Question

The object of this problem is to investigate the effects of finite open-loop gain, finite input 

impedance, and nonzero output impedance of the op-amp on the voltage follower.

The circuit, including the op-amp model, is shown in the figure.

(A) . Derive an expression for the circuit voltage gain vo/vs. 

Evaluate for and  

Compare this result to the gain with an ideal op-amp.

(B). Derive an expression for the circuit input impedance Zin=vs/is. 

Evaluate for  

Compare this result to the input impedance with an ideal op-amp.