Using Full Wave 3D Simulation to Evaluate Buck SMPS EMC Emissions

This paper demonstrates the use of 3D electromagnetic (EMC) modeling to simulate the conducted emissions of a switched-mode power supply (SMPS). The simulations are performed using CST Studio Suite from Dassault Systemes and measurements of a fully functional SMPS converter are performed according to CISPR25 (an automotive test specification). The simulations are compared to the measurements and demonstrate a reasonable level of correlation. Several SMPS design modifications are evaluated using simulation and compared to measurements. The benefits of using simulation early in the development process to help prevent EMC failures is highlighted.