Design Voltage Follower

 Design a voltage follower (i.e., ideally voltage gain of 1).

Answer:

Voltage follower that means it follows the input voltage.

So it will be same as input signal voltage. ( Vo = Vin )

so to make this condition we have to make gain = 1 in non-inverting configuration. 

 ( Here we can not use inverting configuration because it is not possible there as its equation is   

 Here -ve sign is there )

so now let us make voltage follower from the non-inverting configuration. 

Put gain A = 1 in equation 

This says that Rfmust be 0 Ω. Practically speaking, that means that Rfis replaced with a shorting wire. 

What about Ri? Theoretically, almost any value will do. As long as there's a choice, consider infinite. Zero divided by infinite is certainly zero. 

The practical benefit of choosing Ri=∞is that you may delete Ri. The resulting circuit is shown in Figure.

This is how we can make voltage follower.