Active Gate Driver IC Integrating Gate Voltage Sensing Technique for SiC MOSFETs

The silicon carbide (SiC) MOSFETs provide superior properties over conventional silicon power devices with a higher switching speed and lower conduction losses. However, high-frequency switching can cause overshoots, oscillations, and electromagnetic interference (EMI) issues. Because of a fixed gate driving strength, the traditional gate driver struggles with the trade-off between overshoot and switching loss (switching speed). To improve the switching performance of the SiC power devices, an active gate driver (AGD) integrated circuit is proposed using a 0.18-μm CMOS HV BCD process is proposed in this article. Instead of requiring a separate programmable logic board, the controller circuits and driving stage are integrated on a chip. The proposed gate voltage sensing technique detects the slope difference of the gate voltage and generates the appropriate gate driving signals without detecting the SiC MOSFET ID and VDS information. The area and cost are reduced by removing the highvoltage sensing circuit for ID and VDS detection. The proposed AGD can also attenuate the oscillations of ID and VDS, further reduce the EMI noise induced by high switching speed. In addition, the experimental results show that the proposed AGD can be applied to different SiC power MOSFETs.