EE225
TUTORIAL 6
2021
B1. Given Differential Amplifier circuit below, all four transistors are matched. Take β=200.
Choose the suitable value of R to give a source current I = 0.7 mA. Next, take this value of R
and find following:
a) What is the output voltage of the circuit when Vin1=Vin2 and all transistors are active?
b) Show that, Vout 
10
;Vid  Vin1  Vin 2
1  e( 40Vid )
c) By evaluating d(Vout)/dVid at Vid=0, determine differential gain of the amplifier.
d) Calculate input resistance.
+10V
10K
10K
Vout
Vin1
Vin2
I
R
All transistors are 2N2222 or
any same type!
-10 V
EE225
Tutorial: 6
UVM