Higher the value of RE, more is the negative feedback and less is the common mode gain. To increase CMRR, emitter resistance RE should be increased. Ideally, the CMRR should be infinite and practically it should be as high as possible.Īnswer: CMRR is the ratio of differential voltage gain (Ad) to the common mode voltage gain (Ac), so we can improve the CMRR by either increasing differential voltage gain or by decreasing common mode voltage gain. It is called as a figure of merit of a differential amplifier. What is common mode rejection ratio (CMRR)?Īnswer: Common mode rejection ratio is the ability of a differential amplifier to reject the common mode signals successfully. Single input unbalanced output differential amplifier.Single input balanced output differential amplifier.Dual input unbalanced output differential amplifier.Dual input balanced output differential amplifier.Depending on the way of connecting the input to them and depending on the way of measuring output, there are four configurations of differential amplifier, they are: Answer: A differential amplifier consists of two transistors.
