A 96.1% Peak Efficiency, 6.8 kW/in³, 48V-to-6V On-package Intermediate Bus Converter with LV-GaN Power Transistors

This paper presents the industry’s first and only 48V, on-package, intermediate bus converter (IBC) solution with an 8:1 fixed ratio using low-voltage (LV) GaN power transistors with 10x superior figure of merit over Si laterally diffused MOS (LDMOS) for high performance computing applications. Eleven 2x2 mm GaN half-bridge dies along with the passives are co-packaged to form an 8:1 switched capacitor divider. This 1-MHz 200-W IBC prototype achieves a peak efficiency of 96.1% and a power density of 6.8 kW/in<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>.