Gallium nitride high-electron-mobility transistor (GaN HEMT) is a key enabling technology for obtaining high-efficient and compact power electronic systems. At the design stage of a power converter, the proper modelling of the GaN HEMT is essential to benefit from their good features and to account for the limits of the current technology. Circuit models of power MOSFETs have been deeply investigated by academia and industry for a long time. These models are able to emulate the datasheet information, and they are usually provided by device manufacturers as netlists that can be simulated in any kind of SPICE-like software. This paper firstly highlights the similarities and differences between MOSFETs and GaN HEMTs at the datasheet level. According to this analysis, the features of MOSFET circuit models that can be adopted for GaN HEMT modelling are discussed. This task has been accomplished by overviewing the literature on MOSFETs circuit models as well as analysing manufacturers netlists, thus highlighting the models MOSFETs valid or adaptable to GaN HEMTs. The study has revealed show that some models can be adapted for the GaN HEMT devices to emulate static characteristics at room temperature while the MOSFET models of dynamic characteristics can be used for GaN HEMT devices. This study enables the devices modellers to speed up the GaN HEMT modelling thanks to the use of some well-established MOSFET models. In this perspective, some suggestions to develop accurate GaN HEMT models are also provided.

GaN high electron mobility transistors (HEMTs) represent an emerging and key enabling technology for obtaining highly efficient and compact power electronic systems. The use of circuit models of power devices is essential for the optimal design of power converters, but while they have been deeply investigated for power MOSFETs and IGBTs, GaN HEMT models are still in their early stages. This paper first discusses the main similarities and differences between conventional MOSFETs and GaN HEMTs in terms of the datasheet information that the device manufacturers use to obtain the behavioral models that they usually provide as Spice-like netlists. Then, it highlights the strengths and weaknesses of using the behavioral models of MOSFET for GaN HEMT. To achieve this aim, a study of the existing GaN HEMT models revealed the lack of a proper modeling strategy for the dynamic conduction resistance, which is the most critical aspect of HEMT modeling. The difficulty is due to the dependence of the dynamic conduction resistance on quantities related to the application, which is a behavior absent in power MOSFETs. Consequently, future research efforts on GaN HEMT modeling must face this issue.