Abstract: A differential amplifier embodying the invention includes a differential stage whose total output current is sensed and whose "tail" and output current is maintained relatively constant over a large common mode voltage range by means of a current feedback loop. This feature eenables the differential amplifier to accurately amplify low amplitude signals riding on a very large common mode signal. The tail current to the differential amplifier is supplied by a controllable current source. The tail current flows via two differentially connected transistors in two differential output terminals and is divided between them as a function of the voltage applied to two differential signal input terminals. The amplitude of the tail current is set by a current level setting current source connected to a summing node. An amplifier and current mirroring network is connected between the summing node and the controllable current source.