Wide Bandgap (WBG) power devices, and especially Gallium Nitride (GaN) High-Electron-Mobility Transistors (HEMTs) have recently demonstrated excellent performance in high-frequency, hard- and soft- switched topologies for various applications. This paper proposes a cost-effective and reliable "hybrid driving" approach to drive high voltage (HV) GaN HEMTs, achieving high performance while reducing implementation costs. The proposed circuitry comprises two single-channel gate driver ICs with very high common-mode transient immunity (CMTI), and a tunable bias supply circuit capable of negative bias voltage. Thus, the overall solution enables preventing parasitic Miller self-turn-on present in bootstrapped bias supplies, while enabling high dV/dt, shoot-through protection and versatile layout with a cost-competitive bill of materials (BOM). The feasibility of the hybrid driving approach is demonstrated through successful tests on a half-bridge power stage using gate-injection transistor (GIT) GaN HEMTs.
.jpg "Antonello Laneve (he/him/his) photo")