An Improved Gate-Boosting Gate Driver for Ultrafast Switching of GaN Transistors for Nanosecond Pulse Generation

Gallium nitride high-electron mobility transistors (GaN HEMTs) offer ultrafast switching capabilities because of their compact physical structure, resulting in smaller parasitic components and a lower gate charge requirement. This fast switching capability enables the utilization of the GaN transistors in pulsed power generators such as solid-state impedance-matched Marx generator (IMG). In such applications, the faster rise time of the generated high-voltage and high-current pulses enhances the efficiency of plasma generation in the plasma reactor. Additionally, achieving higher switching speeds is possible by utilizing an enhanced gate driver featuring a high driving current capacity and fast rise/fall times; therefore, numerous research studies have explored various gate-driving methodologies and their implementation. In this article, an improved gate-boosting driving method, originally proposed for IGBTs and then optimized for SiC MOSFETs, is proposed and implemented for driving 650-V GaN transistors to reduce their turn-on time as effectively as feasible. In the proposed improved gate driver, the switching performance of the main 650-V GaN transistor has been evaluated in both simulation and experiments under pulse operation with a resistive load of up to 610and107 A. The obtained rise-time results for the proposed gate driver in simulation and experiments are 1.53and1.71 ns, respectively. Furthermore, current rise rates of 69.94<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\scriptstyle \text {}^{\scriptstyle \mathrm {~ {\mathrm {\text {k}\text {A} }}}}}\hspace {-0.224em}/\hspace {-0.112em}{\scriptstyle \mathrm {~ {\mathrm {\mu \text {s} }}}}$</tex-math> </inline-formula> and 62.58<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\scriptstyle \text {}^{\scriptstyle \mathrm {~ {\mathrm {\text {k}\text {A} }}}}}\hspace {-0.224em}/\hspace {-0.112em}{\scriptstyle \mathrm {~ {\mathrm {\mu \text {s} }}}}$</tex-math> </inline-formula> are achieved in simulation and experiments. The achieved rise time and current rise rate results demonstrate the applicability of the proposed gate-driving technique to be used in the upcoming iterations of the IMG to generate nanosecond pulses and, as a result, a more efficient plasma yield.