cmrr
CMRR stands for common-mode rejection ratio. It is a key specification for differential amplifiers, instrumentation amplifiers, and related circuitry that amplifies the difference between two input signals while rejecting signals that appear on both inputs equally. A high CMRR indicates strong suppression of common-mode interference such as power-line hum, ground loops, and other ambient noise, improving measurement accuracy.
The CMRR is defined as the ratio of the differential-mode gain (Ad) to the common-mode gain (Ac):
Measurement of CMRR typically involves applying a known common-mode signal to both inputs while keeping the
Typical values vary by device and frequency. Modern precision instrumentation amplifiers and op-amps commonly report CMRR
Applications include precise sensor interfacing (bridge sensors, strain gauges, thermocouples), biomedical instrumentation (EEG, ECG), and any