An Integrated Suppression Method of both GateSource Voltage Oscillation and Crosstalk for GaN HEMT Gate Driver

There are serious gate-source oscillation and crosstalk problems in the application of gallium nitride (GaN) devices characterized by faster switching speed and lower threshold, which causes mis-conduction and breakdown of the gate. A gate diver integrated suppression of gate-source oscillation and crosstalk for GaN HEMT (ISGD)is proposed in this paper as the solution for these problems. An additional capacitor in the proposed gate diver can be used to absorb gate-source voltage spike without affecting the switching speed by its pre-charging and be a part of the charge pump at the same time, which can generate negative voltage to leave margin for the influence of positive crosstalk and build a low impedance path to suppress negative crosstalk without an additional negative supply. By decoupling the precise generation timing of self-recovering negative voltage from the switching process, it becomes feasible to the implementation of negative voltage to almost avoid dead time, thereby further reducing reverse conduction loss during dead time. Furthermore, the integrated suppression of gatesource voltage oscillation and crosstalk can simplify the circuit, enhancing reliability for engineering applications. A double-pulse test (DPT) based on the GS66508B verifies the effectiveness of ISGD as a solution for the gate-source voltage oscillation and crosstalk.