High-Power Density, 900-W LLC Converters for Servers Using GaN FETs: Toward Greater Efficiency and Power Density in 48 V to 6/12 V Converters

摘要

The LLC resonant converter can achieve soft switching over a wide operating range, making it a suitable candidate for high-efficiency dc-dc conversion, even at a high output current. We applied enhancement-mode gallium nitride (eGaN) fieldeffect transistor (FET) technology to a 1-MHz, 900-W LLC resonant converter in a fixed 4:1-ratio dc-dc transformer application operating with a 48-12-V conversion suitable for data-center applications. The converter achieves power efficiency and density density exceeding 98% and 1,500 W/in