桥式电路中SiC MOSFET串扰峰值预测算法研究

Research on Crosstalk Peaks Prediction Algorithm of SiC MOSFET in Bridge Circuit

文中针对串扰电压峰值与驱动回路阻抗间的非线性关系,分段分析共源电感存在时串扰产生机理,提出一种碳化硅(silicon carbide,SiC)金属氧化物半导体场效应管(metal-oxide-semiconductor field-effect transistor,MOSFET)串扰电压的分析模型及预测算法。所提算法综合考虑共源电感、非线性极间电容等寄生参数与探头接线的影响,可实现引脚测量串扰电压的准确计算及器件内部串扰电压的提取。进一步,该算法针对栅极回路建模,并利用实测数据引入漏源电压与源极电流时变性,可适用于多桥臂电路及不同器件工况。最后,实验结果表明,所提算法可精准预测不同关断态驱动阻抗下的串扰峰值,其正向峰值平均预测误差仅为3.2%。该算法可为SiC MOSFET驱动电路设计提供定量计算参考。

Aiming at the nonlinear relationship between the peak value of crosstalk voltage and the impedance of gate loop,this paper analyzes the mechanism of crosstalk voltage in the presence of common-source inductance.An analytical model and a prediction algorithm for crosstalk voltage of silicon carbide metal-oxide-semiconductor field-effect transistor(SiC MOSFET)are proposed.The proposed algorithm comprehensively considers parasitic parameters such as common-source inductance,nonlinear inter-electrode capacitance and the influence of probe wiring,which can realize the accurate calculation of pin measured crosstalk voltage and the extraction of device internal crosstalk voltage.Furthermore,the proposed algorithm only models the gate loop,and uses the measured data to introduce the time-varying of drain-source voltage and source current,which can be applied to multi-arm circuits and different device operating conditions.Finally,the experimental results show that the proposed algorithm can accurately predict the crosstalk peaks with different OFF-state gate impedance,and the average prediction error of positive peaks is only 3.2%.The proposed algorithm can serve as a quantitative calculation reference for the design of SiC MOSFET drive circuit.