A New Approach to Validate GaN FET Reliability to Power-Line Surges Under Use-Conditions

Abstract

The robustness of FETs to power-line surges has a tremendous impact on field reliability and is an important consideration for the adoption of new technologies like GaN. The methodology for silicon FETs, however, is not suitable for GaN because of the low avalanching energy capability of present-day GaN FETs. However, GaN FETs have better transient overvoltage capability than Si FETs, providing the ability to operate through surge without avalanching. This paper defines, for the first time, a methodology for the surge rating of GaN FETs using their superior transient overvoltage capability. It leads to a device-level surge parametric specification, an important consideration for the design of surge-robust power supplies using GaN. GaN FETs are shown to be robust to power line surges under actual operating conditions for the first time. This seminal work results in a comprehensive methodology for surge-robust power supply design with GaN.