A 99%-efficiency 1-MHz 1.6-kW zero-voltage-switching boost converter using normally-off GaN power transistors and adaptive dead-time controlled gate drivers

A zero-voltage-switching (ZVS) boost converter using normally-off GaN power transistors and an on-chip gate driver are presented in this paper. The ZVS and adaptive dead-time control are developed to minimize the capacitive switching loss and body-diode recovery loss of the boost converter. Both high-side and low-side gate drivers provide ~6.8-ns propagation delays and ~2-ns rise/fall time, enabling MHz operation of the converter. With the proposed on-chip adaptive dead-time controlled gate drivers implemented in a 0.35-μm high-voltage CMOS process and 600-V normally-off GaN power transistors, the proposed 400-V ZVS boost converter delivers an output power of 1.6 kW and achieves a peak power efficiency of 99.2% at 1-MHz switching frequency.