Drum Core Inductors
Drum core inductors are so named as the conductor (round magnet wire) is wound directly onto the ferrite core which is shaped like a drum or spool. The wire is then connected to the core, a plastic base or metal lead frame to form the surface mount termination. Drum core inductors come in unshielded (high saturation current but potentially more EMI) and shielded constructions (lower saturation current but closed magnetic path for lower EMI). The shielded constructions use either a second ferrite core or a magnetic resin epoxy to create the magnetic shield.