Centrally Built-in Power-Terminal Matrix Transformer for Vertical Power Delivery in LLC DCX

In low-voltage, high-current LLC-DCX converters, vertical power delivery (VPD) tightly couples power terminal placement with transformer geometry, constraining achievable current density and scalability. This paper proposes a centrally built-in power-terminal (CBiPT) matrix transformer, in which the power terminals are embedded within the transformer to reduce external PCB power routing. The proposed structure supports both horizontal and vertical matrix extension, enabling high turns ratio and high current density while maintaining a compact footprint. The proposed structure is designed, optimized, and thermally analyzed, based on which a 48 V-0.75 V LLC-DCX prototype is built. The prototype achieves a peak efficiency of 94.2%. Under immersion liquid cooling, it delivers up to 800 A at full load, corresponding to a current density of 1.12