A Planar Transformer Design with Integrated Output Terminals for LLC DCX of Low-voltage and High-current Output

In this paper, a planar transformer design method with integrated output terminals is proposed for the vertical power delivery structure of high-performance AI computing processors. A flux-split winding is adopted for the primary side and half-turn windings are adopted for the secondary side, with which the transformer achieves a $24: 1$ ratio and its winding structure is simplified. Besides, with the proposed method, there is no need to lead the output terminals outside the transformer, which saves the effective footprint of the transformer and reduces terminal losses. A 48 V to 1 V LLC DCX prototype with 200 A output current is built to verify the design, which achieves a peak efficiency of $\mathbf{9 2. 2 \%}$.