Power supply reference design delivers high power density

Navitas Semiconductor has announced its 4.5-kW AI data center power supply reference design, with GaNSafe and Gen-3 ‘Fast’ (G3F) silicon-carbide (SiC) power components. The company claims the optimized design enables the highest power density with 137 W/in³ and over 97% efficiency.

The reference design targets next-generation AI GPUs like Nvidia’s Blackwell B100 and B200 that require over 1 kW of power for high-power computation, which is 3× higher than traditional CPUs. These new demands are driving power-per-rack specifications from 30-40 kW up to 100 kW, Navitas said.

Navitas released its AI Power Roadmap in March 2024, highlighting its next-generation data center power solutions for AI and high-performance computing (HPC) systems. The first design was a GaNFast-based 3.2-kW AC/DC converter in the common redundant power supply (CRPS) form factor, as defined by the hyperscale Open Compute Project. The 3.2-kW CRPS185 (185 mm length) enabled a 40% size reduction compared with the equivalent legacy silicon approach and exceeded the Titanium Plus efficiency benchmark, which is used for data center operating models and a requirement for European data center regulations.

(Source: Navitas Semiconductor)

The 4.5-kW CRPS185 design demonstrates how new GaNSafe power ICs and GeneSiC Gen-3 ‘Fast’ (G3F) MOSFETs enables the industry’s highest power density and efficiency solution, Navitas said.

The design uses an interleaved CCM totem-pole PFC using SiC with full-bridge LLC topology with GaN, leveraging each technology’s advantages in areas such as frequency, thermal operation, reliability, power density and efficiency. The 650-V G3F SiC MOSFETs feature trench-assisted planar technology, delivering high performance over temperature for high system efficiency and reliability in real-world applications.

For the LLC stage, 650-V GaNSafe power ICs offer integrated power, protection, control and drive in a TOLL power package. They also offer extremely low switching losses, with a transient-voltage capability up to 800 V, and other high-speed advantages such as low gate charge (Qg), output capacitance (C_OSS) and no reverse-recovery loss (Qrr). The benefits of high-speed switching are a reduction in the size, weight and cost of passive components, such as transformers, capacitors and EMI filters, in a power supply.

In addition, GaN and SiC enable sustainability benefits, specifically CO₂ reductions due to system efficiency increases and dematerialization, as power density increases, the company said.

Navitas said the 3.2-kW and 4.5-kW platforms have already generated significant market interest with over 30 data-center customer projects in development. These system platforms include complete design collateral with fully tested hardware, embedded software, schematics, bill of materials, layout, simulation and hardware test results. The reference designs are available to qualified customers.