On October 26, 2026, Infineon announced that it will supply a 900V GaN (gallium nitride) monolithic bidirectional switch (BDS) to Enphase Energy. It will be used in the power modules of "IQ SST," the solid-state transformer (SST) that Enphase is developing for AI data centers. The two companies describe it as the world's first 900V GaN BDS.

A residential solar company moves into data center power

Enphase is known for microinverters for residential solar. According to its product page, IQ SST is a device that delivers 800VDC directly from the grid to AI compute racks, designed for 5MW per system, system efficiency above 98.5%, sub-millisecond response and 99.999% availability. It is modular, and battery storage can be integrated either close to the load or outside the white space.

In a conventional setup, medium-voltage AC is stepped down by a transformer and passes through UPS units and rectifiers before reaching the racks. An SST replaces this with high-frequency power conversion using semiconductors, handling voltage transformation and conversion to DC in one step. We covered SST orders for AI data centers in SiC solid-state transformer orders.

A bidirectional switch in a single device

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01

Voltage rating

900V. Extends GaN's operating voltage while keeping its high-frequency switching characteristics.

02

Structure

Monolithic BDS. Integrates bidirectional voltage blocking and current conduction in a single device.

03

Benefits

Power stages with fewer components, smaller magnetics, and fewer conversion stages.

04

Target voltages

Supports 800VDC distribution and a future move to 1500VDC distribution.

A typical power switch can block voltage in only one direction, so bidirectional operation requires combining two devices. A monolithic BDS does this in a single device. According to Infineon, its high blocking voltage lets designers handle higher system voltages with fewer conversion stages.

Hans van Antwerpen, senior vice president and CTO of Enphase, said GaN is already running in the field in the company's IQ9 microinverters, and that experience gave it confidence to scale up to megawatt-class systems. He said moving to 900V adds voltage headroom, allowing conversion stages to be removed and fewer components in the power path.

How it relates to SiC

Infineon said that while SiC (silicon carbide) is widely used for high-voltage power conversion, the 900V GaN BDS broadens the options for SSTs. It said the same device is also expected to be usable in three-phase commercial solar inverters at 480V in the US and 400V in other regions, reducing the number of switches and lowering losses and system cost.

What it means for design and procurement teams

  • SST semiconductors are no longer only SiC: SST products so far have mostly used SiC, as in the case of DG Matrix. With 900V GaN joining, SST procurement will start to involve comparing both SiC and GaN
  • Volume production timing is undecided: the 900V GaN BDS has not yet gone through volume qualification, and the announcement does not give a shipment date for IQ SST. It should be built into designs only after the volume qualification results are known
  • Parts can be shared with solar inverters: if the same device is used in commercial solar inverters, it can reach production volumes that data center demand alone would not. That helps supply stability and cost
  • More options for the move to 800VDC: power supply makers are bringing products for the transition to 800VDC to market. An SST that converts from the grid to 800VDC in a single unit is an option that could significantly change the equipment layout of the electrical room

Referenced Fact Cards