Onsemi ties its GaN ramp to Nvidia's 2027 move to 800-volt racks

Most operators have only handled gallium nitride inside a charging brick. GaN transistors are at present found mostly in chargers, for everything from phones to electric vehicles, according to DCD ^[4]. "The world has been expecting GaN to ramp into the server and telecom space since we started talking about this technology around 10 - 15 years ago," Antoine Jalabert, vice president of Onsemi's GaN division, told DCD ^[5]. "Instead, it ramped somewhere nobody was looking: in charging adapters," he said ^[6].

He now puts a date on the server ramp. "I would say 2026/27 will really be when we see GaN ramp into mass production," Jalabert said ^[1]. He credits Nvidia: "When you look at Nvidia's roadmap, there's no other way than to use GaN that will allow you to reach those kinds of power densities" ^[2]. As DCD describes it, Nvidia's commitment concerns voltage. Starting in 2027, Nvidia is moving toward 800-volt direct current rack power to support racks of 1MW and beyond ^[3]. The claim about GaN is Jalabert's, and his division sells it ^[2]. Onsemi is one of a modest number of companies offering GaN power semiconductors ^[16].

For the person buying racks, the change is small. Jalabert said servers will not become GaN-based. The material goes into transistors and some components inside power supply units ^[12]. "You're not going to replace everything silicon or silicon carbide with GaN, but today, with AI, for example, where we see value with GaN, it's with what we call the high voltage primary side intermediate bus converter," he said ^[11]. GaN loses less energy to heat than silicon or silicon carbide during power conversion, per DCD ^[19]. Jalabert said the payoff is size: "when you have a system that works at a higher frequency, especially switch-mode power supplies, the smaller that system can be" ^[14].

The voltages show where the timing gets tight. Commercially available lateral GaN currently reaches 650 volts at the top end, according to DCD ^[10]. Nvidia's 800-volt bus is 150 volts above that ^[15]. For 800-volt DC-DC converters, Onsemi is pitching its vertical GaN, which the company says handles more than 1,200 volts ^[9]. Onsemi unveiled it in October 2025. It is made at the company's fab in Syracuse, New York, and is still about a year from mass production ^[7][8]. Onsemi's lateral work with GlobalFoundries starts at 650 volts ^[10].

Jalabert's ramp window and Nvidia's start date overlap in 2027 ^[1][3]. DCD did not report volumes or prices for Onsemi's GaN parts. The claim that Nvidia's racks need GaN comes from Jalabert, not from Nvidia ^[2][3].

A team planning 2027 capacity needs to know whether the plan depends on 800-volt racks at all, and whether the power-supply vendor will name the device in the primary-side converter and say it is in volume production. Without 800-volt racks, a plan can treat GaN as a supplier's efficiency claim. If the racks are 800-volt, a named part already in volume makes it ordinary procurement, and a part still short of volume makes power conversion a schedule item. The question for the vendor then is what goes into that converter if the GaN ramp slips a year.