A non-inverting amplifier is built with a feedback fraction

PHYSICS · Multi-part · Fermi University Physics · Electronics, Instrumentation & Communication · Feedback, operational amplifiers and analogue signal processing · Feedback, operational amplifiers and analogue signal processing

Electronics for Measurement, Ch The operational amplifier and negative feedback

Problem

\beta = 0.05

, so its target closed-loop gain is

1/\beta = 20

. The operational amplifier's datasheet quotes an open-loop gain

A_{\rm OL}

of at least

6\times10^4

and typically

3\times10^5

. ((a)) Calculate the loop gain

T = A_{\rm OL}\beta

and the closed-loop gain

A_{\rm CL}

at the minimum open-loop gain. ((b)) Calculate the fractional gain error

1/(1+T)

at this minimum, and state by how much the closed-loop gain falls short of

20

Browse the problem library