Research On Drive And Protect Circuit Of Silicon-carbide MOSFET

As a new generation of wide band gap semiconductor devices,silicon carbide Si C MOSFET has attracted much attention due to its excellent characteristics in high voltage and high-power applications.The use of silicon carbide(Si C)MOSFET can significantly mention the power density and efficiency in power devices such as charging pile inverters.This paper focuses on drive and protection circuits of Si C MOSFET.First of all,the device structure and working principle of Si C MOSFET are introduced.The turn-on and turn-off process of Si C MOSFET are analyzed in detail by the equivalent circuit of the diode clamped inductive load.Then,the parameters affecting the on-off performance of Si C MOSFET are analyzed and studied.And,the parameters of gate parasitic inductance,source parasitic inductance,drain parasitic inductance,gate-source parasitic capacitance and gate-drain parasitic capacitance,which affect switching characteristics,are analyzed and studied in detail by simulation circuit.Secondly,the requirements of Si C MOSFET driving part are analyzed in detail.The calculation methods of driving power,driving peak current,driving voltage amplitude and other parameters are given.In order to avoid the influence of interference signals,the driver also has the function of driving signal preprocessing.This function effectively filters out short pulse signals(glitches)during driving and reduces the risk of Si C MOSFET damage due to erroneous driving signals.The difference between traditional si power MOSFET driving circuit and IGBT driving circuit and Si C MOSFET driving circuit are analyzed.The gate-source voltage drop phenomenon of Si C MOSFET during switching on is analyzed.And,a special driving circuit using auxiliary current source is designed according to the switching characteristics of Si C MOSFET.Thirdly,the characteristics and causes of over-current fault of Si C MOSFET are analyzed in detail.VDS desaturation detection and shunt detection are combined to protect the over-current fault.At the same time,the gate-source overvoltage and gate-drain overvoltage protection circuit is designed.Finally,a dual pulse test platform is built to verify the double pulse experiments of CAS300M12BM2 and C2M0160120 D Si C MOSFET.Then the short-circuit experiment of Si C MOSFET is verified by C2M0160120 D.