Nonlinearity of Gm-C in bandpass sigma-delta modulators

Abstract

In this paper, an analysis of nonlinearity in Gm-C filters for bandpass sigma-delta modulators is proposed. Only small cubic non-linear terms are considered. It results in a very simple model of nonlinear resonators. Modeling of an eighth order modulator is also presented. This model is used to predict resonators non-linear effects on the output of a bandpass /spl Sigma//spl Delta/ modulator.