Threshold Voltage Drift in GaN Power Modules under Mass Production Evaluation and Solution to Overcurrent Protection Failure

Speaker： Zihao Zhang

Location:  SIST 1A-200

Time：     2nd July. 2026 16:00

Host:         Prof. Minfan Fu

Abstract:

Threshold voltage (Vth) drift in GaN HEMTs remains a major reliability barrier for mass-produced power modules, causing latent and unpredictable failures in critical power conversion functions such as over-current protection (OCP) during startup, in critical applications such as data center Hybrid Switched Capacitor (HSC) converters. While device-level solutions exist, there remains a certain gap between these solutions and their practical application in large-scale commercial production.

This talk explores a converter-level framework to estimate and mitigate voltage-drift issue at scale. It quantitatively describes the impact of device threshold voltage drift on circuit behavior. Crucially, it proposes using the output charge integral during a fixed detection plateau as a circuit-observable proxy for drift. By evaluating the soft-start parameters, it enlarges the safety margin to prevent over-current protection failures. Experimental validation on 6,000+ modules shows a failure rate reduction to 0.05% (from 3.1% baseline) after parameter adjustment. This work enables cost-effective, software-only reliability enhancement for GaN-based power modules in industrial deployment.

Biography:

Zihao Zhang received his B.S. degree in electrical engineering from Shandong University, Jinan, China, in 2024. He is currently working toward the M.S. degree in power electronics with the School of Information Science and Technology, ShanghaiTech University, Shanghai, China.His recent research interests include the application of wide bandgap semiconductors in data center power supply.