A 48V to 3V-5V Hybrid Converter with Inductor at Low-Q Stage Achieving 93.4% Peak Efficiency and 723W/in<sup>3</sup> Power Density for AI Servers
This paper presents a hybrid buck converter with inductor at low-charge stage designed to convert 48V to 3V-5V for powering AI servers. This converter is based on a Fibonacci switched-capacitor topology with an optimized wiring method for fully utilizing flying capacitors to realize a large voltage conversion ratio. Moreover, with an inductor placed at the low-charge stage, inductor current is further reduced, and hence inductor DCR loss is significantly reduced for enhanced efficiency, and the reliance on a bulky inductor is mitigated for better power density. A hardware prototype was implemented with discrete MOSFETs and drivers to validate the proposed converter, providing a maximum output current of 30A. Measurement results show that the converter achieves a peak efficiency of 93.4% and a power density of up to 723W/in<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup>.
Authors
- Yichao Ji (ORCID: https://orcid.org/0009-0008-1415-1412)
- Lin Cheng (ORCID: https://orcid.org/0000-0002-3285-0187)
Institutions
- University of Science and Technology of China (CN)
Publication Details
- Published
- 2025-05-25
- DOI
- https://doi.org/10.1109/iscas56072.2025.11043812
- Primary Topic
- Multilevel Inverters and Converters
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- National Natural Science Foundation of China