Inductive components and appropriate magnetic materials for filters in SMPS-designs

Today filter-chokes (differential-and common-mode) as well as output-chokes face rising power-densities as a result of very high switching frequencies. A variety of different soft-magnetic materials are presented for usage in this components. Ferrites and special solutions e.g. amorphous cut cores, both with discrete air gap, are compared to the powder-cores with their distributed air gap. All this leads to special design opportunities offering many ways to optimize the inductor. Finally an outlook on future developments based on the upcoming new requirements will be given.