Power Factor Correction using an Enhancement-mode SiC JFET

The conventional wisdom that the SiC HET is a normally on device has recently been superseded by the first practical normally off SiC HET. The new true enhancement mode, three-terminal, pure-SiC design provides designers with a normally off solution that retains all the benefits of the normally on SiC JFET. With a simple change in the series gate impedance, the EM SiC JFET can be used with common IC drivers and is a drop-in replacement for current power devices in most applications. Device characteristics are superior to MOSFETs and IGBTs and offer the possibility of efficiency improvements from reduced conduction and switching losses. The work presented in this paper demonstrates the drop-in replacement of an IGBT with a normally off SiC HET in a PFC demo circuit. System efficiency using each device was observed and compared. An improvement was noted with the HET as expected.