Investigation of crosstalk in self oscillating switch mode audio power amplifier

Self oscillating switch mode power ampliers are known to be susceptible to interchannel disturbances also known as crosstalk. This phenomenon has a signicant impact on the performance of an amplier of this type. The goal of this paper is to investigate the presence and origins of crosstalk in a two channel self oscillating switch mode power amplier (class D).

A step by step reduction of elements in an amplier built for this task, is used for methodically determining the actual presence and origins of crosstalk. The investigation shows that the crosstalk is caused by couplings in the self oscillating pulse width modulation circuits, but also that the output lter has a major impact on the level of crosstalk.