Electrical equipment manufacturer Enphase Energy has partnered with German semiconductor firm Infineon Technologies to deploy what it calls “the world’s first” 900 Volt gallium nitride (GaN) monolithic bidirectional switch (BDS) devices within Enphase's solid-state transformer power modules.

The partners claim the deployment will play a crucial role in scaling Enphase’s IQ Solid-State Transformer (IQ SST), designed for the AI data center sector.

According to Enphase, the BDS devices will allow Enphase to continue using components rated below 1kV, expanding design options for high-performance power conversion that typically rely on silicon carbide (SiC) technology. The company also claims that, within an SST, the switches will reduce switching losses and require fewer components in the power path.

The company said that on the DC side, higher-voltage unidirectional switch (UDS) devices would enable unipolar 800V power generation rather than split +/-400V buses, and support future 1,500VDC bus architectures through split +/-750V generation with fewer switches and lower bridge losses.

"Enphase asks more of our technology than almost anyone, and medium-voltage solid-state transformers are exactly where high-voltage GaN proves its value," said Johannes Schoiswohl, senior vice president and head of GaN Systems Business Line at Infineon. "Moving past 650V lets system designers strip cost and loss out of the architecture rather than optimizing around it."

"GaN is not new to us. It has been running in Enphase IQ9 Microinverters in the field, and that field data is why we trust it in a megawatt-class system," said Hans van Antwerpen, senior vice president and chief technology officer at Enphase Energy.

"Moving to 900V gives us more voltage headroom without giving up high-frequency switching, and it allows us to stay with components rated below 1kV while reducing the number of converters in the system. Fewer parts in the power path means higher efficiency and fewer things that can fail."

The 900V GaN BDS devices have been successfully tested and are now being integrated into IQ SST development builds, with production qualification expected to follow.

SSTs are growing in popularity across the data center sector, with several major firms signing deals with providers over recent months. Earlier this month, Vantage inked a deal with SST manufacturer Heron Power to secure more than 1GW of the company’s SST’s to deploy across its hyperscale data center portfolio. Heron has also partnered with Crusoe.

Infineon has also partnered with other manufacturers on the technology. Last month, the firm signed a deal with Eaton to provide the company with silicon carbide (SiC) power devices for deployment in the power management firm’s medium-voltage SST platform.