Author : Jizheng Qiu
Publisher :
ISBN 13 :
Total Pages : 392 pages
Book Rating : 4.:/5 (843 download)
Book Synopsis Thin-film Inductors for Multi-megaherts Power Conversion by : Jizheng Qiu
Download or read book Thin-film Inductors for Multi-megaherts Power Conversion written by Jizheng Qiu and published by . This book was released on 2013 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Magnetic components are required in most efficient dc-dc power converters. Power converters using a switching frequency in the multi-megahertz range (1-100 MHz) have been developed for miniaturization. However, the high switching frequency involves challenges in circuit and magnetic component design. Air-core inductors are used in most high-frequency converters. Howerver, magnetic-core inductors are sitll attractive because they provide the opportunity to miniaturize the inductor size while maintaining low loss, whereas air-core inductors require substantial thickness to obtain good performance. Advanced magnetic materials are required for magnetic-core inductors to operate efficiently in the high frequency range. Miniaturized thin-film power inductors for high-frequency dc-dc power conversion are investigated. Co-Zr-O, an advanced nanogranular thin-film magnetic material, exhibits high saturation flux density (>1 T), high resistivity, and low hysteresis loss. Low-profile thin-film inductors with this advanced magnetic material are expected to demonstrate high power density and high efficiency, and be suitable for multi-megahertz power applications. A high-frequency resistivity measurement method is developed to better predict the loss in multilayer thin-film magnetic material for inductor design. Two types of microfabricated inductors are investigated: a "pot-cor" inductor which has two magnetic layers surrounding the winding layer in the middle, and a toroidal inductor which has two conductor layers surrounding the magnetic layer in the middle. A new category of anisotropic thin-film magnetic material, named radially anisotropic magnetic material, with a radial easy axis and circumferential hard axis, is introduced and developed to be used in thin-film toroidal inductors. Loss models, inductor design methods, co-optimization of magnetics with circuits, fabrication, and measurements are studied in this thesis."