The FeSi core is typically composed of 6.5% Si and 93.5% Fe. Its saturation magnetic flux density is about 1.6T; the magnetic permeability ranges from 26 to 90; the FeSi core is a veritable high-temperature material, and there is no thermal aging problem. Its core loss is lower than that of the iron powder core, and it has excellent DC bias performance. The FeSi core is mainly used in PFC circuits, new energy (solar, wind, hybrid) inverters, uninterruptible power supplies (UPS), etc.

The DC bias characteristics and power loss characteristics of the second-generation FeSi cores are equivalent to those of amorphous magnetic powder cores, and they are mainly used in home appliances, distributed photovoltaic inverters, etc. Compared with high flux magnetic powder cores, the SF type is a more economical choice; compared with sendust, its DC bias performance has obvious advantages; compared with SK series, its performance of core loss is also greatly improved.