Temperature Effects of GaN HEMTs on the Design of Power Converters

This paper proposes an experimental study of temperature effects on Gallium Nitride (GaN) High Electron Mobility Transistors (HEMTs). The output and transfer characteristics are monitored at temperatures ranging from 5°C to 105°C. The temperature dependency on static parameters of GaN HEMT is examined, such as: drain current (IDS), on-state resistance (RDS(ON)), transconductance (gm), threshold voltage (VTH) and the gate leakage current (IGSS). The decreases of IDS and gm accompanied with the increase of RDS(ON) and IGSS when increasing temperature have been observed. Moreover, the decrease in electron mobility with increasing temperatures is considered to be one of the causes of the reduction in the drain current and transconductance. In order to study the impact of temperature on power converters with GaN HEMTs by simulation approach, the thermal characteristics of a 650V, 30A GaN HEMT have been modelled. The used model is a nonsegmented Electro-thermal SPICE model of Motorola. The model parameters are extracted using Levenberg-Marquardt Algorithm.