Semiconductor Concepts Back Up 2

7/24/2019 Semiconductor Concepts Back Up 2

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ELECTRONICS course outline

By : Eng’r. Red



SEMICONDUCTOR CONCEPT

Intrinsic Semiconductor

The term intrinsic here distinguishes

between the properties of pure"intrinsic" silicon and the dramaticallydierent properties of doped n-type orp-type semiconductors.

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/dope.html






SEMICONDUCTOR CONCEPT At any temperature above absolute zero temperature,

there is a finite probability that an electron in the lattice will beknocked loose from its position, leaving behind an electron

deficiency called a "hole".

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/sili.html





Both electrons and holes contribute to current flow in an intrinsic

semiconductor.

If a voltage is applied, then both the electron and the hole can

contribute to a small current flow.

Semiconductor Current



The current flow in an intrinsic semiconductor is influenced by the

density of energy states which in turn influences theelectron density in the conduction band. This current is highly

temperature dependent.


The current which will flow in an intrinsic semiconductor consists

of both electron and hole current.

Semiconductor Current

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/fermi.html






Electrons and Holes


In an intrinsic semiconductor like silicon at temperatures above

absolute zero, there will be some electrons which are ecited across

the band gap into the conduction band and which can produce

current.


http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/band.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/band.html




Energy Bands for Solids




Silicon Energy Bands

At finite temperatures, the number of electrons which reach the

conduction band and contribute to current can be modeled by the

!ermi function. That current is small compared to that in

doped semiconductors under the same conditions.


http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/intrin.html









Germanium Energy Bands

"!ermi level" is the term used to describe the top of the collection

of electron energy levels at absolute zero temperature.



Silicon and Germanium


olid state electronics arises from the uni#ue properties of silicon

and germanium, each of which has four valence electrons and which

form crystal lattices in which substituted atoms $dopants% can

dramatically change the electrical properties.






ilicon is by far the more widely used semiconductor for electronics,

partly because it can be used at much higher temperatures than

germanium.

Silicon




&ermanium will at a given temperature have more free electrons

and a higher conductivity.

Germanium




Silicon Lattice

ilicon atoms form covalent bonds and can crystallize into aregular lattice.

The actual crystal structure of silicon is a diamond lattice.

This crystal is called an intrinsic semiconductor and can

conduct a small amount of current.

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/sili2.html





http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/sili2.html



Silicon Crystal Structure


ilicon crystallizes in the same pattern as diamond, in a structure which

Ashcroft and 'ermin call "two interpenetrating face(centered cubic" primitive

lattices.

http://hyperphysics.phy-astr.gsu.edu/Hbase/minerals/diamond.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/minerals/diamond.html



The illustration shows the arrangement of the silicon atoms in a unit cell,

with the numbers indicating the height of the atom above the base of the

cube as a fraction of the cell dimension.




The Doping of Semiconductors


The addition of a small percentage of foreign atoms in the regular

crystal lattice of silicon or germanium produces dramatic changes in

their electrical properties, producing n(type and p(type

semiconductors.






Valence Electrons

The electrons in the outermost shell of anatom are called valence electrons;



Examples of acceptor atom

1. oron2. Aluminum. #alium

Trivalent impurities

Impurity atoms with * valence electrons produce p(type

semiconductors by producing a "hole" or electron deficiency.






-Type Semiconductor


The addition of pentavalent impurities such as antimony,

arsenic or phosphorous contributes free electrons, greatly

increasing the conductivity of the intrinsic semiconductor .

hosphorous may be added by diffusion of phosphine gas

$*%.





P- !unction


/ne of the crucial keys to solid state electronics is the

nature of the (0 1unction. 2hen p(type and n(type materials

are placed in contact with each other, the 1unction behaves

very differently than either type of material alone.

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/sselcn.html





http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/sselcn.html



+illing a !ole ma,es a negati)e ion and lea)es 'e!ind

a "ositi)e ion on t!e n#side. - s"ace c!arge 'uilds u"&

creating a de"letion region (!ic! in!i'its any %urt!er

electron trans%er unless it is !el"ed 'y "utting a

%or(ard 'ias on t!e $unction.


/ITI45 I/0 !6/'

65'/4A7 /! 5758T6/0

05&ATI45 I/0 !6/'

!I77I0& /! 3 T95

4A8A089

/755758T6/0

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/pnjun2.html





Bias effect on electrons in depletion #one

-n a""lied )oltage in t!e for$ard direction as

indicated assists electrons in o)ercoming t!e coulom'

'arrier o% t!e s"ace c!arge in depletion region.

%&"'("D B)(S




- reverse voltage dri)es t!e electrons a(ay %rom t!e

$unction& "re)enting conduction.

"EVE"SED B)(S




%or$ard Biased P- !unction

electrons and !oles com'ine at t!e $unction so

t!at a continuous current can 'e maintained.






re)erse )oltage across t!e "#n $unction (ill cause a

transient current to %lo( as 'ot! electrons and !oles are

"ulled a(ay %rom t!e $unction.

!en t!e "otential %ormed 'y t!e (idened de"letion layer euals t!e a""lied )oltage& t!e current (ill cease e*ce"t

%or t!e small t!ermal current.

"everse Biased P- !unction

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/pnjun.html










!or a p(n 1unction at e#uilibrium, the fermi levels match on the two

sides of the 1unctions.

5lectrons and holes reach an e#uilibrium at the 1unction and form a

depletion region.


P- Energy Bands









P- Energy Bands


To forward bias the p(n 1unction, the p side is made more

positive, so that it is "downhill" for electron motion across the

1unction.

The conduction direction for electrons in the diagram is right to left,

and the upward direction represents increasing electron energy.






%or$ard Biased Conduction

the electrons in the n(type material have been elevated and

diffusion across the 1unction occurs.

At a higher energy than the holes in the p(type







SEMICONDUCTOR DIODE

The P- !unction Diode

T!e nature o% t!e "#n $unction is t!at it (ill conduct current in

t!e %or(ard direction 'ut not in t!e re)erse direction.

T!e 'asic $unction diode ma,es use o% a "#n $unction toac!ie)e recti%ication and is (idely used %or t!at a""lication.


http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/diod.html


http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/rectifiers.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/rectifiers.html






HO S!M"O# O$ % DIODE %S DERI&ED '

C%THODE

(

%NODE

%

%CTU%# COMPONENT

IC%TES TH%T THIS SIDE IS % C%THODE ) (

%NODE

SEMICONDUCTOR DIODE



SEMICONDUCTOR DIODE



Type of Diodes

SEMICONDUCTOR DIODE



The *ener Effect

it! t!e a""lication o% su%%icient re)erse )oltage& a

"#n $unction (ill e*"erience a ra"id a)alanc!e 'rea,do(n

and conduct current in t!e re)erse direction.

SEMICONDUCTOR DIODE







SEMICONDUCTOR DIODE

Tunnel Diode The tunnel diode has a region in its

voltage current characteristic where the current decreases

with increased forward voltage, known as its

negative resistance region.

This characteristic makes the tunnel diode useful inoscillators and as a microwave amplifier.

Schematic s*m+ol

S CO C O O

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/zener.html






SEMICONDUCTOR DIODE

Tunnel 0iode C!aracteristic

The negative resistance region of the tunnel diode makes

oscillator action possible.

The uni1unction transistor has a similar oscillator application.

SEMICONDUCTOR DIODE


http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/unijun.html


http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/relaxo.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/relaxo.html






SEMICONDUCTOR DIODE

find application as rectifiers for high fre#uency signals.

$unction of lightly dopedn-type semiconductor witha metal electrode.

The 1unction of a doped semiconductor $usually n(type%

with a metal electrode can produce a very fast(switching.

used in high fre#uency circuits or high speed digitalcircuits.

Schematic s*m+ol

Schott+y Diode





SEMICONDUCTOR DIODE



SEMICONDUCTOR DIODE

1aractor Tuner electronic tuning circuits, as in television tuners.

The :8 control voltage varies the capacitance of the

varactor, retuning the resonant circuit.

SEMICONDUCTOR DIODE

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/electric/parres.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/electric/parres.html



SEMICONDUCTOR DIODE

Light Emitting Diode Structure

75:s are p(n 1unction devices constructed of gallium arsenide

$&aAs%, gallium arsenide phosphide $&aAs%, or gallium phosphide

$&a%.

SEMICONDUCTOR DIODE





SEMICONDUCTOR DIODE

LE0 C!aracteristics

SEMICONDUCTOR DIODE



LE0 Radiation 2atterns

The typical radiation pattern shows that

most of the energy is emitted within +;< of

the direction of maimum light.

ome packages for 75:s include

plastic lenses to spread the light for a

greater angle of visibility.

SEMICONDUCTOR DIODE

SEMICONDUCTOR DIODE



Electroluminescence in LE0s

SEMICONDUCTOR DIODE

light is produced by a solid state process called electroluminescence.

SEMICONDUCTOR DIODE

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/led.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/led.html



SEMICONDUCTOR DIODE

T!e Organic LE0 3 OLE0 4

/75: is a device that consists of two or three layers of materials oforganic molecules or polymers .

/75: produce light thru the process of electrophosphorescence.

/75:s typically emit less light per unit area than inorganic solid(

state based 75:s which are usually designed for use as point(light

sources.

8an be used in television screens, computer monitors, small, portablesystem screens such as mobile phones and :As, watches,

advertising, information and indication.

SEMICONDUCTOR DIODE



SEMICONDUCTOR DIODE

OLE0 3 Organic LE0 4

SEMICONDUCTOR DIODE



SEMICONDUCTOR DIODE

7arge :isplay screen formed by many 6&B piels.

iel is greatly eaggerated for illustration.

SEMICONDUCTOR DIODE



Searc! %or a Blue LE0

After a decade of intense research, a bright blue 75: was

successfully produced by 0ichia 8hemical of 5a"an in 6778.

The material used for the diode was gallium nitride &a0.

0ichia has also produced an In&a0 laser diode which lases in the

blue(violet region of the spectrum.

SEMICONDUCTOR DIODE

Blue 75:s are important for the development of high(information(

density storage on optical disks.

itachi and 'atsushita have taken this approach to producing

blue light for optical disks and digital versatile disks $:4:%.



SEMICONDUCTOR DIODE



SEMICONDUCTOR DIODE

Laser 0iodes

"#n $unction %ormed 'y t(o do"ed gallium arsenide layers.

SEMICONDUCTOR DIODE





SEMICONDUCTOR DIODE

T!e 2IN 0iode

The I0 diode has heavily doped p(type and n(type regions separated by

an intrinsic region.

It acts like an almost constant capacitance reverse biased

It behaves as a variable resistor forward biased .

It is used in microwave switching applications.

TR%NSISTOR









THE OR0 T"(S)ST&" )S ( C&T"(CT)& &%

,C""ET-T"(S%E"")G "ES)ST&"./

TR%NSISTOR

TR%NSISTOR



TR%NSISTOR

The Bipolar !unction Transistor 0 B!T 1

consists o% t!ree regions o% do"ed semiconductors.

DI$$ERENT (INDS TR%NSISTOR





DI$$ERENT (INDS TR%NSISTOR

TR%NSISTOR



t!e most !ea)ily do"ed o% t!e t!ree semiconductor regions o% a

B5T.

Emitter

Collector

T!e largest o% t!e t!ree semiconductor region s o% a B5T

Base

T!e 'ase is )ery t!in and lig!tly do"ed com"ared to t!e t(o

regions.

TR%NSISTOR

TR%NSISTOR



Transistor &peration

- transistor in a circuit (ill 'e in one o% t!ree conditions:

6. Cut o%% 3no collector current4& use%ul %or s(itc! o"eration.

9. -cti)e region use%ul %or am"li%ier a""lications.

. Saturation large current use%ul %or ;s(itc! on; a""lications.

TR%NSISTOR

TR%NSISTOR

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/transwitch.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/trans.html



http://hyperphysics.phy-astr.gsu.edu/Hbase/solids/trans.html




Transistor &peration

TR%NSISTOR



TR%NSISTOR



T!e analogy to a )al)e is sometimes !el"%ul& t!e smaller current

in t!e 'ase acts as a ;)al)e;& controlling t!e larger current %rom

collector to emitter.

- ;signal; in t!e %orm o% a )ariation in t!e 'ase current is

re"roduced as a larger )ariation in t!e collector#to#emitter current&

ac!ie)ing an am"li%ication o% t!at signal.

TR%NSISTOR

N P N

TR%NSISTOR



TR%NSISTOR

P N P

TR%NSISTOR



Constraints on Transistor &peration

TR%NSISTOR

TR%NSISTOR CON$I-UR%TION



P Common Emitter (mplifier The common emitter configuration lends itself to voltage

amplification and is the most common configuration for

transistor amplifiers.





P Common Collector (mplifier

/ften called an emitter follower since its output is taken

from the emitter resistor.

Is useful as an impedance matching device since its input

impedance is much higher than its output impedance.

It is also termed a "buffer " for this reason and is used in

digital circuits with basic gates.


http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/gate.html






TR%NSISTOR "I%SIN-



DC Bias

Esta'lis!es t!e dc o"erating "oint 3 < "oint 4 %or "ro"erlinear o"eration o% transistor as an am"li%ier.

It is use to esta'lis! a steady le)el o% transistor current and

)oltage .

In order %or t!e transistor to o"erate "ro"erly as

am"li%ier & t!e t(o 2#N $unctions 3BC and BE $unctions4

must 'e correctly 'iased (it! e*ternal dc )oltages.

TR%NSISTOR "I%SIN-



TR%NSISTOR "I%SIN-



'4 Nonlinear o"eration : out"ut )oltage limited 3cli""ed4 'y cuto%%.

E$$ECTS O$ IMPROPER "I%SIN-

-m"li%ier

TR%NSISTOR "I%SIN-

TR%NSISTOR "I%SIN-



c4 Nonlinear o"eration : out"ut )oltage limited 3cli""ed4 'y saturation.

E$$ECTS O$ IMPROPER "I%SIN-

-m"li%ier

TR%NSISTOR "I%SIN-

5?NCTION +IEL0 E++ECT TR-NSISTOR



2. !unction %ield Effect Transistor 0!%ET1

- is a uni"olar , )oltage#controlled device in which current flows from the

Source to the 0rain. It uses an induced electric %ield to control current.

( the value of the drain to source voltage of a !5T at which the drain

current becomes constant when the gate 3 to 3 source voltage is zero.

3. Pinch - off - voltage

( the area near a p(n 1unction on both sides that has no ma1ority carriers.

4. Depletion region




5. Drain

( one of the three terminals of a !5T analogous to the collector of a B>T.

6. Channel

( the conductive path between the source and the drain.

( one of the three terminals of a !5T analogous to the base of a B>T.

7. Gate

8. Source

( one of the three terminals of a !5T analogous to the emitter of a B>T.




N @ c!annel 5+ET Construction

+igure - s!o(s t!e cross section o% a 5unction +ET 35+ET4




I% 1GS and 10S are 'ot! /ero )olts t!e transistor is not

conducting. 3 o%% 4

+or normal o"eration t!e 10S is a'out 6.8 to 6.= )olts

1GS control t!e %lo( o% drain current

5unction +ield E%%ect Transistor 35+ET 4 O"eration




'or a gi(en (alue of the

current is (ery nearly constant. no chan,e / o(er a wide range of(oltages ) &

DS *.

+ary from let say 0v to 1v

-ate volta,e2 0& . &

drain currentID Source)to)Drain%

ID 3 no chan,e

4& 5& 1&

$4& set at ;4 ? 4: is varied from ;4 to * 4%

5+ET CH-R-CTERISTIC

C?R1E




/hen the is made morenegati(e ) - * suppose draincurrent ) 0 * for a gi(en (alue of

(oltage )&DS

*.

Su66ose &DS set at 4&

-ate volta,e 0&to )4&

Source)to )Drain

4&

ID ,oes

do7n

ID

$4& varied from ;4 to (=4? 4ds set at =4%

5+ET CH-R-CTERISTIC C?R1E




5+ET O"eration Belo( ;2inc! O%%;




5+ET O"eration -'o)e ;2inc! O%%;




(PPL)C(T)& 9

6. ?sed in LC0 tec!nology

one "i*el

$ET

one pixel

Optical Micrograph of TFT Array

#i8uid cr*stal cell

.emits li,ht /

Note9 There are millions of pixel inan

Circuit o%




:igh Po$er %ETs

+ETs used in !ig! "o(er out"ut stages are o%ten seen re%erred to as

1AOS& 0AOS or TAOS.

T!ese transistors are 'asically t!e same as ot!er IG+ETs 'ut !a)es"eciali/ed constructions t!at allo( t!em to "ass currents as large as

6>-.

T!ey are also a'le to s(itc! on and o%% )ery uic,ly 3in nano

seconds4 (!ic! allo(s t!em to 'e used in suc! circuits as s(itc!

mode "o(er su""lies (!ere )ery %ast s(itc!ing is essential.

(PPL)C(T)& S9




En!ancement Aode AOS+ET

T!e Insulated Gate +ET 3IG+ET4

T!e Aetal O*ide Silicon +ET 3AOS+ET4 or Aetal O*ide Silicon

Transistor 3A.O.S.T.4 !as an e)en !ig!er in"ut resistance 3ty"ically

6>69 to 6>6 o!ms4 t!an t!at o% t!e 5+ET.

Gate is com"letely insulated %rom t!e rest o% t!e transistor 'y a )ery

t!in layer o% metal o*ide 3Silicon dio*ide SiO9

4. Hence called IG+ET or

Insulated Gate +ET.




Construction of a Channel Enhancement ;ode ;&S%ET




Enhancement ;ode &peration

T!e gate !as a )oltage a""lied to it t!at ma,es it "ositi)e (it! res"ect tot!e source.




0e"letion mode AOS+ET

Reducing T!e Conduction C!annel

The depletion mode '/!5T shown as a 0 channel device $ channel is

also available% in fig below is more usually made as a discrete

component, i.e. a single transistor rather than I8 form.

De6letion Mode N Channel MOS$ET




&peration of a Depletion ;ode ;&S%ET

In the 0 channel device, gate is made negative with respect to the

source, which has the effect creating a depletion area free from charge

carriers, beneath the gate. This restricts the depth of the conducting channel, so increasing

channel resistance and reducing current flow through the device.




AOS+ET #Terminal

The 'etal /ide emiconductor !ield 5ffect Transistor $'/!5T%

builds upon the basic !5T by adding a layer of silicon dioide

It achieves etremely high input impedance, in the range =;@

to =;= ohms.

E#ECTRONIC CIRCUITS

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/fet.html

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/fet.html



Diode (pplications

6ectification

8lamper

A' detection

8lipper

!' detection

4oltage :oubler

0IO0E AO0ELS



2ROBLEA NO. 6

+IG?RE 6 #

0IO0E AO0ELS



SO#UTION 9

0IO0E AO0ELS



H%#$ : %&E RECTI$IER



64 Recti%iert!e a'ility o% a diode to con)ert alternating current 3-C 4

to "ulsating direct current 30C4.

Sc!ematic diagram o% Hal%#a)e Recti%ier

DIODE %PP#IC%TION

E#ECTRONIC CIRCUITS



Hal%#a)e Recti%ier

E#ECTRONIC CIRCUITS



Center#Ta" +ull#a)e Recti%ier

E#ECTRONIC CIRCUITS



Bridge Recti%ier

E#ECTRONIC CIRCUITS



Current +lo( in t!e Bridge Recti%ier

E#ECTRONIC CIRCUITS



"ipple for "C %ilter

T!e rms ri""le )oltage %or an RC %ilter can 'e

a""ro*imated 'y

and t!e 0C out"ut le)el 'y

RC $I#TER



"ipple for "C %ilter

E#ECTRONIC CIRCUITS



";S "ipple Voltage

0IO0ES



T2IC-L 0IO0E 2-CD-GES

+ORA?L-S RECTI+IERS



+ORA?L-S RECTI+IERS



RECTI+IERS



RECTI+IERS

2ROBLEA NO. 9

!igure * ( =

RECTI+IERS



RECTI+IERS

SOL?TION

RECTI+IERS



RECTI+IERS

2ROBLEA NO.

+igure 9 # >

RECTI+IERS



RECTI+IERS

SOL?TION

>.>= or .= F

LIAITERS



- circuit (!ic! remo)es t!e "ea, o% a (a)e%orm is ,no(n

as a clipper .

LIAITERS



2ROBLEA NO. 8

SO#UTION 9

LIAITERS



O?T2?T -1E+ORA

LIAITERS



LIAITERS



2ROBLEA NO.

LIAITERS



SO#UTION

+IG?RE 9 # 86

CL-A2ERS OR 0C RESTORERS



clamp a peak of a waveform to a specific :8 level compared with a

capacitively coupled signal which swings about its average :8 level $usually

;4%.

If the diode is removed from the clamper, it defaults to a simple coupling

capacitor3 no clamping.




2ROBLEA NO.




SO#UTION

ENER 0IO0E



2ROBLEA NO.

SOL?TION :

'igure 3

ENER 0IO0E



2ROBLEA NO.

SOL?TION :

ENER 0IO0E



2ROBLEA NO. =

SOL?TION :

E#ECTRONIC CIRCUITS



*ener "egulator Design

One a""roac! to ener regulator design is to consider

t!e desired load current and t!e amount o% ri""le "resent in

t!e a)aila'le unregulated su""ly.

E#ECTRONIC CIRCUITS

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/zenereg.html






T!e "o(er rating o% t!e load resistor must 'e at least

and t!e "o(er rating o% t!e /ener diode must 'e

Note: ou may su'stitute )alues %or t!e /ener )oltage& t!e in"ut

)oltage& t!e ri""le )oltage or ri""le %actor& and t!e load resistor.

1OLT-GE A?LTI2LIER



A voltage multiplier is a specialized rectifier circuit producing an output which istheoretically an integer times the A8 peak input.

$for eample, +, *, or times the A8 peak input.%

To get +;; 4:8 from a =;; 4peak A8 source using a doubler, ;; 4:8 from a

#uadrupler.

1OLT-GE A?LTI2LIER



1OLT-GE A?LTI2LIER



H-L+ -1E 1OLT-GE 0O?BLER

1OLT-GE A?LTI2LIER



but

"* (&#

Therefore

1OLT-GE A?LTI2LIER



1OLT-GE TRI2LER

1OLT-GE <?-0R?2LER

TR-NSISTOR BI-SING



Transistor C!aracteristic Cur)es

3-""ro*imate %or 9N99994

TR-NSISTOR BI-SING



Transistor Load Line

3-""ro*imate %or 9N99994

Transistor Load Line determination

TR-NSISTOR BI-SING



Transistor Load Line determination

TR-NSISTOR BI-SING



P T"(S)ST&" (;PL)%)E" B)(S)G

TR-NSISTOR BI-SING



2ROBLEA NO. 7

'igure 4 -5

TR-NSISTOR BI-SING



TR-NSISTOR BI-SING



etermine the bias parameters for the (oltage di(ider circuit shown.

2ROBLEA NO. 6>

TR-NSISTOR BI-SING



0C eui)alent

TR-NSISTOR BI-SING



1oltage 0i)ider 'ias Emitter sta'ili/ed 'ias

TR-NSISTOR BI-SING



Collector %eed'ac, 'ias Base 'ias

TR-NSISTOR BI-SING



Emitter %eed'ac, 'ias

0C LO-0 LINE



0C O2ER-TING 2OINT



< 2OINT IS TOO CLOSE TO

THE S-T?R-TION 2OINT

< 2OINT IS TOO CLOSE TO

THE C?T O++ 2OINT

0C O2ER-TING 2OINT



TR-NSISTOR -C -N-LSIS



The tas6 of an audio ampli7er is to ta6e a small signal and ma6e itbigger without ma6ing any other changes in it.

a musical sound usually contains se(eral fre8uencies, all of whichmust be ampli7ed by the same factor to a(oid changing thewa(eform and hence the 8uality of the sound.

An ampli7er which multiplies the amplitudes of all fre8uencies bythe same factor is said to be linear.

epartures from linearity lead to (arious types of distortions.




Harmonic 0istortion

It can arise if any component in the amplifier clips the peaks of the

waveform.




Intermodulation Distortion

0on(linearity in amplifier components causes miing of fre#uency

components to form components at sum and difference fre#uencies.

articularly troublesome in the reproduction of music because it

generates fre#uencies which were not present in the original musicand are thus very noticeable.




A E9:%+AE;T &' T<E %;!:T =T.




r @ "arameter model 3s!aded

'loc,4 connected to e*ternal

circuit




>odel circuit forobtaining ac (oltage gain

! # "arameters



S?AA-R O+ +ORA?L-S +OR B5T



COAAON EAITTER




COAAON EAITTER


COAAON EAITTER



COAAON EAITTER




COAAON COLLECTOR




COAAON B-SE

COA2-RISON O+ -C and 0C Load Line



CL-SS B -A2LI+IER



Transformer coupled push 3 pull amplifiers C= conducts during the

positive half cycle ? C+ conducts during the negative half cycle. The

two halves are combined by the output transformer.

CL-SS B 2?SH # 2?LL -A2LI+IER



CL-SS C -A2LI+IER



0-RLINGTON 2-IR



SIDL-I 2-IR



0-RLINGTON 2-IR



Darlin,ton Com6lementar* Darlin,ton

Class %" %m6li<er

?@i6lai pair

A?LTI ST-GE -A2LI+IER G-INS



AvT D Av= Av+ Av* E.Avn

in dB, AvdB D +; log AvT

Av $dB% D Av$=dB % F A v$+dB % F E. Avn$dB%

G''A69 /! :I!!5650T A'7I!I56 8/0!I&G6ATI/0



!unction %ield Effect Transistor

$IE#D E$$ECT TR%NSISTOR



$IE#D E$$ECT TR%NSISTOR



OP ) %MP



O"erational -m"li%iers

The term operational amplifier or "op(amp" refers to a class of

high(gain :8 coupled amplifiers with two inputs and a single output.

The Ideal O6)am6

=. Infinite voltage gain

+. Infinite input impedance

*. Hero output impedance

. Infinite bandwidth

). Hero input offset voltage $i.e., eactly

zero out if zero in%.

OP ) %MP



Real )s Ideal O"#am"

Rationale for Ne,ative $eed+ac=

OP ) %MP



Rationale for Ne,ative $eed+ac=

It helps to overcome distortion and nonlinearity.

It flattens fre#uency response or allows you to tailor it to a desired fre#uency

response curve.

It makes properties predictable, less dependent on temperature

manufacturing differences or other internal properties of the active device

. 8ircuit properties are dependent upon the eternal feedback network and

are thus easily controlled by eternal circuit elements.

8ircuit design can concentrate on function and not the details of operating

point selection, biasing, and the other details characteristic of discrete transistor

amplifier design.

Practical "ene<ts of Ne,ative $eed+ac=

OP ) %MP



Sta+ili>ation of &olta,e -ain

gain with negative feedback is

This stabilization increases the

effective bandwidth.

where is the fraction of theoutput which feeds bac6 as anegati(e (oltage at the input.

OP ) %MP



Increasin, In6ut Im6edance

in>

Decreasin, Out6ut Im6edance



0ecreasing 0istortion (it! +eed'ac,



:istortion reduction takes the form below for this amplifier,showing that distortion within the feedback loop is

discriminated against, with more reduction of distortion which

arises near the output.

Increasing t!e Band(idt!



In)erting -m"li%ier

OP ) %MP



!or an ideal op(amp, the inverting amplifier gain is given simply by

Non#in)erting -m"li%ier

OP ) %MP



!or an ideal op(amp, the non(inverting amplifier gain is given by

Summing -m"li%ier

OP ) %MP



g "

Aore t!an t(o in"uts can 'e used& %or e*am"le in an audio

mi*er circuit.

T!e in"ut resistors can 'e uneual& gi)ing a (eig!ted

sum.



OP ) %MP

-n o"#am" )oltage %ollo(er can ser)e as a 'u%%er.

http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/opampvar2.html




-n o" am" )oltage %ollo(er can ser)e as a 'u%%er.

The basic emitter follower

can be used as a buffer.

Buffer used for impedance matching and for isolation of the inputand output.

OP ) %MP

Integrator


http://hyperphysics.phy-astr.gsu.edu/Hbase/electronic/npncc.html






Integrator

OP ) %MP

0i%%erentiator



1 t i th t f h f th t t lt i

OP ) %MP



1. etermine the rate of change of the output (oltage in

response to the 7rst input pulse in a pulse wa(eform asshown for the integrator in the 7gure . The output (oltage isinitially @ero.

B +

c C .1u '

D C 1 =ohm

d& dt 3 ) &in R i C

OP ) %MP



&ne input is grounded and the and the signal (oltage isapplied to the other input.

OP ) %MP



+ o

Two opposite polarity ) out of phase * are applied to the inputs.

OP ) %MP



Two signals of the same phase fre8uency and amplitudeare applied at the inputs.

OP ) %MPCARR



The measure of amplifier ability to re1ect common

mode signals.

In dB



?&:T%&;F



OP ) %MP

IN2?T IA2E0-NCE



rential input impedance - input resistance between in(erting and non in(ertin

ommon mode input impedance - resistance between each inputand the ground.

OP ) %MP

INPUT : O$$SET CURRENT



OP ) %MP

?E/ DATE G the maximum rate of change of the outputl i i l



(oltage in response to input (oltage.

/hereF

OP ) %MP

!roblem F



OP ) %MP

?&:T%&;F



?&:T%&;F

OP ) %MP

!D&E>F



2hen a pulse is applied to an op 3 amp , the output goes from

3 4 to F 4 in ;.) us. 2hat is the slew rateJ

OP ) %MP

In6ut O?set volta,e )



- small dc (oltage appear at the output when nodierential (oltage is applied.

OP ) %MP

OPEN #OOP -%IN +elo7 critical fre8uenc*.-%IN &S@ $REAUENC!/



A

OP ) %MP

!roblemF



OP ) %MP

?&:T%&;F



OP ) %MP

Pro+lem9



OP ) %MP



OP ) %MP

!roblemF



?&:T%&; F



OP ) %MP

!roblemF



!roblemF

OP ) %MP



OP ) %MP



$I#TERS

#O P%SS $I#TER



At c C D

$I#TERS

HI-H P%SS $I#TER



At c C D

$I#TERS

"%ND P%SS $I#TER



.HH

1

"%ND STOP $I#TER

$I#TERS



-ENER%# DI%-R%M O$ %CTI&E $I#TER

$I#TERS



R4

R5

$I#TERS



$I#TERS

SIN-#E PO#E %CTI&E HI-H P%SS $I#TER and $RAUENC! RESPONSE



SIN-#E PO#E %CTI&E HI-H P%SS $I#TER and $RAUENC! RESPONSE

OSCI##%TOR

SCI##%TOR ) is a circuit that 6roduces a 6eriodic 7aveform on its out



7ith onl* DC su66l* volta,e as an in6ut

"asic elements of feed+ac=oscillator

OSCI##%TOR

POSITI&E $EED"%C(



OSCI##%TOR



1. The phase shift around the loop must eecti(ely .

2. The (oltage gain A around the closed

feedbac6 loop )loop gain * must e8ual 1 unity

OSCI##%TOR



OSCI##%TOR



OSCI##%TOR

CONDITIONS $OR ST%RT UP %ND SUST%INED OSCI##%TION



OSCI##%TOR



OSCI##%TOR

CO#PITTS OSCI##%TOR



Desonant fre8uency aectedby loading

OSCI##%TOR

CO#PITTS OSCI##%TOR



'igure 13 - 21

OSCI##%TOR

A!! &?%AT&D



onditionI

OSCI##%TOR

H%RT#E! OSCI##%TOR



onditionI

To ensure oscillation 2 %& 3 #5 #4

%& B 4 "

OSCI##%TOR



%RMSTRON- OSCI##%TOR

OSCI##%TOR



OSCI##%TOR

CRST-L OSCILL-TOR



OSCI##%TOR

INTERN%# DI-R%M O$ TIMER



TIMER CONNECTED as %ST%"#E MU#TI&I"R

OSCI##%TOR



OSCI##%TOR

TIMER CONNECTED as %ST%"#E MU#TI&I"R%



t <

&O#T%-E RE-U#%TOR

LINE REG?L-TION



No signi%icant

c!ange in

out"ut )oltage

!roblemF

&O#T%-E RE-U#%TOR



SO#UTION9



!roblemF

&O#T%-E RE-U#%TOR



&O#T%-E RE-U#%TOR

Load regulation @ "ercentage c!ange in t!e out"ut )oltage %or

a gi)en c!ange in load current.



&O#T%-E RE-U#%TOR

!roblemF



=. A certain regulator has a =+ 4 output when there is no load . $ I7 D ;A% 2hen

there is a full 3 load current of =; mA , the output is ==.@ volt. 5press

regulation as a percentage change from no ( load to full load and also as a

percentage change for each mA change in load current.

&O#T%-E RE-U#%TOR



he load regulation can also be expressed as a percentage change per milliamp

/here 1 mA is change in current from no load to full load.

&O#T%-E RE-U#%TOR

Th i i l t



R$# smallest rated load resistance

Thevenin e8uivalentcircuit for a 6o7ersu66l* 7ith a loadresistor@

& out

&TH 3 &$#

&O#T%-E RE-U#%TOR



&O#T%-E RE-U#%TOR

SERIES RE-U#%TOR



SERIES RE-U#%TOR

&O#T%-E RE-U#%TOR



&O#T%-E RE-U#%TOR

SERIES RE-U#%TOR



&O#T%-E RE-U#%TOR

SHUNT RE-U#%TOR



SHUNT RE-U#%TOR 7ith #oad resistor

&O#T%-E RE-U#%TOR



SHUNT RE-U#%TOR

&O#T%-E RE-U#%TOR

Semiconductor Concepts Back Up 2

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Transcript of Semiconductor Concepts Back Up 2