Chip Startup Empower Secures $140 Million to Address AI Power Boom

Power startup Empower Semiconductor said it raised more than $140 million of fresh funding to scale up production of power-management ICs aimed at GPUs and other power-hungry AI chips.

The funding parlays a big bet that future advances in AI will depend as much on innovations in power electronics as improvements in computing or networking. The data centers driving the AI boom are suctioning up power at unprecedented rates, pushing the grid to its limits and contributing to rising electricity costs.

While utilities and technology giants work to generate more electricity and expand grid capacity, Empower is focused on a different pain point: How to deliver all that power very fast and efficiently once it’s inches away from the chip.

The Series D round, led by Fidelity Research and Management Company, was joined by several other investment firms with a track record of betting on under-the-radar components used in AI infrastructure, including Maverick Silicon and Atreides Management. Another notable name is CapitalG, the growth-stage investment arm of Google parent Alphabet.

All of the leading players in power electronics have ventured into the AI landscape at this point. But the Santa Clara, Calif.-based startup aims to differentiate itself with integrated voltage regulators (IVRs). These ICs integrate an entire voltage regulator within a single ultra-thin package, replacing traditional board-level designs. Empower uses FinFET-based power transistors to run at very high bandwidths and respond to the fast-changing load conditions prevalent in AI workloads, thus saving power.

The financing comes around a year after the startup revealed its latest family of IVRs dubbed Crescendo. The technology can be placed directly underneath the SoC on the opposite side of the PCB.

This vertical placement allows them to feed more than 3,000 A directly into the load, bypassing the longer lateral paths of a traditional power delivery network (PDN). Doing so can reduce power losses in the PDN by as much as 20%. It also improves transient response, which is critical because AI chips tend to fluctuate rapidly between idle and peak power states.

In the short term, the cash infusion will help support mass production of Empower’s Crescendo platform. Long term, it will fund future development plans, including next-gen AI power innovations, according to the firm.

“The syndicate we now have backing Empower underscores the strength of our technology lead, market opportunity, and depth of customer adoption,” said Tim Phillips, Empower’s founder and chief executive.

The Shift from Board-Level to Chip-Level Voltage Regulation

Power management is emerging as a huge challenge in the era of big AI chips such as NVIDIA’s Blackwell GPU, which burns through 1,200 W, and the Blackwell Ultra that pushes the power envelope to 1,400 W.

To manage the immense power demand, the chips are surrounded as close as possible by voltage regulator modules (VRMs), often flanking the north and south or east and west edges of the chip. Inductors placed on the PCB or stacked directly on top of the VRM are used to smooth out its output and filter out noise. To stay ahead of the sudden power spikes — a regular occurrence with AI — and prevent voltage droop during these sudden load transients, decoupling capacitors are placed in large numbers under the PCB.

However, as the supply voltages of these chips continue to rise and current demands escalate, lateral power delivery is under pressure. The challenge is figuring out how to place enough power electronics in the PCB to deliver currents often more than 2,000 A to the SoC. At the same time, engineers must reduce resistive losses (I²R) due to high PDN impedance before burning everything apart. The other question is how to reduce inductance in the PDN without using hundreds of decoupling capacitors, which can add to system complexity.

Empower said its speed is a better solution to many of these issues. The IVR at the heart of the Crescendo is based on the same FinFET technology at the heart of the most advanced logic chips today. By using CMOS instead of the BCD technology that’s standard in most power-management ICs, Crescendo enables very fast transient response — 20X faster than traditional solutions — against the steep power steps in AI and HPC compute.

By being able to adjust its output voltage very fast, Empower said Crescendo can eliminate most of the inductors on top of the PCB and the large number of capacitors under the PCB to smooth out power entering the load.

Today, AI chips rarely run at their minimum operating voltage due to the risks posed by voltage droop, which occurs when the current racing into the processor abruptly changes due to workload fluctuations. This can lead to a drop in the supply voltage to the SoC, which can cause performance degradation.

By responding instantly to sudden changes in load current, Empower claimed Crescendo can save power inside the processor by allowing it to reduce voltage droop and operate closer to its minimum core voltage.

By removing all of the usual passive components, the startup said it can relocate directly under the SoC where the capacitors used to reside. This reduces the distance that the current travels to the load and the power losses that can crop up when pushing power laterally through the copper wires in the PCB. Heat can also be alleviated. The passives that aren’t able to be removed can be replaced with the company’s high-frequency magnetics embedded in the IVR and its wide-bandwidth silicon capacitors placed inside the IVR, in the SoC, or on the PCB.

Crescendo is modular and scalable. Empower said it can integrate up to 50 voltage regulators into a multiphase DC-DC converter that can step down a 3.3-V input to between 0.3 and 1.8 V (depending on the SoC’s core voltage) while delivering more than 3,000 A. Driven by its 2X lower voltage-droop response, Empower said Crescendo delivers a 15% reduction in XPU power and higher processor utilization for a typical AI workload.

Crescendo will ultimately compete with more traditional VRMs from the likes of Infineon Technologies, which recently joined forces with Delta Electronics to enable vertical power delivery (VPD).

Commercial Buy-in for Voltage Regulator ICs

Though relatively new to the power electronics market, Empower said it’s currently working on several commercial deployments of the Crescendo platform, which the startup is preparing for mass production later this year.

“As power demand in data centers continues to rise, a new technology is required to enable the next generation of AI performance and Empower is setting the standard,” said Andrew Homan, managing partner at Maverick Silicon.

One of its latest collaborations is with Marvell Technology. Marvell builds custom AI accelerator chips for others, and it recently announced plans to bring Empower’s pre-validated IVR power solutions to these custom XPU customers. “Placing integrated voltage regulators under, near, or inside the package delivers greater performance and greater efficiency,” said Will Chu, SVP and GM of custom cloud solutions at Marvell.

Ferric, one of the other startups developing voltage regulator ICs for AI power delivery, has also partnered with Marvell.