Compact Model for Current Collapse in GaN-HEMT Power Switches

We present a simple yet accurate model describing current-voltage characteristics of GaN-HEMT power switches in presence of carrier trapping often referred to as current collapse. The model accounts for time-dependent changes in the source-gate and gate-drain resistances after application of high drain voltage. The model also has a regime describing ‘fast’ current voltage characteristics when the applied voltage swing occurs within a period of time much shorter than the characteristic trapping – detrapping times. The model is written in Verilog-A and can be implemented in SPICE-type circuit simulators.