A Physics-Based Empirical Model of Dynamic IOFF Under Switching Operation in p-GaN Gate Power HEMTs

In this article, an empirical model of dynamic OFF-state leakage current (I-OFF) under switching operation in p-GaN gate high-electron-mobility transistors is established based on its underlying physical mechanism. The impacts of relevant switching conditions, including switching frequency, duty cycle, OFF-state delay time, gate drive voltage, and temperature are all considered in the modeling of dynamic I-OFF. A good agreement between the modeled dynamic I-OFF and experimental results is achieved. Based on this model, the OFF-state power consumption (E-OFF) and OFF/ON-state power consumption ratio (E-OFF/E-ON) under dynamic switching operation can be predicted for various switching conditions. As the device worked at a high switching frequency (e.g., 1 MHz and duty cycle: 50%) with a gate drive voltage of 7 V and temperatures from 25 to 150 degrees C, the E-OFF/E-ON ratio is calculated from 0.53% to 0.07%, which is three to two orders of magnitude higher than what is projected from static OFF-state current characteristics.