It is common knowledge that there is a non-recurring inrush current present at the SMPS initial turn on. Therefore, designers will need to take caution to protect main power devices during a cold start turn-on. In PFC applications using silicon devices, the silicon boost diode is usually selected with a much higher current rating compared to real application average output power, which inherently provides sufficient surge current protection. However, with SiC Schottky diode, since the device selection is sized to appropriate forward current rating, the die is relatively smaller. Thus, extra-caution needs to be given to the surge current protection. Often the surge current rather than forward current rating will dictate the choice of SiC diode size.