Principles of Analog Electronics

Principles of Analog Electronics

426

➜ The parameter

h

i

v

ob

c

cb

i

e

=

=

0

can often be negligible since it is related to the poor slope of the BJT’s output

characteristics within the active region.

The AC analysis will here be performed according to Figure 11.49 (the analysis

for Figure 11.50 is similar to that already performed in Section 11.5.2).

Before determining the circuit’s equations, it is useful to recall the formulas of

the h–parameter network, which are useful to model the AC behavior of the BJT

when it operates in C.B. conguration in the center of the forward-active region

(Section11.3.2):

h

vhihveqICB

ihihve

eb ib erbcb

cfbe ob cb

−

=+

=+

(...