APPARATUS AND METHOD FOR DC OFFSET REDUCTION

摘要

A feedback system has a settling time that is independent of the forward gain of the amplifier stage, and a feedback path that is responsive to the magnitude of DC offset in the output signal. Settling time may be made independent of the forward gain of the amplifier stage by providing a constant loop gain in the amplifier stage through active gain control of both the forward and linear feedback amplifier elements. The feedback path may be made responsive to the magnitude of DC offset in the output signal by providing a non-linear transconductance in the feedback path that varies the high pass corner and hence the DC offset reduction time of the amplifier stage in response the magnitude of DC offset in the output signal.