RANGAKAIAN DIODA

Hamzah Afandi, Antonius Irianto danBetty Savitri

Sources: Millman, Jacob, Grabel, Arvin, Microelectronics,

Mc. Graw Hill Int. Ed., 1994.Robert Boylestad, Louis Nashelsky Sixth Edition; Prentice Hall,1997

Review: p-n Junction

Volt-Ampere Characteristic of Diode

A 1 TD VVSD II

= type of semiconductor factor ( for Si = 2, Ge = 1 )VT = Volt-Equivalent of Temperature = 25 mV (at 293 oK)

VD

ID

ISVZ

V (0.6 - 0.7 for Si) (0.2 - 0.3 for Ge)

Review: p-n Junction

Load-line Concept

VD

ID

IDQ

VDQ

VAAR

VAA

Quiscent Point

VD

+

_

ID+

_VAA

R

1

0.

T

DV

V

SDDAA

D

DDAA

eIIR

VVI

VIRV

Analysis of Diode Circuit:

Ideal Diode Approach

VD

ID

VD

+ _

ID

Forward/ActiveReverse

AA

KK

AA

KK

AA

KK

AA

KK

AA

KK

Simple diode circuit analysis

Diode Circuit:

+5V

1K

+9V

10K

-9V

1K

-5V

10K

(a) (b) (c) (d)

Simple diode circuit analysis

Diode Circuit:

+10V

2K

2K

4K

6K

R1

R2

R3

R4

D

Q: V12 = ….. ? (D = ON/OFF ?)

V1 V2

VKK

K

RR

RV 610

64

610

43

42

VKK

K

RR

RV 510

22

210

21

21

01652112 VVVV

Diode is CORRECTLY OFF!

Assumption that Diode is OFF

A LOGIC GATE

Diode Circuit:

+5V

RS

RL

D1

VI VO+6V0V

VI VO

+6V +5V 0V 0V

VA

VB

+6V

+6V

A LOGIC GATE

Diode Circuit:

+5V

RS

RL

D1

VO

VB VO

+6V +6V +5V

D2

VA

0V +6V 0V+6V 0V 0V

0V 0V 0V

Clipping CircuitDiode Circuit:

+

10V

R1

D20V

Vi

20V

Vo

10V

Clipping CircuitDiode Circuit:

+

10V

R1

D20V

Vi

20V

Vo

-10V

Clipping CircuitDiode Circuit:

+

10V

R1

D1

20V

Vi

10V

D2 20V

Vo

10V

-10V

Diodes as Rectifiers (Half Wave Rect.)

Diode Circuit:

RL

D

Vo

VmVm

dVmVDC 0

0

cos2

sin 2

1

Diodes as Rectifiers (Full Wave Rect.)

Diode Circuit:

RL

D1

Vo

D2

VmVm

dVmVDC

2cos

2

2sin

2

12 0

0

Diodes as Rectifiers (Full Wave Rect.)

Diode Circuit:

Vo

D1 D2

D3 D4

RL

Vm

VDC

2

Diodes as Rectifiers (Full Wave Rect. + Filter)

Diode Circuit:

Vo

D1 D2

D3 D4

RL C VmVDC

Diodes as Rectifiers (Voltage Regulator Concept)

Diode Circuit:

100)(

%% DC

r

V

rmsVfactorrippler

100Re %%

FL

FLNL

V

VVgulationVoltageVR

Vr = Ripple Voltage (RMS),VDC = DC Output Voltage

VNL = DC Voltage at no-loadVFL = DC Voltage at full-load

Peak DetectorsDiode Circuit:

R

D

C

Vi

VO

AM DemodulatorDiode Circuit:

R

D

C

Vi

Vo

Voltage DoublerDiode Circuit:

D2C1

D1 C2

+VSP

Vi VO = 2 VSP

2VSP

+_

+_

Switching FlybackDiode Circuit:

+Vs

i = 0

+

_

v

+Vs

i+

_

v

+Vs

C

+_

VSW

t

VC

t

SW SW SW

D

LLL

Flyback PreventionDiode Circuit:

+Vs

+

_

i

+Vs

+

_i

SWSW

DL

DL

Analysis of Diode Circuits:

Large-Signal Model (Piecewise Linear Approach)

VD

ID

ISVZ

V

1/Rf

ID=(VD-V )/RF

1/Rr

ID=(VD/RR) - IS

Analysis of Diode Circuits:

Large-Signal Model (Piecewise Linear)

Rf

Forward-Biased Diode (On)

Reversed-Biased Diode (Off)

V

RrIS

ID=(VD-V )/RF ID=(VD/RR) - IS

A

KK

A

K

A

K

A

K

Analysis of Diode Circuits:

Characteristic Transfer Curve Method

+

10V

R1

D20V

Vi

20V

Vo

10V

vi

vo

1/Rr

1/Rf

Analysis of Diode Circuits:Using PWL & Characteristic Transfer Curve

Solve For:

+

5V

5K

D1

D2

5V

vO

5K

t

vi

10

-10

CALCULATIONEXAMPLES

Given in class