Gate Drive Concept for dv/dt Control of GaN GIT-Based Motor Drive Inverters

Abstract

In high-volume applications like home appliance motor drives, system cost and density are key value metrics. In many cases, system packaging puts severe limits on the power dissipation ability of the power electronics, so inverter losses must be kept to a minimum. GaN power transistors can offer significant improvements in power loss compared to IGBT or MOSFET-based inverters [1], [2], but controlling switching speed (dv/dt) can be challenging.This paper proposes a simplified active dv/dt control method that can be integrated into the driver IC and GaN transistor using low-cost techniques without adding passive components or bondwires inside the Integrated Power Module (IPM). The circuit is implemented in a monolithic 3-phase gate driver IC using low-cost 0.35 μm HVJI CMOS process. The package- integrated 3-phase inverter using the IC with 6 discrete GaN GIT is demonstrated to be capable of delivering 226 W from a 12x12 mm package, about double the power delivered by today’s silicon-based inverter in the same package size.The results of simulation and experiment are provided for an integrated IPM driving a motor load up to 226 W.