Analysis and Suppression of Power Supplies Switching Noise

The report contains the results of research that was accomplished in Kiev Polytechnic Institute laboratory of Power Supplies and Electromagnetic Compatibility (EMC) of Electronics. One of the main problems in EMC of radioelectronic devices is that usually a power supply is designed separately from another company (or bought). It gives the result that ”modest toiler” which interconnects all circuits of device mentioned becomes the serious reason for electromagnetic noncompatibility of functional parts of the device. And if the power supply is of switching type one, it becomes the additional source of electromagnetic interference (EMI). The purpose of this report is to propose the method and software (algorithms and programs) that provide a designer with opportunity to meet demands of EMC at the stage of switch mode power supply (SMPS) design. The method and programs are worked out for a personal computer. As an example the analysis for a half-bridge inverter with auxiliary noise suppressing circuits has been done. Also advantages of resonant type inverters and new techniques of noise suppressing filters are shown.