A Simple Approach to Improve the Switching Performance of Cascode GaNFETs

This paper analyses the switching performance of the cascode GaNFETs on Silicon substrates in three different PCBs using a double pulse test (DPT). A significant Vgs ringing is found during experiment. The source side parasitic inductance of cascade GaN with TO-247 package has been evaluated to cause significant gate voltage high frequency ringing. Moreover, reduction in Vgs high frequency ringing allows further reduction in input capacitance of the cascode structure. Which indicates a LV Si MOSFET with smaller input capacitance can be used in cascode GaNFETs. This enables faster switching transients and boosts the maximum switching frequency operation of cascode GaN devices, and thereby making use of the advantages that Gallium Nitride (GaN) brings. Method to reduce Vgs high frequency ringing is introduced in this paper. This enables stable switching transients and enhance the switching performance of cascode GaN devices, and thereby making use of the advantages that Gallium Nitride (GaN) brings. Simulation based on spice model is conducted for verification purpose.