Design Of Single-switch Resonant Converter Circuits And Systems Using Integrated GaN Power Transistor

With the widespread application of the high-speed power semiconductor gallium nitride（GaN）in power electronics,it’s increasingly important of the research on high frequency power supply module,aiming for fully exploiting the potential of GaN de-vices.Compared with the traditional hard switching type circuits,resonant type DC-DC converters could maintain high conversion efficiency at higher frequency thanks to its soft switching operation.Single switch resonant converters（Single Switch Resonant DC-DC Converter,SSRC）have become a research hotspot because of simple driver structure and control approach.However,SSRC shows low efficiency at light load op-eration due to its soft switching property is sensitive to the load modulation.In addition,the design process based on PCB also limits the increase in the power density of the converter,which limits its application in portable electronic devices.To solve the problem of soft switching in SSRC circuits being affected by load change,current harmonics analysis method is proposed.Small amount of 2^nd harmonic current component is injected through impedance matching between the inverter and rectifier circuits,which guides the realization of zero-voltage-switching（Zero Voltage Switching,ZVS）in full load range.Direct process for calculating the parameter value of the resonant elements is given.In order to verify the proposed design method,a prototype with a switching frequency of 20MHz based on enhanced GaN devices is designed.Simulation and test results show that the output power of the circuit is 2W and the efficiency is up to 92%.The converter maintains ZVS over quite wide load range that 5 times wider than exist references.Aiming at the problems of the difficulty of integrating high-frequency resonant components and the serious parasitic effects of the circuit board,a three-dimensional hybrid integrated SSRC circuit topology is proposed.A 500MHz frequency SSRC cir-cuit is designed based on the silicon-based 0.13μm SOI process and GaN devices.The planar spiral inductors and power device parasitic capacitors are used as resonant com-ponents.The entire layout is only 9mm²,and the power density could reach1481m W/mm².From the simulating results,the efficiency at full load is 60%,and the highest efficiency is 89%.This design realizes the on-chip integration of SSRC circuit for the first time,and the power density is higher than the existing integrated GaN on-chip converters from references where the efficiency is compactable.