Onsemi's 1MW rack argument rests on a single circuit-breaker measurement

A power engineer specifying a 200kW rack is working inside a volume that was set when racks drew 60kW ^[3]. Onsemi's one quantified EPP result is a circuit breaker. In an early solid-state circuit-breaker design, the company says the part came out about 50 percent smaller and 20 percent cooler than existing designs ^[8]. That saving is worth having in a space that cannot grow, though it covers one part in one early design and Onsemi measured it itself. The company did not publish a rack-level power density figure ^[3].

Dinesh Ramanathan, Onsemi's SVP of corporate strategy, makes his case at the level of the whole rack. "The space in the rack isn't changing, but the amount of power that rack is going to end up consuming is increasing by a dramatic amount," he said ^[4]. He also said: "If we can't increase the power density across the entire rack, we'll never be able to reach 1MW" ^[5]. His own numbers size that job. From 60kW to 1MW is 16.7 times the power in the same space, and the first leg, 60kW to 200kW, is 3.3 times of it inside two years ^[1][2].

The method is to stop treating the package as a separate thing. Onsemi cuts a cavity into a silicon wafer and places the die inside it, Ramanathan said, so silicon, silicon carbide and vertical gallium nitride can be interconnected in what the company calls a "highly integrated wafer-level architecture" ^[6]. FETs, drivers and controllers can sit in one package co-optimized for electrical, thermal and mechanical performance ^[7]. "By reducing packaging overhead and using the full EPP footprint to conduct heat, EPP can support more compact power systems, improve thermal management and enable greater power density in AI infrastructure," the company said in a statement ^[10]. It runs on Onsemi's standard 12-inch silicon wafer lines ^[9].

The customer a buyer can check is an automaker. Subaru has a deployment partnership giving it early access to engineering samples, simulation models and technical expertise ^[11]. Ramanathan said Onsemi is also working with an industrial company and an AI data center company, and that he was not in a position to name them ^[12]. He said Onsemi has shown those customers what the technology can do and is working towards getting the product into revenue in the 2027 time frame, so it is sampling customers this year ^[13]. Qualification is expected in Q1, followed by general availability ^[14].

Two questions sort any power-density pitch into something you can act on. Where in the power path does the quantified saving land: at protection, at conversion, or at the point of load. And who measured it: the vendor in simulation, or a customer in a deployed rack. EPP's published number sits at protection, measured by Onsemi, in a design the company itself calls early ^[8]. That is where a new architecture normally starts. For anyone taking samples before the Q1 qualification, the useful ask is how many of a rack's watts pass through EPP silicon and how many millimetres that frees up, because the 60kW-to-200kW step gets engineered before EPP reaches revenue ^[3][13].