Research On The Characteristics And Applications Of GaN Power Devices

The dynamic and static performance of Si MOSFET is limited in further optimization because of the characteristics of silicon material and the packaging technology of the device,it makes the Si MOSFET difficult to meet the future needs of switching power supply with high efficiency and high power density.The performance of silicon power devices has been close to the limit,the development direction of the switching power supply is to be efficient highly with high power density.Therefore,a new type of device is needed for high frequency performance.GaN power devices are typical representatives of materials in wide bandgap semiconductors.Compared with silicon power devices,GaN power devices have lower on resistance,smaller switching losses,and smaller heat sink and simpler thermal management.GaN can provide lower gate charge,its switching speed is fast,and the parasitic parameters is small,and electrical parameters is superior.It is expected to replace silicon power semiconductor devices in the future.In recent years,a number of semiconductor manufacturers have introduced GaN power devices,but the current reference data is limited,so it is necessary to carry out further research work on GaN power devices.In this dissertation,the development and research status of GaN power devices at home and abroad are introduced,and their performance advantages and disadvantages are analyzed.In this dissertation,the main research object is the single-body enhanced GaN power device of GaN System,the static and dynamic characteristics of silicon power devices are compared and analyzed in detail.It is further verified that the high frequency switching characteristics of gallium nitride power devices are superior by building the simulation model of double pulse test and double pulse test circuit and test results analysis.According to the characteristics of switch type for monomer enhancement GaN power devices,this dissertation designed the output driver circuit with independent pull at high frequency,the ringing of GaN power devices caused by the parasitic parameters is analyzed.At the same time,the load experiment and optimization are carried out at high frequency.According to the simulation and experimental results of switching characteristics,the problem of parasitic parameters should be considered in the circuit simulation model of GaN power devices,and the method and strategy for the ringing phenomenon caused by parasitic parameters can be slowed down at turn-on and turn off time.In this dissertation,the BOOST converter is selected as the research topology of the application characteristics of the single-body enhanced GaN power device.According to the actual needs,the parameter design of BOOST converter based on GaN power device is carried out.And according to the high frequency switching characteristics of the GaN power device,the design of the control circuit,driving circuit and auxiliary power part suitable for high frequency work is designed.The feedback circuit is designed by the current mode work mode,and the operation requirements of adjustable input voltage and constant output voltage are realized.For the circuit design results of BOOST converter based on GaN power device,the application characteristics of GaN power devices are analyzed by simulation and experiment.The experimental results show that the high frequency switching performance of GaN power device is superior and the efficiency is remarkable,which can meet the demand of high efficiency and high power density of switching power supply.