Negative Voltage Driver Research And Design Of A GaN Power Device

Power integrated circuit,because of its high integration,low power consumption,which is widely used in the power electronic application systems.The depletion mode gallium nitride(GaN)power devices gradually replacing traditional power devices because of its higher switching speed and higher breakdown voltage meet the demand of high frequency and high reliability for electronic systems.But traditional power driver have high delay time and output negative voltage can not match depletion mode GaN power devices,so the traditional power driver can not be used to drive depletion GaN power devices.Under this background,the design of integrated negative voltage driver for depletion mode GaN power devices become a significant study.Firstly,this thesis introduces the characteristics of depletion mode GaN power devices,and the require of gate driver design for depletion mode GaN power devices.Then analyzed the delay time of negative voltage level shifter and the principle of negative voltage generator.This thesis mainly study negative voltage driver need two power supplys,output negative voltage can not match the gate driver of depletion mode GaN power devices and the negative voltage level shifter.Finally,an new integrated negative voltage driver for GaN power device is designed.The proposed driver with negative voltage can be divided into two parts mainly:the first is negative voltage generator,which is realized by charge pump circuit and need only one power supply;the second is low delay time negative voltage level shifter,which realized by the method of signal parallel transmission to reduce the delay time.The proposed integrated negative voltage driver for depletion mock GaN power devices has been implemented in 02.5pm BCD technology.Compared to conventional driver with negative voltage technique,the test results show that the proposed need single 12V power supply only,the range of the output voltage is-7V-0V,output drive current is 49.9mA.What's more,the delay time of the driver is about 5.3ns.So the goals of the design are achieved.