Failure Analysis Of Power MOSFET And Design Of Drive Circuit

As many countries around the world have issued tougher environmental treaties,the new energy products have been widely used, people pay more attention on powerconverter. The advantage of MOSFET is that it allowing the converter to achieve asmaller volume and a higher efficiency. The parallel technology of MOSFET canincrease its voltage and current capacity, broaden its application. The main purpose ofthis dissertation is make the power MOSFET work safely and reliably, analyzed thefailure mode, designed the parallel driver circuit. The main contents are as follows:Expounded the structure and basic principle of the power MOSFET, andanalyzed the operating characteristics of the power MOSFET on the basis of these.Emulation analysis is carried out with the characteristics of current sharing, selectedthe model of the power devices.The dissertation classified explained the main parameters of the power MOSFET,analyzed the causes of three main failure modes of the power MOSFET, gave thecorresponding solutions and methods, improved the work stability of the powerMOSFET.Studied the miller effect during the of the switching time of power MOSFET,given method to suppress the Miller effect, and then calculated the main parametersof the drive circuit, selected the appropriate driver chip, designed a practical paralleldriver circuit of power MOSFET.Different modes of operation for the converter experiment to test the PWMsignals, and the waveforms of main parameters of the power MOSFET using diferentdrive resistance. By analyzing the experimental results to verify the synchronizationof the PWM signals, realized stability work of power MOSFET in parallel.