Electric and magnetic circuit interactions in switching converters

摘要

In switching converters very often the magnetic circuit part can seriously affect the converter electrical circuit performance, such as frequency response, for example. Conversely, the electrical circuit may impose undesirable waveforms upon the magnetic circuit and make it inefficient. The causes of these magnetic and electric circuit interactions in sWitching converters are uncovered. The proposed solutions are verified on a 220W, five output off-line switching power supply for high resolution color monitors meeting very stringent military specifications. This design case study also addresses a number of important practical issues such as: optimum design of the six-winding coupled-inductor structure, EMI design for low noise, and start-up transient problems as well as several other practical problems encountered during the manufacturing phase.