7.2 DIODES 351
(b)
(c)
V
Vo VB
RL 1
Q Q^1
2
Q 3
Q 4
RL 1 < RL 2 < RL 3 < RL 4
VB
V
I
RL 2
RL 3
RL 4
0
0
IQ
VB
Load line
I = (VB − V)/RL
Slope = −1/RL
Device curve
Diode
voltage
Voltage
across
resistor
Load lines
0
Operating (quiescent) point
RL
I
RL
VB
V
I
(a)
+−
+−
Figure E7.2.5(a)Circuit of forward-biased diode.(b)Graphical analysis of forward-biased diode with load
resistance.(c)Graphical analysis for different values of load resistance.(d)Graphical analysis for different
values of supply voltage.(e)Diode circuit with dc and ac sources.(f)Small-signal current and voltage
waveforms.(g)Large-signal current and voltage waveforms.