High efficiency two‐channel single‐stage switching amplifier with power switches multiplexing.

A two‐channel single‐stage switching amplifier (SSA) based on high‐frequency link inverter is proposed. The audio input signals are modulated by phase shift between primary‐side switches and secondary‐side switches, thus independent amplifications of two channels can be obtained. Benefiting from multiplexing of primary‐side power switches for two channels, only a half bridge inverter is utilised at primary side. Clamp circuits at the secondary side of transformer eliminate spike voltages across the secondary‐side switches during the current commutation of the cycloconverters. Zero voltage switching of primary‐side switches and clamp switches are achieved by utilising magnetising inductor current. A 320 V/250W prototype is presented to verify the analysis results of the proposed two‐channel SSA. [ABSTRACT FROM AUTHOR]