Self-Adjusting Deadtime Generator for High-Efficiency High-Voltage Switched-Mode Power Amplifiers

In this paper, we propose a novel design methodology for a deadtime generator for high-efficiency power amplifiers. It consists of a two-phase non-overlapping clock circuit and level down shifters. A 3% improvement in efficiency is achieved with a maximum efficiency of 94% in a class-D power amplifier circuit. The proposed design generates a deadtime as low as 16.7ns and eliminates the problem of propagation delay mismatch between high side and low side gate drivers. The circuit is implemented in 50V AMS 0.35 μm CMOS technology. The deadtime generator consumes 16.5 mW, while occupying a total area of 0.068 mm
²
.