A New SPICE Model for the Electro-Thermal Behavior of GaN HEMT

High-precision GaN HEMT models play a crucial role in power electronics applications. Considering the limitations of silicon-based device models, which cannot be directly applied to GaN HEMTs, and the low accuracy of certain existing GaN HEMT models, a new electro-thermal model for GaN HEMTs is proposed in this paper. The model employs a logarithmic function for static modeling, providing a continuous characteristic that enhances flexibility in both positive and negative regions. Furthermore, the nonlinear expression of the drain-source capacitance C<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ds</inf> is improved, achieving higher fitting accuracy in the low-voltage range. Validation through static I-V and dynamic C-V characteristics demonstrates that the model achieves high accuracy, effectively fitting waveforms across the voltage range. Finally, a double-pulse test (DPT) circuit is implemented using LTSPICE software to simulate and verify the model’s switching characteristics. The results demonstrate that the model achieves excellent performance.