Estimating Semiconductor Switch Temperature in Automotive Applications Using DeSat Voltage

Abstract:
A cost-effective method for estimating the junction temperature of semiconductor switches in automotive traction applications is proposed, utilizing the desaturation (DeSat) voltage sensing of a high-voltage isolated gate driver. By leveraging the existing DeSat protection mechanism, this approach eliminates the need for additional temperature sensors, reducing cost and design complexity while ensuring accurate thermal monitoring. Experimental validation under various operating conditions confirms the effectiveness of the method, demonstrating its potential for real-time integration into automotive inverters. Furthermore, the proposed technique enables fault detection and lifetime degradation monitoring of semiconductor switches, enhancing system reliability and protection.