T17.5 - Optimal Design of a 3-Cell Matrix Transformer for 1-MHz GaN LLC Converter Supporting 400-V/800-V Data Center Systems

Wednesday, March 25, 2026

2:50 PM - 3:10 PM CT

Location: 214A

Technical Lecture Presenter(s)

Shuyu Zhang (she/her/hers)

University of California, Berkeley

Presentation Paper

Co-Author(s)

Yifan Chen (he/him/his)

Huazhong University of Science and Technology
XY

Xingyuan Yan

Huazhong University of Science and Technology
JD

Jialong Dou

Huazhong University of Science and Technology
ZW

Zhiqiang Wang

Huazhong University of Science and Technology

This article presents a gallium nitride (GaN) based 1-MHz 12V/480W LLC converter employing a 3-cell matrix transformer optimized for the emerging 800-V/400-V datacenter bus. While matrix transformer with 4-cell arrays have been thoroughly investigated, flux cancellation and winding layout for odd-numbered cell arrays remain unaddressed. To fill this gap, two distinct flux path and winding patterns are proposed and compared; the preferred one achieves optimal flux balance and shrinks the print circuit board (PCB) footprint by 40 %. A core loss model for the proposed magnetic core is developed for further winding optimization. To achieve compatibility with both 400-V and 800-V architectures, a stacked bridge structure with two selectable switching modes is employed on the primary side. Finally, a 1 MHz GaN-based prototype is built and tested.