Question

Define Common-Mode Rejection Ratio (CMRR).

Answer 1

Answer:

The op amp common-mode rejection ratio (CMRR) is the ratio of the common-mode gain to differential-mode gain. For example, if a differential input change of Y volts produces a change of 1 V at the output, and a common-mode change of X volts produces a similar change of 1 V, then the CMRR is X/Y.

Explanation:

CMRR is the ratio of differential gain and the common mode gain. For ideal op-amp, the value of CMRR is infinite, but for practical op-amp's the value of CMRR used to be in the range of 80 to 100 dB.