What is a GaN bidirectional switch?

A GaN bidirectional switch is a gallium nitride power device that blocks voltage and conducts current in both directions. In a monolithic device, such as the 900 V CoolGaN BDS from Infineon, both functions sit in a single device, which simplifies the power stage and reduces the number of components.

What is a solid-state transformer?

Infineon describes solid-state transformers as an emerging key building block for next-generation power distribution architectures, where efficiency, power density and reliability are critical requirements. The Enphase IQ Solid-State Transformer is the company's SST product for AI data centres, where power density, efficiency and uptime influence the economics of every megawatt deployed.

Why does a 900 V rating matter for GaN power conversion?

A higher blocking voltage lets designers address higher system voltages with fewer power conversion stages, which supports the move toward 800 V and future 1,500 VDC power distribution. Enphase says 900 V adds voltage headroom while retaining high-frequency switching, and lets it keep components rated below 1 kV while reducing the number of converters and components in the power path.

Is the 900 V GaN bidirectional switch in production yet?

The 900 V GaN bidirectional switch devices have been successfully tested and are being integrated into Enphase IQ SST product development. Production qualification is expected to follow. The two companies have already partnered on 650 V GaN bidirectional switch technology in Enphase IQ9 Microinverters.

How does a 900 V GaN bidirectional switch sit alongside silicon carbide in solid-state transformer designs?

Infineon says silicon carbide is widely used in high-voltage power conversion and that the new CoolGaN 900 V monolithic BDS expands the range of available solutions for solid-state transformer architectures that benefit from high-frequency operation and integrated bidirectional switching. Enphase says the 900 V devices let it continue using components rated below 1 kV, which expands design options towards high-performance power conversion typically governed by silicon carbide.

What does a 900 V GaN bidirectional switch change in a medium-voltage solid-state transformer and its DC bus?

Enphase says a medium-voltage input can be handled by fewer inverters connected in series while retaining the low switching losses and intrinsic bidirectionality of GaN BDS. Fewer building blocks means lower system-level losses at the same input current, fewer components in the power path and a lower total switch count. On the DC side, Enphase says higher-voltage unidirectional switch devices allow power to be generated at a unipolar 800 V in place of split ±400 V buses, and support future 1,500 VDC bus architectures through split ±750 V generation with fewer switches and lower bridge losses.

What field experience supports Enphase using GaN at megawatt scale?

Enphase says GaN HEMT technology already operates in Enphase IQ9 Microinverters in the field, and that it is among the first to bring 650 V GaN BDS devices into volume production power electronics. Infineon says the two companies have already partnered on 650 V GaN BDS technology for IQ9. Hans van Antwerpen of Enphase said that field experience gave the company confidence to deploy GaN in megawatt-scale systems.

900 V GaN bidirectional switch from Infineon for Enphase

Q: Who is behind the 900 V GaN bidirectional switch?

Infineon supplies the 900 V CoolGaN BDS devices. Enphase led development and system-level demonstration, building on more than ten years of in-house GaN research, with device technology and engineering support from Infineon. Adam White is division president of Power Systems at Infineon, and Hans van Antwerpen is senior vice president and chief technology officer at Enphase Energy.

Rows of server racks in a data centre hall beside a floor-standing power cabinet, the kind of setting for 900 V GaN bidirectional switch technology in power conversion.

Fewer converters in the power path is the aim of 900 V GaN bidirectional switches in data centre transformers

(Image courtesy of Infineon)

Infineon will supply what it describes as the world’s first 900 V GaN bidirectional switch devices to Enphase Energy, which will deploy them in the power modules of its solid-state transformer for AI data centres. The CoolGaN 900 V monolithic BDS adds an option alongside the silicon carbide widely used in high-voltage conversion, and Enphase is now integrating the successfully tested devices into IQ SST development ahead of production qualification.

A 900 V GaN bidirectional switch in a single device

Monolithic GaN bidirectional switches block voltage and conduct current in both directions within a single device, which simplifies the power stage and supports the high-frequency operation that raises power density and shrinks magnetics. The 900 V GaN bidirectional switch lets designers address higher system voltages with fewer conversion stages, in line with the industry’s move toward 800 V and future 1,500 VDC distribution.

Enphase led the development and system-level demonstration, building on more than ten years of in-house GaN research, with device technology and engineering support from Infineon. The two companies have already partnered on 650 V GaN BDS technology in Enphase IQ9 microinverters.

Fewer converters from a 900 V GaN bidirectional switch

Hans van Antwerpen, senior vice president and chief technology officer at Enphase, said field experience with GaN in IQ9 microinverters is what gave the company confidence to use it at megawatt scale. Moving to 900 V adds voltage headroom while keeping high-frequency switching, he said, and it reduces the number of converters and components in the power path, which he links to higher efficiency and improved system reliability.

Adam White, division president of Power Systems at Infineon, framed the 900 V CoolGaN BDS as an extension of the applications where customers can use the efficiency and power density of GaN, bringing the technology into a voltage class that opens new possibilities for high-performance power conversion.

Solar inverters and production qualification

Enphase expects the same device technology to benefit commercial solar inverters by enabling three-phase, line-to-line designs for 480 V applications in the United States and 400 V applications in other regions, with fewer switches, lower losses and lower system cost. The 900 V GaN bidirectional switch devices have been tested successfully and are going into IQ SST product development, with production qualification expected to follow.

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Enphase and Infineon take GaN to 900 V for AI data centres

A 900 V GaN bidirectional switch in a single device

Fewer converters from a 900 V GaN bidirectional switch

Solar inverters and production qualification