An Integrated Gate Driver for E-mode GaN HEMTs with Active Clamping for Reverse Conduction Detection

Detection of reverse-conduction in GaN-based switched-mode power converters is essential to reduce power loss and to protect the circuit from severe undershoot voltage. In this paper, an active clamping SenseFET circuit is proposed to measure the duration that the low-side GaN HEMT is in reverse-conduction and with protection from the high voltage at the switching node. The output of the SenseFET clamping circuit is processed by a custom designed gate driver IC. This IC is fabricated using TSMC's $0.18\ \boldsymbol{\mu} \mathbf{m}$ BCD GEN2 process for driving e-mode GaN power HEMTs with an on-chip closed-loop dead-time correction circuit. The one-step correction mode can optimize the dead-times for both the turn-on and turn-off edges in one switching cycle for switching frequencies of up to 10 MHz with 0.32 ns precision. This allow the power converters to maintain optimal conversion efficiency over the full output current range.

[1]  Dan Kinzer,et al.  GaN power IC technology: Past, present, and future , 2017, 2017 29th International Symposium on Power Semiconductor Devices and IC's (ISPSD).

[2]  Y. Wen,et al.  A GaN HEMT driver IC with programmable slew rate and monolithic negative gate-drive supply and digital current-mode control , 2015, 2015 IEEE 27th International Symposium on Power Semiconductor Devices & IC's (ISPSD).

[3]  Wing-Hung Ki,et al.  A 12A 50V half-bridge gate driver for enhancement-mode GaN HEMTs with digital dead-time correction , 2015, 2015 IEEE International Symposium on Circuits and Systems (ISCAS).

[4]  Bernard H. Stark,et al.  Stretching in Time of GaN Active Gate Driving Profiles to Adapt to Changing Load Current , 2018, 2018 IEEE Energy Conversion Congress and Exposition (ECCE).

[5]  Lenian He,et al.  A GaN HEMTs half-bridge driver with bandgap reference comparator clamping for high-frequency DC-DC converter , 2017, IECON 2017 - 43rd Annual Conference of the IEEE Industrial Electronics Society.