An Up to 10MHz 6.8% Minimum Duty Ratio GaN Driver with Dual-MOS-Switches Bootstrap and Adaptive Short-Pulse Based High-CMTI Level Shifter Achieving 6.05% Efficiency Improvement

Abstract

For future automotive applications, the growing demand for tiny, high power density and fast dynamic response is putting more pressure on power converters, where Gallium nitride FETs have proven to be promising devices [1]. However, for high conversion-ratio GaN power converters, the floating power rail control of half-bridge gate driver and low FOM/high-reliability level shifter (LS) pose a big challenge when increasing switching speed dV/dt and frequency (smaller Ton, min and Toff, min). Charging saturation and over-voltage protection of the bootstrap power supply, as well as common-mode transient immunity (CMTI)/transmission delay/power consumption of LS may introduce efficiency degradation and significant reliability issues.