Infineon Will Supply Enphase 900 V GaN Switches for Data Center SSTs
Infineon and Enphase call their 900 V CoolGaN bidirectional switches the first monolithic GaN parts at that rating. They have passed testing, but production qualification and a commercial date are still open.
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Infineon is to supply Enphase with 900 V GaN bidirectional switches, which the companies call a world first.
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Infineon Technologies is to supply Enphase Energy with 900 V gallium nitride (GaN) bidirectional switches for solid-state transformers (SSTs) in AI data center power systems, Semiconductor Today reported on Oct. 26. The companies describe the CoolGaN devices as the first monolithic GaN bidirectional switches at that voltage rating, according to eeNews Europe and Semiconductor Today.
An SST uses power electronics to convert and manage voltage in place of a conventional transformer. Enphase is putting the 900 V parts into its IQ Solid-State Transformer, which it develops for AI data centers. The devices have completed initial testing and are being integrated into that development program, the reports say, with production qualification to follow. The companies have not announced a timetable for commercial availability.
Each monolithic switch combines bidirectional voltage blocking and current conduction in a single device, the companies say, which they say can reduce the number of components in a power stage. Enphase's chief technology officer, Hans van Antwerpen, said the 900 V rating gives more voltage headroom while keeping high-frequency switching, and lets the company remove converter stages. Enphase says fewer stages and parts translate to higher efficiency and reliability; that is its claim, not a measured result, and no efficiency figure has been published.
Where it fits in the 800 VDC shift
The companies say the higher blocking voltage supports the industry move toward 800 V and future 1,500 VDC distribution. Voltgrid has followed the Infineon side of that shift: its work with NVIDIA on GaN for 800 VDC racks, where the release gave no customer or launch date, and its plan to spend 1.1 billion euros on a 300 mm GaN line in Villach, with production targeted for the end of 2027. On the demand side, Vantage has secured solid-state transformer capacity for 800 VDC AI racks.
Enphase's SST part steps up from the 650 V rating in IQ9 microinverters to 900 V, tested but not yet qualified for production.
Illustration (AI-generated)
The new fact is a named SST developer and a higher-voltage part. Enphase led the system-level development and demonstration, building on more than ten years of its own GaN research, with device technology and engineering support from Infineon. The two already work together on 650 V GaN bidirectional switches used in Enphase's IQ9 microinverters. The companies also say the 900 V devices could support three-phase commercial solar inverters at 480 V in the United States and 400 V elsewhere.
How a bidirectional GaN switch cuts stages
A bidirectional switch must block voltage in both directions and pass current either way, a job conventional designs spread across several devices. Infineon's CoolGaN part is rated 900 V, up from the 650 V version already used in Enphase's IQ9 microinverters, Semiconductor Today reported.
The higher rating lets a design handle higher system voltages with fewer conversion stages, the companies say, which fits racks moving toward 800 V and later 1,500 VDC distribution. Fewer stages would mean fewer parts in the power path, but no efficiency figure has been published.
What is not confirmed yet
Silicon carbide is widely used in high-voltage power conversion, and the companies position GaN as an added option for SST designs that benefit from high-frequency switching, not as a replacement. No order size, price, efficiency result, qualification date or data center customer for Enphase's SST has been disclosed. The world-first claim comes from the two companies themselves.
