A 0.00043% THD+N 50W Class D Audio Amplifier GaN-Power Stage with High Frequency Residual Cancellation and Anti-Reverse Techniques

This paper proposes a 50W Class D audio amplifier GaN power stage. Due to the reduction of reverse conduction and hard switching losses in the GaN power stage, the proposed antireverse (AR) technique achieves a peak efficiency of $\mathbf{9 4 \%}$, higher than comparable technologies for MOSFET power switches. In addition, due to the low parasitic capacitance and low onresistance of GaN power switches, the operating frequency can be increased to high switching frequencies. Additionally, the proposed high frequency residual cancellation (HFRC) technique can reduce the $\mathrm{THD}+\mathrm{N}$ to approximately 0.00043% at 1kHz input.