Design And Implementation Of Dynamic Parameter Automatic Test Platform For SiC Power MOSFET

Because of excellent excellent thermal and electrical characteristics,SiC power MOSFETs are mostly used in fast power switching systems.In order to ensure the reliability of SiC power MOSFET in application,the study of its dynamic characteristics is very important.However,at present,research on the test platform for the dynamic characteristics of this type of device is relatively scarce.Therefore,designing an automated SiC power MOSFET test platform for dynamic parameter has high engineering application value.In this thesis,a driving circuit for SiC power MOSFET that can realize fast switching and negative voltage shutdown is designed.At the same time,the 1200 V withstand voltage busbar capacitor group is designed to meet the needs of high voltage and large instantaneous current during testing.Next,test circuits corresponding to the test principles of gate charge,switch,reverse recovery of body diode,short circuit,and avalanche tolerance are designed.In order to ensure that the test circuit is stable and reliable,through modeling and simulation,the influence of the parasitic inductance and parasitic capacitance at different positions of the circuit board on the switching characteristics of SiC devices are analyzed.Subsequently,the parasitic parameters in the test circuit are extracted.According to the analysis results,the parasitic parameters are optimized by perfecting the layout of the test circuit board,and finally the hardware design of the test circuit is completed.In addition,in order to improve test efficiency,a set of programs for Keythley2410,AFG3102 C and MDO3024 used in the testing process that can realize one-key testing is designed using Labview software.Subsequently,the software part and the hardware platform were combined,and the design of the test platform was completed.Finally,the test system is verified.The verification results show that the test platform designed in this paper can achieve automatic testing of dynamic parameters of SiC power MOSFET such as gate charge,switching,body diode reverse recovery,short circuit and avalanche tolerance,The maximum test error is the switch rise time Tr,the error is 9.2%,the minimum test error is the switch fall time Tf,the error is 1.2%,which meets the design specifications(the maximum error is less than 10%).