In a certain digital system there is a requirement for an wi

In a certain digital system there is a requirement for an with a CMR of 80 dB. What is its CMRR?

Solution

The common-mode rejection ratio (CMRR) of a differential amplifier (or other device) measures the ability of the device to reject common-mode signals, those that appear simultaneously and in-phase on both amplifier inputs. An ideal differential amplifier would have infinite CMRR; this is not achievable in practice. A high CMRR is required when a differential signal must be amplified in the presence of a possibly large common-mode input