Design of an inductor-less step-up ac/dc converter for 0.3 V@1 MHz vibration energy harvesting. (February 2020)

• Record Type: Journal Article
• Authors: Eguchi, Kei; Shibata, Akira; Kuwahara, Kyoka; Ishibashi, Takaaki
• Is Part Of: Energy reports. Volume 6(2020)Supplement 2
• Page Start: 159
• Page End: 165
• Publication Date: 2020-02
• Subjects: Vibration energy harvesting -- ac/dc converters -- Inductor-less converters -- Cockcroft–Walton circuit -- Charge pump -- CMOS circuits; Power resources -- Periodicals; Energy industries -- Periodicals; Power resources; Periodicals; Electronic journals; 621.04205
• DOI: 10.1016/j.egyr.2019.11.057
• Languages: English
• ISSNs: 2352-4847

Abstract

Abstract: For vibration energy harvesting, we propose an inductor-less step-up ac/dc converter in this paper. To realize the inductor-less design, the proposed ac/dc converter consists of two converter blocks: Cockcroft–Walton circuit and charge pump. Unlike existing ac/dc converters for vibration energy harvesting, the proposed ac/dc converter can achieve less electro-magnetic interference (EMI), because no magnetic component is necessary. Furthermore, owing to the Cockcroft–Walton circuit, a full-bridge circuit is not necessary to convert vibration energy. Therefore, small vibration energy, namely, as 0.3 V@1 MHz, can be converted directly to dc voltage. Through theoretical analysis and simulation program with integrated circuit emphasis (SPICE) simulation, the performance of the proposed converter with 6 × voltage gain is investigated, where the proposed converter is designed by assuming 0. 18 μ m CMOS process. The proposed converter demonstrates that about 62% power efficiency can be provided, where the output power is 30 μ W, the output voltage is about 1.6 V, and the ripple factor is 0.8%. Furthermore, the feasibility of the proposed ac/dc converter is confirmed by breadboard experiments. The inductor-less design provides us to integrate the proposed ac/dc converter into a hybrid IC chip.