Question

Can the voltage gain of a follower stage be equal to 1?

(a) Yes, by increasing the transconductance

(b) No

(c) Yes, by modifying the bias voltage

(d) Yes, by modifying the bias current

This question was posed to me in an interview for job.

Asked question is from MOSFET Amplifier with CD Configuration topic in section FET Amplifiers of Analog Circuits

Answer 1

The correct choice is (b) No

For explanation I would say: From the expression of voltage gain, we find that if the voltage gain is 1, the transconductance has to be infinite which is practically impossible. However, we can reach a voltage gain of approximately equal to 1 but never equal to 1.