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dc.contributor.authorQu, Songen_US
dc.date.accessioned2011-08-06T14:49:35Z
dc.date.available2011-08-06T14:49:35Z
dc.date.issued2004-04-09en_US
dc.identifier.otheretd-022199-114952en_US
dc.identifier.urihttp://hdl.handle.net/10919/9788
dc.description.abstractElectromagnetic Interference (EMI) problems in switching power supplies have been traditionally treated with cut-and-try approaches. In recent years, advancement has been made to better understand the problems and minimize the cut-and-try portion of the design process. However, there are still phenomena difficult to explain in many practical design situations. Often, the problems may be solved by luck but many puzzles remain unsolved. If not fully understood, these puzzles are very likely to come back to haunt the designers. According to the conventional theory, there are two modes of noise: the Differential-Mode (DM) noise and the Common-Mode (CM) noise. Recently, a new noise-coupling mode called Non-Intrinsic Differential-Mode (NIDM) noise was uncovered accidentally in the process of explaining certain EMI filter action [1]. This phenomenon has never been thoroughly studied. The focus of the present thesis is to investigate the NIDM phenomenon and its implications to practical EMI filter design issues. The generation mechanism and basic characteristics of this phenomenon will be briefly reviewed, which is crucial to the understanding of the remaining parts of the research. Two essential diagnostic tools are introduced. One is the DM/CM noise separator and the other is the zero-span mode operation of a spectrum analyzer. The results of the investigation will be presented. The results will be presented using practical examples, which tie the phenomenon to filter design issues. In some examples, explanations are given to dispel the puzzles commonly encountered in the practice. A filter design procedure is suggested for off-line power supplies. This procedure incorporates the NIDM phenomenon into an existing design procedure. Only first-order and second-order filter topologies are included in the discussion.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.relation.haspartFRONTMATTER.PDFen_US
dc.relation.haspartQUBODYMATTER.PDFen_US
dc.rightsI hereby grant to Virginia Tech or its agents the right to archive and to make available my thesis or dissertation in whole or in part in the University Libraries in all forms of media, now or hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertation.en_US
dc.subjectNIDMen_US
dc.subjectEMIen_US
dc.subjectFilteren_US
dc.subjectSwitching Power Supplyen_US
dc.titleNon-Intrinsic Differential-Mode Noise in Switching Power Supplies and Its Implications to EMI Filter Designen_US
dc.typeThesisen_US
dc.contributor.departmentElectrical and Computer Engineeringen_US
dc.description.degreeMSen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairChen, Dan Y.en_US
dc.contributor.committeememberBorojevich, Dushanen_US
dc.contributor.committeememberHuang, Alex Q.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-022199-114952en_US
dc.date.sdate1999-02-21en_US
dc.date.rdate2000-02-23
dc.date.adate1999-02-23en_US


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