Four-quadrant flyback converter for direct audio power amplification

This paper presents a bidirectional, four-quadrant flyback converter for use in direct audio power amplification. When compared to the standard class-D switching-mode audio power amplifier with separate power supply, the proposed four-quadrant flyback converter provides simple and compact solution with high efficiency, higher level of integration, lower component count, less board space and eventually lower cost. Both peak and average current-mode control for use with 4Q flyback power converters are described and compared. Integrated magnetics is presented which simplifies the construction of the auxiliary power supplies for control biasing and isolated gate drives. The feasibility of the approach is proven on audio power amplifier prototype for subwoofer applications