EMC CHARACTERIZATION OF SMPS DEVICES - CIRCUIT AND RADIATED EMISSIONSMODEL

Since the efficiency of switched mode power supplies (SMPS) is much hi gher than that of linear power supplies, this type of supply has gaine d favor among designers and manufacturers. Switching frequencies exten d from tens to hundreds of kilohertz with the result that radiation fr om circuits carrying switched current is becoming more of a problem. T his paper addresses the modeling of the converter section of an SMPS i n order to calculate the current distribution and the radiated electro magnetic field, The inhomogeneities in the circuit are treated by equi valent electrical parameters and a technique is introduced to take int o account the fictitious effects on radiation due to the electrostatic terms in the dipole equations. The global approach is validated by co mparison of the computed results with those measured for a simple and clearly arranged SMPS experimental setup.