SiC结型场效应功率晶体管特性及其驱动设计

Research on Characteristics and Driver Circuit of SiC JFET

SiC结型场效应功率晶体管(JFET)是目前较成熟的宽禁带功率半导体,具有良好的电气性能。但在使用过程中,JFET存在常态下开通的特性与开关时du/dt对驱动电压影响较大的问题。在分析器件等效电路的基础上,从理论上讨论了du/dt对驱动电压的影响,并提出一种驱动电路。该驱动电路采用电平转化电路及有源吸收电路,实现了控制电路信号与SiC器件驱动信号逻辑电平匹配;同时,在高速开关时,能有效减小容性电流对驱动电压的影响,可靠开关SiC器件。最后,给出了驱动信号、驱动电压变化及器件开关过程的实验波形,证明了驱动电路的有效性。

SiC junction field effect power transistor（JFET） is a much mature wide band gap power semi-conductor at present.It has good electrical properties.Whih in usage,the device has normally on problem,and the drive voltage drop caused by du/dt is much serious.Based on the discussing analysis of the device＇s equivalent circuit and the theoretically analysing on impact of duldt to the drive voltage, this paper presents a drive circuit.By taking level con- version circuit and the active snubber circuit, it realizes logie level matching of the control signals and the SiC device drive signals.when operating at high speed switching, it can effectively reduce the influence of the capacitive current to the drive voltage,and reliably switch the SiC device.Finally,the experimental waveforms of drive signals,the drive voltage and device switching are shown to prove the validity of the driver circuit.