Overcoming AI challenges with highest power density data centre design

Navitas Semiconductor has released its 4.5kW AI data centre power supply reference design with optimised GaNSafe and Gen-3 'Fast' (G3F) SiC power components. The optimised design facilitates the world's highest power density with 137W/in3 and over 97% efficiency.

Next-generation AI GPUs like NVIDIA's Blackwell B100 and B200 each demand over 1kW of power for high-power computation, 3x higher than traditional CPUs. These new demands drive power-per-rack specifications from 30-40kW up to 100kW.

The company announced its AI Power Roadmap in March 2024, showcasing next-generation data centre power solutions for the growing demand for AI and HPC systems. The first design was a GaNFast-based 3.2kW AC/DC converter in the CRPS form factor, as defined by the hyperscale Open Compute Project. The 3.2kW CRPS185 (for 185mm length) facilitated a 40% size reduction versus the equivalent legacy silicon approach and easily exceeded the 'Titanium Plus' efficiency benchmark, critical for data centre operating models and a requirement for European data centre regulations.

The latest 4.5kW CRPS185 design demonstrates how new power ICs and MOSFETs allow the world's highest power density and efficiency solution. At the heart of the design is an interleaved CCM totem-pole PFC utilising SiC with full-bridge LLC topology with GaN, where the fundamental strengths of each semiconductor technology are exploited for the highest frequency, coolest operation, optimised reliability and robustness, and highest power density and efficiency. The 650V G3F SiC MOSFETs feature 'trench-assisted planar' technology, which delivers world-leading performance over temperature for the highest system efficiency and reliability in real-world applications.

For the LLC stage, 650V GaNSafe power ICs are ideal and unique in the industry with integrated power, protection, control, and drive in an easy-to-use, robust, thermally-adept TOLL power package. Also, GaNSafe power ICs deliver extremely low switching losses, with a transient-voltage capability of up to 800V, and other high-speed advantages such as low gate charge (Qg), output capacitance (COSS), and no reverse-recovery loss (Qrr). High-speed switching decreases the size, weight, and cost of passive components in a power supply, such as transformers, capacitors, and EMI filters. As power density increases, next-gen GaN and SiC enable sustainability benefits, particularly CO2 reductions due to system efficiency increases and 'dematerialisation'.

The 3.2kW and 4.5kW platforms have already generated notable market interest, with over 30 data centre customer projects in development expected to drive millions in GaN and SiC revenue, ramping from 2024 into 2025.

The company's AI data centre power supply reference designs dramatically accelerate customer developments, minimise time-to-market, and set new industry benchmarks in energy efficiency, power density and system cost, enabled by the power ICs and MOSFETs. These system platforms include complete design collateral with fully tested hardware, embedded software, schematics, BOM, layout, simulation, and hardware test results.

"AI is dramatically accelerating power requirements of data centres, processors, and anywhere AI is going in the decades to come, creating a significant challenge for our industry. Our system design centre has stepped up to this challenge, delivering a 3x increase in power in less than 18 months," said Gene Sheridan, CEO of Navitas Semiconductor. "Our latest GaNFast technology, combined with our G3F SiC technology, are delivering the highest power density and efficiency the world has ever seen…the perfect solution for the Blackwell AI processors and beyond."