Effectiveness of a SiC schottky diode for Super-Junction MOSFETs on continuous conduction mode PFC

This Super-Junction technology can dramatically reduce both on-resistance and parasitic capacitances, which usually have a trade-off relationship to each other. With smaller parasitic capacitances, Super-Junction MOSFETs have extremely fast switching characteristics and therefore reduce switching losses. But, naturally this switching behavior occurs with greater dv/dt and di/dt that affect switching performance via parasitic components in devices and the printed circuit board. Therefore, an optimized design is very important to operate high speed MOSFETs in practical applications. A SiC Schottky diode is an optimum device for fast switching MOSFETs for CCM PFC. It is well-known that the turn-on behavior of the MOSFET is strongly dominated by the reverse recovery characteristics of boost diodes on CCM PFC. Furthermore, SiC Schottky diodes are effective at dampening the down peak drain-source voltage and preventing gate ringing caused by lead inductance and parasitic capacitances of the boost switch. The objective of this paper is to determine which SiC Schottky diode is best-suited for fast switching MOSFETs.