An 87% peak efficiency, 37W, class H audio amplifier with GaN output stage

Abstract

This paper presents a novel high output power class H audio amplifier design with GaN transistors output stage. The design is implemented in 0.18-μm BCD process. Several design techniques to drive the GaN output stage and to improve the efficiency of the class H amplifier are introduced in this paper. The design consumes 706.3mW quiescent power and can deliver up to 37W peak output power to the load of 32Ω with the peak power efficiency of 87%. This design achieves the lowest THD+N ratio of -70.17dB.