
Principles of Analog Electronics
446
ANSWER
I
BQ
≅ 40 μA, I
CQ
≅ 3.2 mA, V
CEQ
≅ 5.5 V.
EXERCISE 6
Determine the stability factors S
I
CBO
, S
V
BEQ
, S
β
of the amplier of the previous
exercise.
ANSWER
≅≅
µ
β
SS
35,0.28, 17.3
IV
CBOBEQ
.
EXERCISE 7
Consider the collector-feedback bias amplier as already schematized in
F igure 11.63 .
Find the I
CQ
–V
CEQ
pairs in quiescent conditions when V
CC
= 12 V, R
C
= 2 kΩ,
and R
F
= 47 kΩ, for the two occurrences β = 80 and β = 120.
ANSWERS
AV V4.38
.13
CQ CEQ
4.738
.46
CQ CEQ
Observation
Higher β corresponds to higher I
CQ
but lower V
CEQ
, and thus a higher drop on R
C
.
EXERCISE 8
A four-resistor bia ...