The design showcases how wide-bandgap devices, multi-level PFC and high-frequency LLC conversion can deliver record efficiency and compactness for next-generation AI servers and data-centre racks.
The semiconductor company Infineon Technologies AG has unveiled a new 12 kW high-density power-supply-unit (PSU) reference design aimed squarely at AI-data-centre and high-performance server environments. The design is built to meet the surging power-and-density demands of modern computing racks by combining best-in-class semiconductor technologies with advanced conversion topologies.
In this architecture, the front-end AC-DC stage employs a three-level flying-capacitor, interleaved power‐factor-correction (PFC) topology. This topology enables very high conversion efficiency (above 99 %) while also reducing the volume of magnetic components. Key to this performance is the use of silicon-carbide (SiC) MOSFETsInfineon’s CoolSiC devices which deliver superior switching behaviour and thermal performance compared with conventional silicon. On the DC-DC side, the design uses an isolated full-bridge LLC resonant converter leveraging planar high-frequency transformers and gallium-nitride (GaN) switches (Infineon’s CoolGaN portfolio). This stage achieves peak efficiency above 98.5 % while supporting very high switching frequency and compact form-factor. These two major conversion blocks combine to produce an exemplary power density of up to ~113 W/in³.
Beyond the raw topologies, the reference design incorporates a bidirectional energy-buffer stage integrated into the PSU topology. This buffer serves multiple functions: it meets the hold-up-time requirements typical of server racks without relying solely on bulky high-voltage bulk capacitance, and it introduces grid-shaping capability limiting the magnitude and rate-of-change of current drawn from the mains during transient events, thereby improving system reliability and reducing input stress.
From a systems perspective, the architecture supports large-scale data-centre power deployment by offering a compact, scalable form factor and high density. The utilisation of wide-bandgap technologies (SiC + GaN) alongside optimized silicon devices allows the design to deliver both efficiency and high power density key metrics for racks pushing toward multi-hundred-kilowatt loads. The roadmap for Infineon’s AI-PSU solutions spans from 3 kW through 8 kW and now to this 12 kW design, illustrating the evolution of topology, device integration and packaging to handle ever-higher power demands.For R&D engineers and hardware designers in the power-electronics domain, this reference design serves as a blueprint: how to integrate multi-level PFC, high-frequency resonant DC-DC, and wide-bandgap semiconductors while balancing hold-up, power density, thermal management and grid-interaction. Given the rapid growth of AI workloads and the associated increase in rack-level power budgets, designs like this help to reduce cooling overheads, board real-estate, and total cost of ownership over the lifetime of a server infrastructure.
The reference design sets a new benchmark for AI-centric power supplies by delivering industry-leading efficiency, high power density, and smart energy-buffering in a form factor ready for next-generation data-centre racks.Infineon Technologies AG has tested this reference design. It comes with a bill of materials (BOM), schematics, assembly drawing, printed circuit board (PCB) layout, and more. The company’s website has additional data about the reference design. To read more about this reference design, click here.
