Ferrite materials for switched mode power supplies

The major growth in the production of ferrite cores in recent years is due to a considerable increase in the use of switched-mode power supplies. After summarizing the main types of cores most utilised for this application, the author sets out the main characteristics generally required of ferrite materials. The main properties of the standard materials, the new materials tailored for the present applications, and the future materials usable at frequencies up to 250 kHz, are then given and discussed.