Ferrite core

One of the cores widely used in transformers and choke coils of switching power supplies. The most commonly used type of ferrite is spinel ferrite, which is represented by the molecular formula MO·Fe2O3 (where M is a divalent metal). Spinel ferrite cores are manufactured by placing metal oxide powder into a mold, compacting it, and then firing it. To increase the saturation magnetic flux density, spinel ferrite is often made by mixing multiple metal materials, and is therefore called composite ferrite.

Ferrite cores have the advantage of low iron loss even when there are large changes in magnetic flux density in high-frequency regions, making them suitable for output transformers and transformers with large current fluctuations. On the other hand, they have the disadvantage of lower saturation magnetic flux density compared to metal cores.

In addition, the core attached to the DC cable as an EMI countermeasure (noise suppression) for AC adapters is also called a ferrite core.