Capacitor-Based Three-Level Gate Driver for GaN HEMT Only with a Single Voltage Supply

Abstract

This paper presents the capacitor based three-level gate driver for Gallium Nitride High Electron Mobility Transistor (GaN HEMT) using only a single voltage supply. The three-level gate driving method is effective to reduce reverse conduction loss of the GaN HEMTs and prevent false turn-on phenomenon in the half-bridge circuit. Conventional implementations require multiple voltage supplies resulting in large circuit area. The proposed gate driver has a capacitor which works as a voltage source to generate negative gate voltage by a single voltage supply. Measurement results of a half bridge circuit show that the proposed three-level gate driver prevents false turn-on and has less reverse conduction loss than a conventional two-level method. Thus, the proposed circuit improves the efficiency of the 48 V input and 12 V/ 4 A output SR-Buck converter by 1.6% compared to the conventional one.