Evaluation of GaN HEMT dv/dt Immunity and dv/dt Induced False Turn-On Energy Loss

With the high switching speeds of GaN HEMTs, there is an increased risk of dv
DS
/dt induced shoot-through events in bridge configurations. In cases where shoot-through is present, an accurate method to quantify the false turn-ON energy loss is essential to understand the severity of it and GaN HEMT dv
DS
/dt immunity. The capturing and evaluation of a shoot-through event is challenging due to the limited accuracy in instantaneous electrical measurements, and the inaccessibility of the gate node at die level. To address this, first, we revisit the concepts of dv
DS
/dt immunity and its relation to device gate–source and gate–drain parasitic capacitances. We show that the maximum value of the induced v
GS
spike occurs at a dv
DS
/dt value much lower than the peak dv
DS
/dt value, providing important insights. Then, we propose a simple and robust experimental approach, adapting a no-load circuit, to quantify dv
DS
/dt induced shoot-through energy loss. The technique does not require any high-frequency voltage or current measurements on the device, and it solely relies on average current and voltage measurements external to the device. It is also experimentally demonstrated that e-GaN HEMTs with a monolithically-integrated Miller clamp offer significant shoot-through immunity as opposed to conventional solutions.