Performance Comparison of Traditional and JBS Integrated SiC MOSFETs in Si/SiC Hybrid Switch

The Si/SiC hybrid switch concept of paralleling a main Si IGBT and an auxiliary SiC MOSFET offers an improved cost/performance tradeoff in power converters. However, high reverse drop voltage and potential degradation of body diode in SiC MOSFET lead to high power loss and reliability problems of Si/SiC hybrid switches. To inhibit body diode conduction, the junction barrier controlled Schottky rectifier integrated silicon carbide MOSFET (SiC JMOS) in replacement of traditional silicon carbide MOSFET in the Si/SiC hybrid switch is proposed. In this work, the static and dynamic characteristics of the Si/SiC hybrid switch with SiC JMOS (JMOS pair) and the Si/SiC hybrid switch with traditional SiC MOSFET (DMOS pair) are measured and compared. The results show that JMOS pair has lower reverse conduction voltage drop, better reverse recovery performance and smaller turn-on switching losses than DMOS pair. Then a single-phase H-bridge VSI is built to compare the efficiency and thermal performances between the two hybrid pairs. Experimental results show that JMOS pair solution can achieve maximum 0.2% higher conversion efficiency and maximum 5°C lower case temperature of power switches than DMOS pair solution in same condition.