Tutorial 2
1.
Calculate VCE, IC and IB for the circuit in Figure E3. Given ß = 100 and VBE = 0.7V.
+ 25V
RB1
220 k
+ 9V
RC
6 k
RB
100 k
RB2
470 k
RE
2.5 k
RE
1.5 k
Figure E3
Rajah E4
2.
Determine VC, VB and VE for a voltage feedback biasing circuit if RB = 470k, RC = 4k
, VCC = 22V, RE = 200, ß = 200 and VBE = 0.7V.
3.
Obtain RB needed for a voltage feedback biasing circuit to give an operating point at ICQ =
4.35mA and VCEQ = 1.6V. Given VCC = 30V, RC = 5.5k, RE = 1k and ß = 180. Assume
VBE = 0.7V.
4.
Determine the biasing current and voltage for the circuit in Figure
Given ß = 45 and VBE = 0.7V.
5.
Find R1 and R2 of a voltage divider circuit that has been simplified to a circuit shown in
Figure E5. Assuming VBE = 0.5V, obtain the Q-point for the circuit if (a) ß = 80 and (b) ß
= 160. What can be said about the operating point of the transistor with a 100% change in
ß?
+ 28V
15 k
10 k
1 k
1.6V
Figure E5
E4.