Optically Switched-Drive-Based Unified Independent dv/dt and di/dt Control for Turn-Off Transition of Power MOSFETs

To control the switching dynamics of an optically triggered hybrid device, a photonic-control mechanism is outlined. The optically triggered hybrid device comprises a power MOSFET, as the main power semiconductor device (PSD), and a pair of GaAs-based optically triggered power transistors (OTPTs), serving as the driver for the power MOSFET . The switching-transition controller modulates the turn-off transition of the power MOSFET by modulating the optical intensity of the OTPTs. The independent and unified $dv/dt$ and $di/dt$ control of the PSD is achieved using a single control circuit which also predicts the onset of transition between the $di/dt$ and the $dv/dt$ regions of control. Experimental control results validating the OTPT-based dynamical modulation of the turn-off characteristic of the power MOSFET are provided. In this study, the power MOSFET is chosen to be a SiC mosfet . However, the proposed photonic-control mechanism can be extended to Si power MOSFETS as well.