Investigation on the Activation Energy of Device Degradation and Switching Time in AlGaN/GaN HEMTs for High-Frequency Application

In this paper, the influence of traps on the dynamic on-resistance (R-d(son)) and switching time of AlGaN/GaN high-electron-mobility transistors is validated by means of a switching power converter with floating buck-boost topology. A new scheme based on the voltage-dependent dynamic R-d(son) is proposed to extract the average activation energy of device degradation. The average activation energy obtained is 2.25 eV at 50-200 V and 2.60 eV at 200-600 V. In addition, the dynamic R-d(son) is accurately extracted by a unique extraction circuit with high switching frequency up to 1 MHz and high off-state voltage up to 600 V. Meanwhile, the switching times at turn-on and turn-off transitions are captured in a floating buck-boost converter, showing that the transconductance decreases with increasing drain voltage. Furthermore, the effect of parasitic output capacitor on the dynamic R-d(son) is investigated by an experimental method. Finally, a proper hard operating mode is proposed to alleviate the influence of the trapping effect on the performance of switching power converters.