Finite Gain Differential Amplifiers:
In the 3-port VCVS of Figure, if a potential divider is added at the input, the circuit of Figure is achieved for which we get :
V1 = (R4/ R3 + R4) e1
Combining Eqs. (58) and (53), we get
V0 = ( 1+ (R2/R1) /( 1+ (R3/R4) e -( R2 /R1) V2
Figure: Finite Gain Differential Amplifier
Letting R2 /R1 = (1+ (R2/R1) /(1+ (R3/R4) - K
The circuit realizes a K-gain differential amplifier for which the needed resistor values are found to be
R2 = k R1, R4 = KR3