Silicon carbide JFET reverse conduction characteristics and use in power converters

Abstract

Recent advances have resulted in the availability of a new generation of silicon carbide (SiC) junction field effect transistors (JFETs), which unlike previous generations, exhibit highly desirable normally off characteristics. Normally off SiC JFETs are characterised with particular focus on previously unknown reverse conduction characteristics. Refinements are proposed to JFET gate driving circuits that allow their implementation as a single-chip solution. Reverse recovery characteristics of SiC JFETs were measured using diode testing techniques and found to be significantly faster than typical silicon metal oxide semi-conductor field effect transistor (MOSFET) body diodes. SiC JFETs are compared with silicon MOSFETs in power factor correction boost converters, including a real-world application where superior power conversion efficiency utilising SiC JFETs is demonstrated.