Physics-Based Analytical Model for High-Voltage Bidirectional GaN Transistors Using Lateral GaN Power HEMT

A bidirectional switching GaN transistor, PCB-packaged using commercially available high voltage power GaN HEMTs (200V, 3A) from EPC, has been modeled and characterized. A physics-based FET model, originally developed by Statz for short-channel GaAs MESFET, has been adapted to model both static and switching characteristics of both the constituent HEMT and the bidirectional switch up to 125 degrees C. We have found that the Statz model is superior to conventional short-channel MOSFET models due to the mixed pentode-triode on-state I-V characteristics of the EPC GaN HEMT. The bidirectional GaN transistor exhibits linear operation as well as bidirectional current saturation, offering low on-state resistance along with current limiting capabilities.