A Capacitor-Based Multilevel Gate Driver for GaN HEMT Only with a Single Voltage Supply

This paper presents a capacitor-based multilevel gate driver for GaN HEMTs. The proposed gate driver suppresses false turn-on and reduces the reverse conduction loss with a single voltage supply. It has a capacitor which operates as a negative voltage supply to pull the gate terminal instantly to suppress false turn-on and then the gate terminal goes back to 0 V to reduce the reverse conduction loss with RC discharge. The proposed and conventional gate drivers are implemented on a 48V-to-12V synchronous buck converter. At 500 kHz and 24 W, efficiencies of the proposed and conventional gate drivers are 93.6% and 86.7% respectively. With the proposed gate driver at 48 W, the peak of ringing due to turning on of high-side switch is 0.45 V.