Optically-Controlled 3.3 kV SiC MOSFET with Fast Switching Speed and Low Optical Power

Optically-controlled high-voltage power devices hold good promise for grid and renewable energy applications by providing superior electromagnetic interference (EMI) immunity and reduced switching delay. This paper proposed a novel optically-controlled gate driver architecture that applies complementary optical signals to two photodiodes (PDs) arranged in a totem-pole configuration. This configuration enables fast switching of power semiconductor devices using minimal optical power, as only low-power driver signals are optically modulated and device main current is not photogenerated. To validate this approach, we employ two InGaAs PDs to drive a 3.3 kV SiC MOSFET, the highest-voltage industrial unipolar device currently available. When each PD is illuminated by 21.7 mW optical power, the SiC MOSFET achieves hard-switching at 1500V/3A, with rise and fall times of 152 ns and 214 ns, respectively. These results set new records for switching voltage, speed, and power capacity-to-optical power ratio in optically-controlled unipolar power switches. This general optical driver design is also applicable to the future development of integrated optics for power electronics in diverse (ultra-) wide-bandgap semiconductors.¹