Improved Gate-Voltage-Driven Desaturation Short-Circuit Protection Circuit With Robust Switching Noise Immunity for WBG Power Semiconductors

Abstract

Wide bandgap (WBG) power semiconductors are used in numerous power conversion applications because of their excellent switching characteristics. However, it is difficult to ensure short-circuit protection for WBG power semiconductors because of their shorter short-circuit withstand time. The fast-switching characteristics of WBG power semiconductors induce severe fluctuations in the drain-source voltage and drain current in switching transients, which results in the false triggering of the protection circuit. Therefore, the fast response speed and switching noise suppression are key requirements of the protection circuit for a WBG power semiconductor. To meet these requirements, an improved gate-voltage-driven desaturation protection circuit with a fast response speed and robust noise immunity is proposed in this study. The effect of switching noise on the proposed protection circuit is analyzed, and a detailed design procedure based on the analysis results is provided. The experimental results indicate that the protection delay of the proposed circuit is within 91 ns; in addition, the proposed circuit can survive switching noise during normal operation. Finally, the noise immunity analysis results are verified through experiments under various protection circuit parameter sets.