IN Brief:
- M-CRPS power supply design provides 5.6kW in a 185mm modular format.
- Infineon reports 170W/in³ power density and more than 98% peak efficiency.
- Digital control, thermal performance and load transients are central evaluation criteria.
Infineon has introduced a 5.6kW modular common redundant power-supply reference design for enterprise servers and edge AI equipment. It specifies a 54V output, power density of about 170W per cubic inch and peak efficiency above 98%, figures intended to illustrate the potential of a compact conversion architecture. The efficiency figure is a reported peak operating point rather than a guaranteed full-load result across different ambient temperatures, input voltages or rack configurations. The reference design is an evaluation resource, not a confirmed installation across a commercial server fleet.
The design combines several conversion functions rather than relying on a single semiconductor technology. An AC-input power supply must shape its input current, create a regulated DC output, and maintain stable delivery when a server changes load rapidly. Infineon describes a three-level flying-capacitor power-factor-correction stage and downstream resonant conversion, drawing on its silicon carbide, gallium nitride and control components. Device selection at each stage reflects its voltage stress, required switching frequency, conduction losses and thermal limits.
Power density is a particularly relevant measure in data-centre equipment because each occupied millimetre competes with cooling channels, connectors and service clearances. A smaller supply can release space within a chassis, but shrinking the magnetic components and heatsinking increases the importance of airflow and material temperature limits. Engineers must examine the shape of the power-density curve under different load levels. Server workloads fluctuate, and the converter’s efficiency at part load can influence annual electricity consumption as much as its best published figure.
The reference design targets an efficiency profile aligned with demanding standards including 80 PLUS Ruby and China’s GB 20943-2025. That wording describes a design target, not certification of every assembled unit. Independent testing and formal compliance depend on the final enclosure, fan arrangement, input conditions and measured operating points. Switching noise and conducted emissions also have to be evaluated after the supply is integrated with boards and cabling, particularly where high switching frequencies produce compact but sensitive layouts.
Power continuity is another distinct design problem. Hold-up energy storage allows a supply to ride through short disturbances in its input without immediately dropping the output rail. Designers must calculate the permitted interruption, capacitance, inrush stresses and behaviour when power is restored.
In redundant server architectures, multiple supplies may share load and be exchanged during maintenance. Protection and current-sharing behaviour become important when a fault affects one module or the rack suddenly loses a source.
At the output, a 54V bus reduces current relative to a lower-voltage supply for the same delivered power, potentially easing distribution losses before point-of-load conversion. It also requires suitable connector clearances, protection and downstream regulators. Digital control can support measurement and coordinated response, but the stability of each control loop needs to be tested across input, output and temperature extremes. Semiconductor switching efficiency cannot compensate for poor control during rapidly changing accelerator demand.
There are also mechanical and servicing questions. Redundant power modules are expected to operate within a defined connector interface and may be inserted or removed according to the equipment’s maintenance procedure. A high-density design must preserve acceptable touch temperatures, airflow clearance and insulation even when neighbouring units operate near maximum output.
Fans and associated controls contribute their own electrical load and failure modes. Testing should include blocked-airflow, high-inlet-temperature and abnormal-load cases rather than judging the supply only under controlled laboratory cooling. These tests should also establish how the control circuitry behaves after repeated load steps, because efficient steady-state conversion offers limited value if transient voltage excursions affect downstream processors.
Infineon’s 5.6kW design gives power-supply engineers a concrete topology to assess against space, efficiency and thermal constraints. The most informative follow-up evidence will be measured performance curves, transient-response results and compliance testing in representative enclosures. Until those are available for a given implementation, peak efficiency and power-density specifications should remain attributed to the reference configuration rather than generalised to every AI server supply.
