Modelling and quantification of power losses due to dynamic on-state resistance of GaN E-mode HEMT

This paper investigates a method for quantifying the additional losses in high-voltage GaN enhancement mode HEMTs (eHEMT) employed in converter applications. The additional losses stem from the phenomenon known as current collapse or dynamic on-state resistance. The goal of this work is to investigate how these losses contribute to the total power loss in converter application. Measurement and modelling methods in the literature are reviewed. Changes to the measurement circuit are made to improve measurement accuracy. Measurements of dynamic on-state resistance are made on a commercial GaN eHEMT. The experimental results shows that the resistance depends on both dc-link voltage and blocking time. The resistance waveform and initial attempts at modelling the dynamic on-state resistance indicate that the suggested model is suitable for modelling the losses in LTSPICE software.