GaN FET Model Validation Via Experimental Multiple Pulse Test

In power electronics design, validating the electronics switches' models is essential. The most recent transistor in wide-bandgap technology is the Gallium-Nitride FET (GaN FET). Several transistor models are developed to use the GaN FET in converter design. The more accurate device equivalent circuits are based on the Curtice and Angelov model. This paper deals with a model description and experimental validation of a normally-off GaN FET. In the paper, the validation is achieved by overlapping comparisons of the waveforms obtained from the model simulations implemented in LTSpice software with the experimental waveforms. Experimental boards with GaN FET in a half-bridge configuration have been used to test the device, considering fast and slow switching performance. Multiple pulse tests are experimentally conducted to measure the voltage and current waveforms of the GaN FET under test. Various current sensor solutions are explored and compared to sense the transistor current during the turn-on and turn-off transients, such as indirect measurement via a shunt resistor, a Rogowski coil, and a Hall effect current probe. The results obtained allow the converter designer to use the model to simulate complex power converter topologies with satisfactory certainty that the simulated GaN FETs represent an actual operating situation in static and switching conditions.