GaN HFET switching characteristics at 350V/20A and synchronous boost converter performance at 1MHz

Gallium Nitride HFET (Hetero-junction Field Effect Transistors) power switches are poised to replace silicon MOSFETs and IGBTs in many high-performance power switching applications. To realize the benefits of these fast-switching GaN devices, special circuit and packaging techniques are necessary. Drive circuits are significantly improved compared to conventional silicon MOSFET drivers. SMD packaging techniques are employed to minimize source inductance. The gate drive provides rise time of a few ns, and drain voltage slew rates of more than 80 V/ns are observed. These circuits are used for double-pulse switching performance characterization and in a synchronous boost converter operating under the same switching conditions. The GaN HFETs switch 350V and 20A in 15 ns with switching energy of 68 μJ. The 1MHz 300V synchronous switching boost converter is 94% efficient, with an output power of 1.2KW.