High Temperature Isolated Gate Driver Technology For SiC MOSFET Power Modules

High temperature characteristics of Silinon Carbide(SiC)devices enable power electronic converters to operate at higher ambient temperatures,and the importance of high temperature isolated gate drivers is becoming increasingly significant.Compared with the complex Silicon on Insulator(SOI)high temperature gate driver chips and normal Si ICs with less high temperature resistance,the Si discrete devices based solution can well balance the temperature resistance and circuit cost.The SiC half-bridge power module is used to be driven,and a feasible high temperature isolated gate driver is designed by discrete MOSFETs,discrete transistors and oher passive components.Firstly,according to the selected module and possible working conditions,design the gate driver parameters and structure,and summarize the benefits and drawbacks of different structures.Then according to the voltage and current levels of electric signals,the gate driver is split into signal isolation and signal amplification.The idea of splitting also enables the proposed circuit design method to be flexibly applied to different applications.In signal isolation part,three different discrete devices isolation methods are analyzed and compared,and the method finally adopted is introduced in detail.In signal amplification part,the limitations of normal topologies are analyzed and improved to get better efficiency and high speed capability.In order to meet the high temperature requirements,discrete devices selection and consideration of power consumption of gate drivers will be throughout the design.The SiC module based double pulse test platform with 600 V maximum bus voltage is built,and a heating platform is used to heat the gate driver.Based on the full analysis of switching characteristics of SiC MOSFETs,the switching waveforms are evaluated and used to verify the high temperature isolation performance.Under continuous operating conditions,the main performance of the gate driver is analyzed in detail in the no load condition.Then 10 nF high temperature ceramic capacitors are used as the load to verify the high temperature driving capability,calculate and analyze the power consumption,and summarize the influences of temperature on the performance of the gate driver.Related work explored the feasibility and specific scheme of the gate driver in the development of high temperature power electronic converters in the future,this work belongs to the field of high temperature power electronics technology.