A hybrid power amplifier using 3-phase 3-level class-D with 200nH inductors and current balancing technique

A hybrid power amplifier (PAhybrid), combining class-D and class-AB amplifier is demonstrated. As a specific structure for class-D, 3-level and 3-phase (3P3L) techniques are applied to reduce the current ripple to 1/12th of that of standard 2-level class-D amplifier. At the same time, the effective switching frequency increases by 6 times. Compared to the previous works which use several uH inductors, this paper only uses 200nH inductors with comparable efficiency, showing 30% increase in the proposed figure-of-merit (FOM).