxide Semiconductor Field Effect Transistor
MTBF Mean Time Between Failure
PC Personal Computer
PWB Printed Wired Board
PMBus™ Power Management Bus POL Point of Load
PTH Plated through hole
PWM Pulse Width Modulation
SMT Surface Mount Technology
3E Enhanced Performance, Energy Management, End-user Value
Glossary
All referenced papers can be found at Ericsson Power Modules web site:
http://www.ericsson.com/powermodules
1. Digital Power Forum 2006 – Performance Improvements for OEM System Designers
2. PCIM 2007 – Digital Control Techniques Enabling Power Density Improvements and Power Mgmt Capabilities
3. Digital Power Forum 2007 – Intelligent Energy Management for Improved Efficiency
4. APEC 2007 – Implications of Digital Control and Management for a High Performance Isolated DC/DC
5. Digital Power Europe 2007 – Digital Control in a MicroTCA Power System
6. Digital Power Forum 2007 – Qualification and Verification Considerations for Digital Power Supplies
7. Digital Power Forum 2007 – From Digital Confusion to Digital Conversion
8. Digital Power – Technical Brief
References
Ericsson is shaping the future of Mobile andBroadband Internet communications through its continuous technology leadership.
Providing innovative solutions in more than 140 countries, Ericsson is helping to create the most powerful communication companies in the world.
Ericsson Power Modules is a supplier of world-class DC/DC power modules for distributed power architectures. With its global design, development, manufacturing and sales network Ericsson Power Modules is a leading supplier of power solutions to meet the customer demand for high quality and performance.
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