Download DIODE CIRCUITS - Gunadarma University

RANGAKAIAN DIODA
Hamzah Afandi, Antonius Irianto dan
Betty 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

ID  IS 
VD VT

1
A
 = type of semiconductor factor ( for Si = 2, Ge = 1 )
VT = Volt-Equivalent of Temperature = 25 mV (at 293 oK)
ID
VZ
IS
V
VD
(0.6 - 0.7 for Si)
(0.2 - 0.3 for Ge)
R
Review: p-n Junction
Load-line Concept
+
VAA
R
IDQ
ID
VAA
_
ID
+
_
VD
Quiscent Point
VDQ
VAA
VD
 VAA  R.I D  VD  0
VD


VAA  VD
VT
ID 
 I D  I S  e
 1
R


ID
Analysis of Diode Circuit:
Ideal Diode Approach
_
+
VD
Reverse
ID
Forward/Active
VD
K
A
Diode Circuit:
Simple diode circuit analysis
+5V
1K
+9V
10K
10K
(a)
(b)
-5V
(c)
1K
-9V
(d)
Diode Circuit:
Simple diode circuit analysis
+10V
Q: V12 = ….. ? (D = ON/OFF ?)
2K
R3
R1
V1
V2
D
2K
R2
4K
R4
6K
Assumption that Diode is OFF
R2
2K
V1 
10 
10  5V
R1  R2
2K  2K
R4
6K
V2 
10 
10  6V
R3  R4
4K  6K
V12  V1  V2  5  6  1V  0
Diode is CORRECTLY OFF!
Diode Circuit:
A LOGIC GATE
+5V
RS
0V
+6V
VI
VO
D1
RL
VI
VO
+6V
0V
+5V
0V
Diode Circuit:
A LOGIC GATE
VB
+5V
+6V +6V
0V +6V
+6V 0V
0V 0V
RS
D1
+6V
VA
VO
RL
VB
+6V
D2
VA
VO
+5V
0V
0V
0V
Diode Circuit:
Clipping Circuit
R1
Vi
Vo
20V
D
20V
+
10V
10V
Diode Circuit:
Clipping Circuit
R1
Vi
Vo
20V
D
+
10V
20V
-10V
Diode Circuit:
Clipping Circuit
R1
Vi
Vo
20V
D1
D2
+
20V
10V
10V
10V
-10V
Diode Circuit:
Diodes as Rectifiers
(Half Wave Rect.)
Vo
D
RL
VDC
1

2

Vm
Vm

0 Vm sin  d  2  cos 0  
Diode Circuit:
Diodes as Rectifiers
(Full Wave Rect.)
D1
Vo
RL
VDC
1
2
2

D2
2Vm
2Vm

0 Vm sin  d  2  cos 0  
Diode Circuit:
Diodes as Rectifiers
(Full Wave Rect.)
Vo
D1
D2
D3
D4
RL
VDC 
2Vm

Diode Circuit:
Diodes as Rectifiers
(Full Wave Rect. + Filter)
Vo
D1
D2
D3
D4
RL
C
VDC  Vm
Diode Circuit:
Diodes as Rectifiers
(Voltage Regulator Concept)
Vr (rms)
%r  %ripple factor 
100
VDC
Vr = Ripple Voltage (RMS),
VDC = DC Output Voltage
VNL  VFL
%VR  %Voltage Re gulation 
100
VFL
VNL = DC Voltage at no-load
VFL = DC Voltage at full-load
Diode Circuit:
Vi
Peak Detectors
D
C
R
VO
Diode Circuit:
Vi
AM Demodulator
D
C
R
Vo
Diode Circuit:
Voltage Doubler
2VSP
_
Vi
+
VO = 2 VSP
D2
C1
VSP
+
D1
C2
+
_
Diode Circuit:
Switching Flyback
+Vs
+Vs
i
_
+
+Vs
i=0
VC
L
v
L
v
L
+
_
t
VSW
D
SW
SW
SW
t
C
+
_
Diode Circuit:
Flyback Prevention
+Vs
+Vs
i
_
+
i
L
D
L
D
_
SW
+
SW
Analysis of Diode Circuits:
Large-Signal Model
(Piecewise Linear Approach)
ID
ID=(VD-V )/RF
1/Rf
VZ
IS
1/Rr
ID=(VD/RR) - IS
V
VD
Analysis of Diode Circuits:
Large-Signal Model (Piecewise Linear)
A
A
A
A
Rf
IS
Rr
V
K
K
K
ID=(VD-V )/RF
Forward-Biased Diode
(On)
K
ID=(VD/RR) - IS
Reversed-Biased Diode
(Off)
Analysis of Diode Circuits:
Characteristic Transfer Curve Method
R1
vo
Vo
D
20V
+
1/Rf
10V
vi
10V
20V
Vi
1/Rr
Analysis of Diode Circuits:
Using PWL & Characteristic Transfer Curve
Solve For:
vi
D1
5K
vO
10
t
+
5K
D2
-10
5V
5V
CALCULATION
EXAMPLES
Given in class