New CEA-Leti Technology Improves DC-DC Converter Efficiency and Paves the Way to Piezoelectric Converters Without Transformers

’This Type of Converter Is Now Compatible With a Much Wider Range of Applications, Such as TVs, Phones, Tablets and Electrical Tools.’-

-Grenoble, France introducing a new way of converting electrical power using piezoelectric resonators and developing a dual-bridge piezoelectric resonator converter, CEA-Leti has paved the way to isolating piezoelectric converters without transformers.

The new topology of dual-bridge isolated piezoelectric resonator converter (DB-IPRC) provides isolation using two independent piezoelectric resonators. The improved version of the DC-DC converter significantly improves efficiency, while maintaining the converter isolation principle.

The results were reported in a paper, - Switching Assisting Circuit Improving the Efficiency of DC-DC Converters Based on Piezoelectric Resonators " , presented in this summer at PCIM Europe 2024.

The paper notes that -for a 200 V to 120 V conversion, the converter shows an efficiency of 96.2 percent with the inductive assisting circuit, 94.3 percent with the piezoelectric one and 87.4 percent without any assisting circuit. The (piezoelectric resonator) assisting circuit offers a gain in efficiency over a smaller operating range than the inductance, but leads to a flatter converter."

Building on 2023 Breakthroughs

The work expands on previous results reported by CEA-Leti in the August 2023 issue of -IEEE Transactions on Power Electronics" in the article, -A New Isolated Topology of DC-DC Converter Based on Piezoelectric Resonators" . The article says that the new topology -uses the natural isolation of piezoelectric resonators to isolate the converter’s output from the input and vice-versa."

The use of piezoelectric resonators instead of inductors in power conversion -will lead to a dramatic reduction in the size of power converters," explained Ghislain Despesse, a co-author of the PCIM paper and the earlier article. -Our results make it possible to extend this type of compact conversion to isolated converters. So this type of converter is now compatible with a much wider range of applications, such as TVs, phones, tablets and electrical tools."

-For many people, piezoelectricity is associated with energy harvesting and the idea of low power," Despesse said. -But in power conversion, piezoelectrics operate at high frequencies, greater than 100kHz, with no limits in terms of input power. That makes it possible to reach power levels of several hundred watts. The range of applications is therefore very broad, with most converters having a rated power of less than 100W."

    About CEA-Leti (France)

    CEA-Leti, a technology research institute at CEA, is a global leader in miniaturization technologies enabling smart, energy-efficient and secure solutions for industry. Founded in 1967, CEA-Leti pioneers micro-& nanotechnologies, tailoring differentiating applicative solutions for global companies, SMEs and startups. CEA-Leti tackles critical challenges in healthcare, energy and digital migration. From sensors to data processing and computing solutions, CEA-Leti’s multidisciplinary teams deliver solid expertise, leveraging world-class pre-industrialization facilities. With a staff of more than 2,000 talents, a portfolio of 3,200 patents, 11,000 sq. meters of cleanroom space and a clear IP policy, the institute is based in Grenoble, France, and has offices in Silicon Valley, Brussels and Tokyo. CEA-Leti has launched 76 startups and is a member of the Carnot Institutes network. Follow us on www.leti-cea.com and @CEA_Leti.

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    CEA has a key role in transferring scientific knowledge and innovation from research to industry. This high-level technological research is carried out in particular in electronic and integrated systems, from microscale to nanoscale. It has a wide range of industrial applications in the fields of transport, health, safety and telecommunications, contributing to the creation of high-quality and competitive products.

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