As data centers consume more energy to keep up with growing digital demands, engineers at the University of California, San Diego have introduced a new chip design that can more efficiently power graphics processing units (GPUs). This innovation focuses on a critical function in electronics: converting high voltages to the lower levels needed by computing hardware. In laboratory tests, the prototype chip was able to perform this type of voltage conversion with high efficiency under conditions similar to modern data centers.
The survey results are nature communicationssuggesting the potential for smaller and more energy-efficient systems in advanced computing environments.
Rethinking DC-DC converters for modern electronics
At the heart of the new design is an improved version of a widely used component known as a DC-DC step-down converter. These converters are found in almost every electronic device and act as a critical link between power supplies and sensitive circuits. Their job is to take a high input voltage and reduce it to the exact level required for safe operation.
In data centers, power is often distributed at 48 volts, but GPU processors typically require much lower voltages, typically 1 to 5 volts. As computing systems become more powerful and compact, managing this large voltage drop effectively becomes increasingly difficult.
Limitations of conventional power conversion technology
Traditional buck converters often have difficulty handling large differences between input and output voltages. As the gap increases, efficiency decreases and it becomes difficult to supply sufficient current. Most existing designs rely on magnetic components such as inductors. Although these components have been improved over the years, they are approaching their practical limits and are becoming difficult to improve further.
“Inductive converter designs have gotten so good that there is little room for improvements to meet future needs,” said study lead author Patrick Mercier, a professor in the Department of Electrical and Computer Engineering at the UC San Diego Jacobs School of Engineering.
Consideration of piezoelectric resonators as alternatives
To overcome these limitations, Mercier and his team include lead author Jaeyoung Koh, a Ph.D. in electrical and computer engineering; student at the University of California, San Diego, researched a different approach using piezoelectric resonators. These small devices store and transfer energy through mechanical vibrations rather than magnetic fields.
Converters based on piezoelectric components have several advantages. These could be smaller, more energy-dense, more efficient, and easier to manufacture at scale. “They have a lot of room to grow and have the potential to outperform any company in history,” Mercier said.
However, previous versions of piezoelectric converters had difficulty maintaining efficiency and providing sufficient power when handling large voltage differences.
Hybrid design achieves high efficiency and high output
To overcome these problems, researchers created a hybrid converter that combines a piezoelectric resonator with small commercially available capacitors arranged in a carefully designed configuration. This setting allows the system to handle larger voltage conversions more effectively.
The team incorporated this design into a prototype chip and tested its performance. The device successfully converted 48 volts to 4.8 volts, a level commonly required in data centers, with a peak efficiency of 96.2 percent. It also delivered approximately four times more output current than previous piezoelectric-based designs.
This hybrid approach has several advantages. It creates multiple paths for energy to move through the system, reducing wasted power and reducing strain on the resonator. These improvements increase both efficiency and power delivery with only a small increase in chip size.
Challenges and next steps for real-world use
Although this technology shows great promise, it is still in the early stages of development. Researchers see this as an important step toward overcoming the limitations of current power conversion systems. Future efforts will focus on improving materials, improving circuit design, and developing better packaging methods.
One challenge is that piezoelectric resonators physically vibrate. This means that the piezoelectric resonator cannot be attached to a circuit board using standard soldering techniques. Incorporating these into electronic systems will require new integration strategies, Mercier explained.
“Piezoelectric-based converters are not yet ready to replace existing power converter technologies,” Mercier added. “However, they point to a path to improvement. For this technology to be usable for data center applications, continued improvements are needed in multiple areas, including materials, circuitry, and packaging.”
This project was supported in part by the Power Management Integration Center (PMIC), an Industry-University Collaborative Research Center (IUCRC) funded by the National Science Foundation (award number 2052809).
