Inside the EPC91123: 6 kW 800 V–12.5 V GaN DC‑DC Converter for AI Servers

The EPC91123 is a 6 kW GaN-based DC‑DC converter reference design that delivers an isolated 800 V to 12.5 V conversion for AI servers and high‑performance computing. It uses an input‑series output‑parallel (ISOP) architecture with eight interleaved LLC modules, each processing about 750 W. Primary switches are 150 V EPC2305 GaN FETs, while secondary synchronous rectification uses 40 V EPC2366 devices, enabling operation around 1 MHz. This architecture reduces magnetics size, EMI, and thermal hotspots, achieving over 98% peak efficiency and more than 97% efficiency near full load at nearly 500 A output. Link: https://epc-co.com/epc/products/evalu...