Active Gate Driving of Cascoded SiC JFETs

In this paper, the gate driving characteristics of a SiC cascoded Junction Field Effect Transistor (JFET) is explored. Firstly, a Conventional Gate Drive (CGD) circuit is analyzed and implemented, followed by the proposal and implementation of two Active Gate Driving (AGD) methods for the cascoded JFET. Two approaches of gate control are explored: i) using the low-voltage -MOSFET gate & (ii) using the JFET gate. Switching characteristics during turn-on and turn-off for the CGD and both AGD approaches are compared, and it is observed that the proposed AGD circuits provide controllability of both switching edges and thus allowing an application optimized switching operation. Analytical, simulation and experimental results are shown to verify the proposed methods.