TIDT275 April 2022
This reference design is a GaN-based 3-kW, phase-shifted full bridge (PSFB) targeting high-power density of 279 W/in3. The design employs an active clamp to minimize voltage stress on the secondary synchronous rectifier MOSFETs, enabling use of lower voltage rating MOSFETs with better figure-of-merit (FoM). PMP23126 uses 30-mΩ TI GaN on the primary side and silicon MOSFETs on the secondary side. The LMG3522 top side cooled GaN device with integrated driver and protection enables higher efficiency by maintaining ZVS over a wider range of operation compared to Si MOSFET. The PSFB operates at 100 kHz and achieves 80 plus Titanium when paired with the PMP23069.