An Accurate Analytical Model for Wide Bandgap Devices Considering Dynamic Parasitic Parameters

Compared with traditional silicon devices, wide bandgap devices have better performance. For example, GaN HEMT exhibits superior switching speeds, lower on-resistance, and reduced switching losses compared to traditional silicon devices. However, parasitic parameters are highly sensitive to the high-speed switching process, which can lead to high-frequency oscillations. This article develops an analytical model based on a double-pulse test circuit. The model incorporates nonlinear capacitance, transconductance, and other factors. By utilizing datasheets and simulations, both static and dynamic parasitic parameters are extracted with high accuracy. The switching waveforms obtained from the analytical model are compared with LTspice simulations and experiment to verify the model's precision. This work provides theoretical guidance for improving GaN HEMT switching characteristics in practical applications.