Vertically Stacked Dual-Bus DC–DC Converter for Data Center High-Current Power Delivery

Increasing power consumption in data centers is pushing the dc distribution networks system for high efficiency and power density, redundancy, and low-cost design. To comply with this trend, this article presents a dual-bus 48 V to 12/4 V back-to-back converter for high-current power delivery in data centers, designed with a vertical assembling structure. This converter is realized with a modular approach consisting of a four-phase interleaved buck converter cascaded with a switched capacitor voltage selector. The four buck converters are connected in parallel and use an interleaved control modulation to distribute the current, providing a stable voltage to the switched capacitor converter in the second stage. Four <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">mosfet</small>s are paralleled in each leg of the switched capacitor converter to withstand the high output current. The architecture has high modularity and scalability ensuring low voltage drop and redundant operations. A vertically stacked prototype with a 200 A maximum output current is tested and discussed in this article. A small equivalent output resistance of 0.34 m<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\Omega$</tex-math></inline-formula>, reduced cost of 0.82 €/A, and DOE Level VI efficiency compliance has been achieved.