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PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
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Semiconductors and Diodes
McGraw-Hill
1
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.10 i-v characteristic of
semiconductor diode
iD
Reverse
breakdown
region
Reverse
bias
region
Forward
bias
region
_V
Z
V
Complete i-v curve of a
semiconductor diode
McGraw-Hill
2
GIORGIO RIZZONI
vD
+
vD
_
iD
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.20
_
v
+ D
+
_
McGraw-Hill
vi = 155.56 sin t
iD
3
GIORGIO RIZZONI
RL
+
vL
_
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.21 Ideal diode rectifier input and
output voltages
0
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1
0.07
0.08
0.09
0.1
Time (s)
60-Hz source voltage
0
0
0.01
0.02
0.03
0.04
0.05
0.06
Time (s)
Rectified voltage
McGraw-Hill
4
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.29 Diode circuit for illustration of
load-line analysis
RT
vT
iD
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5
GIORGIO RIZZONI
+
vD
_
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.30 Graphical solution of equations
8.13 and 8.14
iD
VT
RT
Q point ( I Q , V Q )
IQ
VQ
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GIORGIO RIZZONI
V
T
vD
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.35 Piecewise linear diode model
iD
Vs
R
Diode off
circuit model
rD
1
rD
V
Diode on
circuit model
Q point
0
0
McGraw-Hill
V
7
GIORGIO RIZZONI
Vs
VD
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.42 Full-wave rectifier
i1
iL
1:2N
+
_
vS
+
Nv S
_
RL
+
vL
_
+
_ Nv S
i2
McGraw-Hill
8
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Volts
Figure 8.43 Full-wave rectifier current and
voltage waveforms
10
10
0
5
–10
0.005 0.01 0.015 0.02 0.025 0.03
0
0.005 0.01 0.015 0.02 0.025 0.03
t (s)
Source voltage
10
Amps
Volts
10
5
0
t (s)
Current i1
0.005 0.01 0.015 0.02 0.025 0.03
5
0
0.005 0.01 0.015 0.02 0.025 0.03
t (s)
Full-wave rectified load voltage
McGraw-Hill
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GIORGIO RIZZONI
t (s)
Current i 2
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.44 Full-wave bridge rectifier
a
D2
D1
c RL d
v S ( t) +_
D4
D3
b
Bridge rectifier
a
AC in
b
IC
Rectifier
c
DC out
d
Corresponding IC package
McGraw-Hill
10
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.45 Operation of bridge rectifier
a
D1
+
v S (t )
_
D4
c RL d
iL
D2
D3
b
During the positive half-cycle of
v S (t), D 1and D 3 are forward-biased
and i L = vS (t )/R L (ideal diodes).
a
+
v S (t )
_
D1
D4
D2
c RL d
iL
D3
b
During the negative half-cycle of
v S (t), D 2 and D 4 are forward-biased
and i L = v S (t ) /R L (ideal diodes).
McGraw-Hill
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GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.49 DC power supply
110 v AC
Line
voltage
+
+
_
v
(t)
AC
_
+
Bridge
rectifier
+
Regulator
vR(t)
_
V DC
Load
_
Filter
Step-down
transformer
McGraw-Hill
12
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.50 Zener diode model for forward
bias
rD
+
_
McGraw-Hill
V
13
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.51 Zener diode model for reverse
bias
rZ
_
VZ
+
McGraw-Hill
14
GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000
PRINCIPLES AND APPLICATIONS OF ELECTRICAL ENGINEERING
THIRD EDITION
Figure 8.53 Complete model for Zener diode
"Forward"
branch
"Reverse"
branch
rD
+
V
_
rZ
_
VZ
+
Complete model
for Zener diode
McGraw-Hill
Circuit
symbol
The Zener diode may be
modeled as consisting of two
parallel branches, representing
forward and reverse operation.
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GIORGIO RIZZONI
© The McGraw-Hill Companies, Inc. 2000