Topology survey for GaN-based high voltage step-down single-input multi-output DC-DC converter systems

Abstract

In this work, several dc-dc converter topologies are examined for GaN-based, single-input, multi-output, large step-down applications; namely 200V∼400V dc distribution systems in modern defense, aeronautical, and datacenter industries. Many critical loads in these larger systems are supplied by 48V, 24V, 12V, or lower voltage sources, requiring a significant step-down of the main dc bus voltage. Due to these large conversion ratios, multi-stage schemes will be considered along with single-stage, multi-output converters. A discussion following analysis of each converter and an update on their current state-of-the-art will shed light on those converters that stand to benefit the most from GaN technology, along with a recommendation for a modular, GaN-based, power electronic building block for such DC-DC conversion applications with preference given to those topologies that lend themselves to modularity, high efficiency, and reduced size.