Fractional-Order Equivalent Model for Dynamic On-Resistance of GaN HEMTs

GaN high electron mobility transistors (HEMTs) have been widely used due to their high withstand voltage characteristic and low parasitic parameters. However, these devices always face power losses caused by electron trapping effects, which perform in the form of the on-resistance of the devices. In this work, a fractional-order equivalent model is proposed for characterizing the dynamic on-resistance of GaN HEMTs, in which a fractional-order capacitor is introduced to describe the long-tailed distribution of time constants of electron detrapping effects. A cuckoo search algorithm-based parameter identification scheme is developed for extracting the parameters of the proposed model. The comparison between the prediction of the proposed model and experiments shows that, the dynamic on-resistance of GaN HEMTs can be characterized concisely and effectively.