AC-coupled gate driver with gate current switch under single power supply for normally-off SiC JFET

摘要

Theoretically, normally-off silicon carbide (SiC) junction field-effect transistors (JFETs) do not require a negative gate voltage supply because they are in an off-state when the gate-source voltage is 0 V. However, most gate drivers for normally-off SiC JFETs require not only a positive power supply for turning on the JFET but also a negative power supply for turning it off and maintaining a negative gate-source voltage to suppress a false turn-on power loss caused by crosstalk during fast switching. Therefore, modifications of gate drivers increase complications and costs. In this study, a normally-off SiC JFET gate driver, which can be realized using a simple circuit configuration with a single power supply, is proposed. To minimize undesirable crosstalk, the gate-source voltage of the JFET is driven to a negative value and retained in the state for a long period of time. (c) 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.