Ferrite Bead Selection for DC/DC Converter Filtering

This guide discusses the selection of ferrite beads for filtering in DC/DC converters, focusing on efficient EMC and power converter design. It outlines the challenges faced in designing a 100W buck-boost DC/DC converter with a minimum efficiency of 95% while ensuring compliance with EMC standards for both conducted and radiated emissions. The document details various design approaches, including the use of different PCB layouts and the selection of components such as MOSFETs and inductors. It also presents simulation results from LTSPICE for different filter designs, including T-filters and common mode chokes, to mitigate emissions. The guide emphasizes the importance of component selection and layout in achieving optimal performance and compliance. Additionally, it includes measurements for conducted and radiated emissions across multiple designs, providing insights into the effectiveness of the implemented filtering solutions.