Companies collaborate on next generation 800V HVDC architecture

Navitas Semiconductor is collaborating with NVIDIA on its next-generation 800V HVDC architecture to support ‘Kyber’ rack-scale systems powering their GPUs, such as Rubin Ultra, allowed by GaNFast and GeneSiC power technologies.

NVIDIA’s next-generation 800VDC architecture aims to establish high-efficiency, scalable power delivery for next-generation AI workloads, ensuring greater reliability, efficiency, and decreased infrastructure complexity.

Today’s existing data centre architecture uses conventional 54V in-rack power distribution and is limited to a few hundred kilowatts (kW). Bulky copper busbars are needed to transfer this low-voltage electricity from the rack-mounted power shelves to the compute trays. As power increases above 200kW, this architecture runs into physical limits due to power density, copper requirements, and reduced system efficiency.

Modern AI data centres require gigawatts (GW) of power for the increasing demand for AI computation. Nvidia’s approach is to directly convert the 13.8kV AC grid power to 800V HVDC at the data centre perimeter using solid-state transformers (SST) and industrial-grade rectifiers, eradicating several AC/DC and DC-DC conversion steps, maximising efficiency and reliability.

Due to the higher voltage level of 800V HVDC, the thickness of copper wires can be decreased by up to 45% due to I2R losses, where the same amount of power can be delivered with increased voltage and lower current. Using a traditional 54V DC system, over 200kg of copper would be required to power a 1MW rack, which is not sustainable for next-generation AI data centres with GW power demand.

The 800V HVDC directly powers the IT racks (eradicating the necessity for additional AC/DC converters) and is converted by DC-DC converters to lower voltages, which will drive GPUs, such as the Rubin Ultra.

Navitas is an established leader in AI data centre solutions allowed by GaN and SiC technology. The high-power GaNSafe power ICs integrate control, drive, sensing, and critical protection features, allowing unprecedented reliability and robustness. GaNSafe is the world’s safest GaN with short-circuit protection (max latency of 350ns), 2kV ESD protection on all pins, elimination of negative gate drive, and programmable slew rate control. All these features are controlled with four pins, allowing the package to be treated like a discrete GaN FET, eliminating the need for a VCC pin.

Furthermore, the company offers a family of medium voltage (80-120V) GaN devices, which have been optimised for secondary side DC-DC conversion, delivering high speed, high efficiency, and a small footprint for AI data centre PSUs with outputs of 48V-54V.

Enabled by 20 years of SiC innovation leadership, GeneSiC proprietary ‘trench-assisted planar’ technology delivers world-leading performance over temperature, providing high-speed, cool-running operation for high-power, high-reliability applications. G3F SiC MOSFETs deliver high-efficiency with high-speed performance, enabling up to 25C lower case temperature, and up to 3x longer life than SiC products from other vendors.

Offering the industry’s widest voltage range – spanning from 650V to ultra-high voltages of 2.3kV to 6.5kV - the SiC technology has been implemented in multiple projects for MW energy storage and grid-tied inverters in collaboration with the Department of Energy (DoE).

In August 2023, Navitas introduced a high-speed, high-efficiency 3.2kW CRPS, achieving a 40% smaller size than best-in-class, legacy silicon solutions for power-hungry AI and Edge computing. This was followed by the world’s highest power density, 4.5kW CRPS, achieving a ground-breaking 137W/in3 and an efficiency of over 97%. In November 2024, the company released the world’s first 8.5kW AI data centre power supply, powered by GaN and SiC that could meet 98% efficiency, complying with the Open Compute Project (OCP) and Open Rack v3 (ORv3) specifications. Additionally, it developed IntelliWeave, an innovative, patented digital control technique that, when combined with high-power GaNSafe and Gen 3-Fast SiC MOSFETs, enables PFC peak efficiencies of 99.3% and reduces power losses by 30% compared to existing solutions.

“We are proud to be selected by NVIDIA to collaborate on their 800 HVDC architecture initiative. Our latest innovations in high-power GaN and SiC technologies have seen world firsts and have created new inflections into markets such as AI datacentres and electric vehicles,” said Gene Sheridan, CEO and co-founder of Navitas. “With our wide portfolio range, we can support NVIDIA’s 800V HVDC infrastructure, from grid to the GPU. We appreciate that NVIDIA recognizes our technology and commitment to driving the next generation of data centre power delivery.”

NVIDIA’s 800V HVDC architecture will improve end-to-end power efficiency by up to 5%, lower maintenance costs by 70% (due to fewer PSU failures), and lower cooling costs by directly connecting HVDC to the IT and compute racks.