
Principles of Analog Electronics
396
➜ Resistance
is between the BJT collector terminal and the ground, and
parallel to resistance
.
➜ The signal source, with its internal resistance, is between the BJT base termi-
nal and the ground, so in parallel with resistance
.
Observation
The battery, considered an ideal source of constant voltage, has zero resistance
(Figure 4.3c in Chapter 4).
As a result, the equivalent AC model layout looks like the signals shown in
Figure 11.29.
This conguration is conrmed to be a C.E. as the emitter is evidently shared
between the AC input and output loops.
Before determining the circuit’s equations, it is usefu ...