Experimental Investigation on Instability Issues in Parallel-Connected SiC MOSFETs

This paper presents an extensive experimental investigation of oscillatory phenomena of electrical quantities due to the parallel-connection of silicon carbide power MOSFETs. As these phenomena are strictly related to the current imbalance, the analysis focused on the evaluation of the leading causes of instability and their impact. Experimental tests have been performed aiming to analyze the impact of both parameter and layout mismatches, by exploiting static characterization and modulation of the parasitic inductances. Results highlight the correlation between the mismatches and the instability. Finally, some damping strategies, such as decoupling gate resistances and drain-source snubber capacitors, have been considered and tested. This analysis underscores the critical trade-off between instability and reduced performance of power devices.