Differential amplifier with current source controlled through differential feedback

摘要

A differential amplifier (10) includes a first electrical path (14) formed between a first transistor (M1) and a first load impedance (Z1); a second electrical path (15) formed between a second transistor (M2) and a second load impedance (Z2); a tail-current transistor (M3) coupled to the first and second transistors; an input end of a feedback amplifier (16) coupled directly to the first and second electrical paths (14, 15) for receiving a differential voltage output signal; and an output end of the feedback amplifier coupled directly to the tail-current transistor (M3) for adjusting the current provided through each of the first and second electrical paths. The feedback amplifier (16) includes a non-inverting input node and an inverting input node, each node coupled directly to one or the other of the first and second electrical paths.