Charge domain bit-serial multiplying digital-analog converter

摘要

A single chip adaptive filtering system including an FIR filter and circuitry for calculating updated weighting coefficients for use in associated multiplying digital-to-analog converters. The adaptive FIR filter performs the convolution of a delayed and sampled input sequence to produce a filter output. Thereafter, an error term is determined by calculating the difference between the filter output and a reference signal which corresponds to a predetermined anticipated output of the filter. The error term is then applied to a least mean square (LMS) estimation algorithm for computing updated weighting coefficients to be used by the adaptive FIR filter.