Infineon 24kW SiC BBU AI Data Center Power Reference Design

A Breakthrough in High-Voltage Power Delivery

Infineon Technologies AG has introduced a reference design for a 24kW battery backup unit (BBU) for AI data centers. It targets emerging high-voltage (HV) DC bus architectures. The key differentiator is direct operation from a battery stack to an 800V DC bus. It achieves this using silicon carbide (SiC) devices.

Unmatched Density and Efficiency for AI Demands

The design reaches 450W/in³ power density and over 99% efficiency. It fits in the same footprint as older, lower-voltage BBU systems. This helps remove a bottleneck as data centers move to higher-voltage DC distribution to cut losses.

Magdalene Boebel, Senior VP at Infineon, said: “Powering AI at scale requires optimizing the entire power delivery chain.” They added that the 24kW HV BBU reference design sets a new benchmark for an integrated solution.

Advanced Architecture for Superior Performance

Innovative Multi-Level Design

The core uses a multi-level, multi-phase architecture with stacked, interleaved boost and buck stages. This reduces magnetics size without extra “flying” capacitors. A shared switching leg enables zero-voltage switching across the operating range. The result is low ripple, integrated magnetics, and fast response to load steps.

Compact and Integrated Module

The module measures 112mm × 88mm × 118mm. It integrates a 24kW main stage and a 2.4kW auxiliary supply. Charger and discharger sections share parts such as the EMI filter and protection circuits. This lowers total part count. The design also supports seamless switching and hot-swap.

The Heart of the System: CoolSiC MOSFET Technology

The DC-DC stage centers on Infineon’s CoolSiC MOSFET IMT65R033M2H. It is a 650V device qualified for bidirectional flow in HV BBU use cases. Low switching and conduction losses help deliver >99% efficiency and reduce rack-level heat.

During grid events, it transfers energy quickly between the HV bus and the battery. This extends server hold-up time. High-temperature capability and robust packaging improve tolerance to spikes and thermal stress.

Complete System Solution from Infineon

Infineon positions this as a full bill-of-materials reference design. It includes CoolSiC MOSFET 650V Gen 2 devices, gate drivers, current sensors, a PSOC microcontroller, and a CoolSET IC for the auxiliary supply.

Additional Design Highlights

Other features include lower electrical noise and three power cards that serve as DC rail connectors and structural supports.

Driving the Future of Data Center Power

Higher-voltage DC bus architectures improve efficiency at both rack and facility levels. BBUs are essential to maintain uptime for AI servers. This 24kW design shows how SiC-based bidirectional DC–DC conversion can meet demanding density, efficiency, and reliability targets. Infineon’s portfolio spans silicon, SiC, and GaN across the power chain.

Related Developments

• Infineon releases 12kW high-density PSU reference design for AI data centers and servers
• Infineon collaborates with NVIDIA on industry-first 800V power delivery architecture for AI data center server racks
• Infineon unveils roadmap for power supply units in AI data centers