Here's a site where someone plays with balanced line drivers and makes measurments of CCMRR, CDMRR and DCMRR. He shows the formulas relating input and output common mode signals.icthyus said:Maybe someone could explain how you test for it.
CCMRR stands for Common to Common Mode Rejection Ratio. It is a measure of a circuit's ability to reject common mode noise, which refers to signals that are present on both inputs of a differential amplifier.
CCMRR is important because it determines the accuracy and precision of the output signal in a differential amplifier. A high CCMRR value indicates that the circuit is able to reject unwanted common mode noise and provide a more accurate output signal.
CCMRR is calculated by taking the ratio of the differential gain (the gain for differential signals) to the common mode gain (the gain for common mode signals). It is typically expressed in decibels (dB) and a higher value indicates a better rejection of common mode noise.
CCMRR can be affected by a variety of factors including component tolerances, parasitic capacitances, and temperature. Additionally, the layout and design of the circuit can also impact the CCMRR value.
CCMRR can be improved by using well-matched components, minimizing parasitic capacitances, and following best practices for circuit layout. Additionally, using differential amplifiers with a higher gain and lower offset can also improve CCMRR.