A Scientific Approach to EMI Reduction

The increasingly larger scale of integration in electronic systems has demanded a corre-sponding increase in the density of the power supplies of these systems. To some extent, this demand has been met by resorting to higher switching frequency power converters (-1 MHz). One of the major problems with high frequency switching converters is the gen-eration of radio frequency signals which may interfere with communication broadcasts. The amount of this electromagnetic interference (EMI) which a product may generate is subject to governmental regulations throughout much of the world. The regulatory standards can generally be met with the addition of an EMI filter on the line side of the power supply. EMI filters may be quite large due to the large storage elements needed to filter the power line. The application of EMI filters is generally quite unscientific and often results in costly it-erations and suboptimal results. Power supply and EMI filter designs might be significantly improved by investigation of some of the issues associated with these filters, development of some useful instrumentation procedures, and the application of some methodology an