Self oscillating switch mode power amplifiers are known to be susceptible to interchannel disturbances also known as crosstalk. This phenomenon has a significant impact on the performance of an amplifier 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 amplifier (class D). A step by step reduction of elements in an amplifier 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 filter has a major impact on the level of crosstalk.
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