Nonsegmented PSpice Circuit Model of GaN HEMT With Simulation Convergence Consideration

To solve the simulation convergence problem of enhancement mode gallium nitride high-electron mobility transistor (GaN HEMT) models, this paper proposes a nonsegmented model for GaN HEMT, which uses nonsegmented, smooth continuous equations to describe the static and dynamic characteristics of GaN HEMT. Furthermore, the static characteristic of GaN HEMT obtained by the nonsegmented model is verified by comparing the simulation curves with the static curves provided in datasheet; and the dynamic characteristic obtained by the nonsegmented model is verified by comparing the simulation result with the experimental result based on double pulse test platform. Moreover, to prove the good performance on simulation convergence of the proposed nonsegmented GaN HEMT model, the full-bridge dc-ac inverter with four GaN HEMTs has been employed as an example; the simulation result shows the good convergence of the inverter compared to the conventional segmented GaN HEMT model, which make it possible and flexible to research the power converters with GaN HEMTs by simulation way.

I. Introduction

Due to the limitations of silicon (Si) material properties, Si-based power electronics semiconductor devices have been gradually unable to meet today's high performance requirements for semiconductor devices in power electronics [1]. Based on this, gallium nitride (GaN) as the representative of the wide band gap semiconductor material came into being, compared to Si devices, GaN has higher bandwidth, breakdown voltage, and thermal conductivity, and these excellent features make GaN have significant advantage in high frequency and high power density applications [2]– [4]. As the most promising switching devices, there are already EPC, Transphorm, GaN systems, and other manufacturers to produce GaN high electron mobility transistor (HEMT). In order to predict the characteristics of GaN HEMT and optimize the power electronics circuits design with GaN HEMTs, an accurate GaN HEMT model is necessary [5], [6].