THD+Noise Estimation in Class-D Amplifiers

Abstract

A mathematical analysis of the effect of jitter and nonlinear inductance on THD+noise of class-D amplifiers is presented. In the analysis, it is assumed that jitter is not correlated between edges and has Gaussian distribution. It is shown that the nonlinear inductor in the output filter causes THD+noise to be frequency dependent. The relationship between jitter, nonlinear inductor and circuit parameters is formulated. The accuracy of the proposed mathematical approximation is verified by transistor level simulations.