基于恒流源的增强型GaN动态导通电阻特性研究

Research on dynamic on-resistance characteristics of E-Mode GaN device based on constant current source

动态导通电阻现象会导致GaN器件导通电阻增加,不仅会增大器件通态损耗,还会使器件温升更加显著,是限制GaN器件在高频度变换器中应用的重要因素之一。针对该现象,设计一种基于高速脉冲恒流源的动态导通电阻测试平台,并利用该平台分析了两款不同电压等级器件的导通电阻对断态电压应力、断态电压持续时间以及环境温度的影响。研究结果表明:当断态电压应力增大到两款器件各自额定电压的60%,两款器件的导通电阻分别较各自的标称值变化了15%和25%;断态电压持续时间增至100 s,两款器件的导通电阻分别较各自标称值变化了40%和81%;随着环境温度增大到125℃,两款器件的导通电阻分别较各自的标称值变化了102%和105%。GaN器件动态导通电阻现象较为显著,因此有必要在设计变换器时慎重地考虑GaN器件的工况,以保证在符合系统指标的前提下降低动态导通电阻的影响,从而提高GaN器件的效率。

The phenomenon of dynamic on-resistance can lead to an increase in the on-resistance of GaN devices,which not only increases the on-state loss of the device,but also makes the temperature rise of the device more significant,which is one of the important factors limiting the application of GaN devices in high-frequency converters.To address this phenomenon,a dynamic on-resistance testing platform based on high-speed pulse constant current source is designed,and the effect of the on-resistance of two different voltage level devices on the off state voltage stress,off state voltage duration,and ambient temperature is analyzed by means of this platform.The research results show that when the off state voltage stress increases to 60%of the rated voltage of the two devices,the on-resistance of the two devices can change by 15%and 25%respectively compared with their respective nominal values;The duration of the off state voltage can increase to 100 s,and the on-resistance of the two devices can change by 40%and 81%respectively,from their respective nominal values.As the ambient temperature increases to 125℃,the on-resistance of the two devices can change by 102%and 105%respectively,from their nominal values.The dynamic on-resistance phenomenon of GaN devices is obvious,so it is necessary to carefully consider the working condition of GaN devices when designing converters to ensure that the impact of dynamic conduction resistance is reduced while meeting system indicators,thereby improving the efficiency of GaN devices.