Compensation of clock feedthrough induced offset in analog adaptive FIR filters based on the LMS algorithm

Abstract

Offset voltage, due clock feedthrough, in the adapting part of analog LMS adaptive filters, causes serious degradation of the filter's convergence and error performance. A compensation scheme and its circuit level implementation is described in this paper. The scheme eliminates the clock-induced offset because the latter is the same for all weight integrators. Computer simulations at both algorithmic and circuit level are presented, which demonstrate the effectiveness of this offset cancellation scheme. J 1 1 1 J J J 1 I