共栅共源结构GaN HEMT开关模型

Switching model of GaN HEMT in cascode configuration

为了计算共栅共源结构高压氮化镓(GaN)器件开关损耗,提出一种共栅共源结构GaN器件开关过程及损耗模型.通过考虑共栅共源结构中印制电路板(PCB)和引线寄生电感以及器件结电容,得出共栅共源结构GaN器件的等效电路模型,进而得到测试开关特性的双脉冲等效电路.按时间顺序将开通过程分为5个阶段,将关断过程分为4个阶段,对双脉冲等效电路进行分析和简化,并计算得出各个阶段中共栅共源结构GaN器件电压电流时域表达式,从而得到开关过程波形及损耗.在不同驱动电阻和开关电流下进行双脉冲实验,模型与实验的开关波形及损耗较吻合,表明所提出模型较准确.

A model to analyze the switching process and calculate the energy loss of cascode gallium nitride（GaN）transistor was presented in order to calculate the switching loss of high voltage GaN transistor in cascode configuration.The equivalent circuit model of the cascode GaN transistor was obtained through the analysis of the printed circuit board（PCB）and package parasitic inductances and the junction capacitors of the cascode GaN transistor,and then the equivalent double pulse circuit to test switching characteristics was obtained.The turn-on process was divided into five stages and the turn-off process was divided into four stages.The equivalent double pulse circuit of each stage was analyzed and simplified,and then the time domain expressions of voltage and current in each stage were illustrated.Moreover,the switching waveforms and energy losses were further obtained accordingly.The double pulse experiment was carried out at different values of current and gate resistor.The switching waveforms and energy losses of the proposed model fitted well with experimental results,which validated the accuracy of the proposed model.