1. 2012 final-term examination (120)
Electronic Circuits
Date: December 10, 2012.
1. Consider the following CE amplifier circuit. (100)
1) Calculate the equivalent Thevenin circuit ( V BB , R BB ) for the base of Q1 in terms
of a DC bias circuit. (20)
2) Calculate the bias condition ( I C , VCE ) for the above circuit for
V BE = 0.7V , β = 150 . (20)
3) Present the hybrid Π model for Q1. (10) Hint:) VT = 25 [mV]
4) Get the AC gain [dB] ( A = V0 / Vi ) when capacitors are shorted. (20)
5) Calculate the impedance of capacitors, CC1, CC2, CB when f = 1 [kHz]. (10)
What is the meaning of this small impedance? (10) Hint:) Z c =
1
jωC
6) Suggest how to increase the voltage VCE when VCC is fixed. (10)
2. Design an operational amplifier with AV = +50 . (10) What is the output voltage
when vi = 2 [mV]. (10)
![2012 final-term examination (120)
Electronic Circuits
Date: December 10, 2012.
1. Consider the following CE amplifier circuit. (100)
1) Calculate the equivalent Thevenin circuit ( V BB , R BB ) for the base of Q1 in terms
of a DC bias circuit. (20)
2) Calculate the bias condition ( I C , VCE ) for the above circuit for
V BE = 0.7V , β = 150 . (20)
3) Present the hybrid Π model for Q1. (10) Hint:) VT = 25 [mV]
4) Get the AC gain [dB] ( A = V0 / Vi ) when capacitors are shorted. (20)
5) Calculate the impedance of capacitors, CC1, CC2, CB when f = 1 [kHz]. (10)
What is the meaning of this small impedance? (10) Hint:) Z c =
1
jωC
6) Suggest how to increase the voltage VCE when VCC is fixed. (10)
2. Design an operational amplifier with AV = +50 . (10) What is the output voltage
when vi = 2 [mV]. (10)](https://image.slidesharecdn.com/testec20122-131016012052-phpapp01/85/2012-2-1-320.jpg)
