Scientists at the University of California San Diego and CEA-LETI have developed a ground-breaking piezoelectric-based DC-DC converter that consolidates all power switches on a single chip to increase power density. This new power topology, which is an extension of the current topology, combines the advantages of piezoelectric converters with capacitive-based DC-DC converters.

The power converters the team developed are much smaller than the huge, bulky inductors currently used for this role. The devices could eventually be used for any type of DC-DC communication, in everything from smartphones, computers, server farms and even AR/VR headsets.

The results were presented in the paper “An integrated dual-side series/parallel piezoelectric resonator based on a 20-to-2.2V DC-DC converter achieving 310% loss reduction” on February 20 at ISSCC 2024 in San Francisco.

“The Dual-Side Series/Parallel Piezoelectric Resonator (DSPPR) is the first IC used for PR-based power conversion, and up to 310% loss compared to previously published and co-designed discrete designs for VCRs < 0.125 gains," the paper reports.

“This innovative approach improves efficiency, particularly at low voltage conversion ratios—an area where previous works have struggled to maintain both high efficiency and optimal utilization of piezoelectric materials,” said Patrick. said Mercier, a professor in the Department of Electrical and Computer Engineering at UC San. Diego and a senior author of the paper.

The paper explains that a hybrid DSPPR converter takes advantage of the ability of integrated circuits to offer advanced power states in a smaller area than discrete designs, and is efficient at a voltage conversion ratio (VCR) of less than 0.1. Enables device operation.

“The IC offers a unique opportunity to consolidate all power switches on a single chip, significantly reducing the PCB footprint and The accuracy of phase control increases.”

Also, adding additional capacitance-based converter stages, before and after the piezoelectric DC-DC converter, helps to improve efficiency.

“This strategic integration reduces the demand for piezoelectric materials, resulting in a more compact converter with a significantly smaller total volume. A slight increase in additional capacitors, which is less than 10 percent, is possible with the proposed topology.” pales in comparison to the substantial benefits provided by,” Pilonet said.

“The DC-DC converter, especially in the low VCR range, which was the focus of our work, has a wide range of applications in various fields, such as high-power computing servers, automotive systems, USB chargers, and battery-powered devices. devices,” said Wayne Chen Brian Liu, Ph.D. student in Mercier’s research group and lead author of the paper.