Dynamic ON-State Resistance Test and Evaluation of GaN Power Devices Under Hard- and Soft-Switching Conditions by Double and Multiple Pulses

The dynamic ON-state resistance (R-DSON) behavior of commercial GaN devices is very important for a GaN-based converter. Since the zero-voltage switching techniques are popular in high-frequency power conversion, a dynamic R-DSON test board integrating both hard- and soft-switching test circuits is built in this study. Two types of commercial GaN devices are tested and compared under hard- and soft-switching conditions by double-pulse and multipulse test modes, respectively. It has been found that their dynamic R-DSON exhibit different behaviors depending on the OFF-state voltage and frequency under hard- and soft-switching conditions due to different device technologies, which should be taken fully into account for GaN-based converter design and loss estimation. In order to simulate the R-DSON behavior in a steady-state operating converter, a multipulse measurement has been implemented, the results of which are compared with that of double-pulse test. Furthermore, the primary trapping mechanisms responsible for dynamic R-DSON increase under different switching conditions are identified and verified by the numerical device simulation using Silvaco TCAD tool.