Measurement Of GaN Power Devices And Application On Power Switching

With the mobile electronic devices such as mobile phones and tablet computers popularized rapidly,the market is increasingly demanding high-efficiency and high-power fast charging adapters.Due to the large size and overheating,which are caused by the low switching frequency of the device and the low power conversion efficiency,power adapters based on traditional silicon semiconductor power devices have become increasingly difficult to meet the application of fast charging adapters with small-size and high-power.In recent years,Ga N power devices have become a popular choice for small-sized and high-power fast charging adapters due to their excellent characteristics such as high switching frequency,low on-resistance,and high breakdown voltage.Under this background,this paper focuses on the analysis of the characteristics of Ga N power devices and the oscillation suppression and efficiency improvement in switching power supply applications.The main research work and results are as follows:First,the design of the drive circuit of the Ga N power device was studied,and the model of the drive slow-down oscillation circuit was established.Through the optimization of the circuit structure design,the waveform oscillation,voltage overshoot,and parasitic effects in the dynamic characteristics of the Ga N power device were realized.,Miller effect and other problems.A double-pulse test circuit for Ga N power devices was built.By selecting a driving voltage of 0V to +6V at high frequency,it can effectively prevent voltage overshoot.The influence of the change of driving loop voltage and current on the performance under the Miller effect is studied,and measures such as strong gate pull-down,small inductance,and negative gate bias of-2V to-3V are proposed to reduce the Miller effect.Designed the LM5114 drive circuit with independent input and output and built a 50 k Hz and 500 k Hz gallium nitride power device double pulse test circuit.The experiment shows that the designed drive circuit can effectively reflect the waveform stability and high switching of the gallium nitride power device at high frequency.Speed working characteristics.Next,the oscillation mitigation of the Ga N power device drive circuit was studied.Firstly,the driving performance of the Ga N power device is optimized,and the polygonal and symmetrical layout design is given according to the parasitic inductance of the line;secondly,the simulation shows that adding 1? gate resistance can effectively reduce the driving oscillation;then for the oscillation problem,the RCD absorption is separately The circuit,magnetic bead mitigation method and new integrated drive mitigation method are analyzed in detail and verified by simulation to verify their effectiveness.Finally,the oscillation mitigation and efficiency improvement issues in Ga N power supply applications are studied,and a high-efficiency Ga N BOOST circuit design is implemented.Through the simulation analysis of the Ga N power device BOOST drive circuit,the 50% duty cycle and 100 k Hz switching frequency Ga N-based BOOST drive circuit was designed and completed,which effectively slowed down the waveform oscillation;built an on-board power converter based on the above design and development Circuit optimization design,the efficiency reaches 91.86%,significantly improved than before optimization.