An optimal design method of delta-sigma modulator for class-D audio amplifier

Abstract

The class-D audio amplifer using delta-sigma(ΔΣ) modulation technique has been spotlighted recently. In order to obtain a high performance class-D amplifer, the order of the ΔΣ modulator needs to be higher as much as possible. However the design of high-order ΔΣ modulator is very difficult because of necessity of optimal parameter setting with keeping system stability. In this paper, we propose a new design algorithm that decides an optimal design solution, and guarantees the system stability. Our approach saves the design time of the ΔΣ modulator enormously compared with the conventional method.