一种改进型抑制SiC MOSFET桥臂串扰的门极驱动设计

由于传统驱动中SiC MOSFET在高开关频率的情况下其寄生参数造成的桥臂串扰更加严重，而现有的抑制串扰驱动电路大多是以增加开关损耗，增长开关延时和增加控制复杂度为代价抑制串扰。因此，根据降低串扰产生过程中驱动回路阻抗的思想，提出一种在栅源极间增加PNP三极管串联二极管和电容的新型有源密勒钳位门极驱动设计，并分析其工作原理，对改进驱动电路并联电容参数进行计算设计。最后，搭建了直流母线电压为300V的同步Buck变换器双脉冲测试实验平台，分别与传统串扰抑制电路，典型串扰抑制电路的正负向串扰电压尖峰抑制效果和开通关断速度做对比分析。实验结果表明，提出的串扰抑制驱动电路正负向电压尖峰分别比传统和典型串扰抑制电路降低了80%和40%，同时减少了32%的器件开关延时。

An Improved Gate Drive Design to Suppress Crosstalk of SiC MOSFET Bridge Circuit

Because the parasitic parameters of the SiC MOSFET in the traditional drive are more serious in the case of high switching frequency, the bridge arm crosstalk caused by its parasitic parameters is more serious, and most of the existing crosstalk suppression drive circuits suppress crosstalk at the expense of increasing switching loss, increasing switching delay and increasing control complexity. Therefore, based on the idea of reducing the impedance of the drive loop in the process of crosstalk generation, a new type of active Miller clamp gate drive design with a PNP transistor series diode and capacitor added between the gate and source is proposed, and its working principle is analyzed to improve The parallel capacitance parameters of the drive circuit are calculated. Finally, a double-pulse test experimental platform for a synchronous Buck converter with a DC voltage of 300V was built to compare and analyze the positive and negative crosstalk voltage spike suppression effects and turn-on and turn-off speeds of traditional crosstalk suppression circuits and typical crosstalk suppression circuits. The experimental results show that the positive and negative voltage spikes of the proposed crosstalk suppression drive circuit are reduced by 80% and 40% respectively compared with the traditional and typical crosstalk suppression circuits, and the switching delay of the device is reduced by 32%.