A GaN Driver IC With Asymmetrical dV/dt Current Clamping Level Shifter and Logic-Based Adaptive Deadtime Control

Gallium-Nitride (GaN) high electronic mobility transistor (HEMT) enables faster switching frequency for buck converters. Therefore, high dV/dt immunity and small deadtime of the switching node become important indicators for GaN-based buck converter. This paper presents a high switching frequency GaN gate driver with an asymmetrical noise current clamping technique for the floating level shifter for 5000V/ns dV/dt noise immunity in simulation and over 60V/ns immunity in measurement. Meanwhile, the proposed deadtime generator achieves adaptive deadtime control without a down level shifter nor fast comparator for sensing operation state of the buck. The proposed driver was implemented in a $0.18\mu $ m BCD process, used in a GaN-based buck converter for verification. It achieves 7.45ns and 1.1ns deadtime for the V_SW trailing and leading edge, respectively. The buck converter obtains 86.5% peak efficiency for 12V-5V conversion, with 10MHz switching frequency.