A large-signal Pspice modeling of GaN-based MIS-HEMTs

In this work we present a physics-based semi-empirical large-signal model for GaN MIS-HEMTs, which introduces the non-segmented, smooth continuous equations to describe the static and dynamic characteristics of GaN MIS-HEMTs in different working regions. The unique physical effect of threshold voltage drift was considered for MIS-HEMTs in the current model, in addition to effects of the channel length modulation and the temperature drift. In addition, a current controlled current source was used in the dynamic model to characterize the nonlinear capacitance including the gate-drain capacitance C-GD, gate-source capacitance C-Gs and drain-source capacitance C-Ds at different operating voltages. The model is in excellent agreement with the experimental data for both drain current and capacitances over a typical range of applied voltages and temperatures.