考虑寄生参数影响的碳化硅MOSFET开关暂态分析模型

Analytical Switching Transient Model for Silicon Carbide MOSFET under the Influence of Parasitic Parameters

为了评估回路及封装寄生参数对碳化硅MOSFET开关特性的影响,首先建立包括所有寄生参数的开关暂态等效电路模型,详细分析器件开通和关断整个开关暂态过程。然后,在考虑实际器件的负压偏置及器件寄生电容的非线性变化的基础上,推导碳化硅MOSFET所承受电气应力(电压过冲、电流过冲)的简化解析式。其次,基于开通和关断过程的小信号等效电路讨论振荡频率与寄生参数之间的关系。最后,通过对比实验和计算结果,验证了该分析模型的合理性,且能够反映出寄生参数碳化硅MOSFET开关特性的影响规律。

To assess the effects of loop and package parasitic parameters on silicon carbide MOSFET switching transient characterization,switching transient equivalent circuit model was firstly established under all the parasitic parameters,and the turn-on and turn-off transient process was analyzed in detail.Then,considering the negative bias voltage and the nonlinearity of device parasitic capacitance,simplified analytic expression of switching transient electric overstress was deduced.Furthermore,the relationship between oscillation frequency and parasitic parameters was also discussed,based on the small signal equivalent circuit.Eventually,the experimental and calculation results show that the analysis model is feasible and can reflect the influence of parasitic parameters on silicon carbide MOSFET switching characteristics.