High-density AI server racks need efficient power conversion and reliable backup during load fluctuations. A new three-phase reference design combines advanced switching topologies, digital control and integrated energy buffering.
The 27 kW three-phase power supply unit (PSU) by Infineon Technologies AG is designed for next-generation artificial intelligence (AI) servers and high-density data centre racks that require efficient power conversion and stable operation during rapid changes in GPU demand. The design meets Open Compute Project (OCP) Open Rack V3 (ORV3) requirements and supports emerging 800V DC and ±400V DC power architectures.
It achieves peak efficiency exceeding 98% at 480V AC input and 50% load, helping reduce conversion losses and heat generation in densely packed server racks. Its power density of 116W/in³ exceeds the ORV3 minimum requirement of 94W/in³, enabling more power delivery within limited rack space.
It combines 650V CoolSiC and CoolMOS MOSFETs, EiceDRIVER gate drivers, XENSIV current sensors and PSoC microcontrollers. Its five-level active neutral-point-clamped (ANPC) power factor correction (PFC) stage works with a three-level LLC resonant converter to support efficient power conversion. The integrated planar magnetic structure enables a compact, modular high-frequency transformer design.
The key features are:
- Five-level ANPC topology for power factor correction.
- Three-level LLC resonant conversion architecture.
- 20ms integrated energy-buffer hold-up time.
- Integrated planar magnetic transformer structure.
- Operating ambient temperature range of −5°C to 45°C.
For improved power continuity, the PSU incorporates an energy buffer that provides 20 milliseconds of hold-up time during short grid disturbances. It also helps manage rapid GPU load changes, reducing the need for a separate capacitor bank unit (CBU). This can simplify rack power infrastructure and save installation space.
Digital control of the PFC and LLC stages helps the supply respond to fast load transients associated with AI workloads. A programmable power control accelerator (PPCA), integrated into the PSoC Control C3 Performance Line microcontroller, enables precise current and voltage regulation with fast dynamic response.
It supports three-phase input voltages from 311V to 528V AC, making it adaptable to different grid standards. Its input-current total harmonic distortion is low, while its power factor exceeds 0.99 across most of the operating load range. It is specified for ambient temperatures from −5°C to 45°C.
The solution targets server original equipment manufacturers (OEMs) and original design manufacturers (ODMs) developing AI computing infrastructure. By combining high efficiency, compact power conversion and transient-load management, it can help engineers develop scalable power systems for increasingly demanding AI data centres.
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