An adaptive output impedance gate drive for safer and more efficient control of Wide Bandgap Devices

Abstract

This paper presents an adaptive gate drive circuit to provide a safer and more efficient control of Wide Bandgap Devices (WBD). The gate drive circuit fabricated in AMS0.35μm HV CMOS technology has an adaptive output impedance for optimal turn-on/off driving conditions and a gate side power transistor switching transition detection. Its impedance can be precisely adjusted from 0.7Ω to 12.5Ω during transition time accordingly to the switched current to reduce overvoltage due to parasitic inductances. It can also be set to maintain the same transition times of WBD over operating point and temperature variations. Therefore, in an 800 kHz switching frequency synchronous buck converter based on WBD, the proposed gate drive circuit demonstrates secure but drastic dead-time reduction with a peak performance gain of 20% compared to a fixed dead-time of 50ns.