Constant-Current Gate Driver for GaN HEMTs Applied to Resonant Power Conversion

Abstract

New semiconductor technology is enabling the design of more reliable and high-performance power converters. In particular, wide bandgap (WBG) silicon carbide (SiC) and gallium nitride (GaN) technologies provide faster switching times, higher operating temperature, and higher blocking voltage. Recently, high-voltage GaN devices have opened the design window to new applications with high performance and cost-effective implementation. However, one of the main drawbacks is that these devices require accurate base current control to ensure safe and efficient operation. As a consequence, the base drive circuit becomes more complex and the final efficiency is decreased. This paper presents an improved gate driver circuit for GaN devices based on the use of a constant current regulator (CCR). The proposed circuit achieves constant current regardless of the operating conditions, solving variations with temperature, aging and operating conditions that may degrade the converter performance. Besides, the proposed circuit is reliable and cost-effective, being applicable to a wide range of commercial, industrial and automotive applications. In this paper, its application to a zero-voltage switching resonant inverter for domestic induction heating was performed to prove the feasibility of this concept.