
Principles of Analog Electronics
386
Our rst C.E. conguration is illustrated in Figure 11.17.
We have a DC source
CC
that biases the transistor to work in its active region, a
sinusoidal voltage source
s
for input, a load resistor
L
for output, and the BJT is
a silicon npn-type with output characteristic curves as represented in Figure 11.18.
To operate in class A conditions (Section 10.2.4 in Chapter 10), we require a
Q-pointapproximately in the middle of the active region.
Amplier's
FIGURE 11.16 Analysis to perform the study of an amplier.
I
B
= 125 μ
150 μA
175 μA
200 μA
225 μA
30
20
10
0
0510 15 20
V
CE
[V ]
C
FIGURE 11.18 Output character