A Ferrite Core without Grounding as a noise suppression


Compared to other noise suppression devices that require circuit connections (such as capacitors), a Ferrite Core does not need Grounding. This can be an advantage, as grounding a noise suppression device runs the risk of placing part of that noise back into the circuit and causing the circuit ground to be unstable.

When a current-carrying cable is passed through a ferrite core, magnetic fields are generated by the current and are reduced by the ferrite core because of its “magnetic flux” absorption capability

The magnetic field of ‘data’ current will flow through the inner regions (near the core) of the ferrite, while the magnetic field of ‘noise’ current will flow through the outer area. Due to the longer flow path, magnetic loss is converted into heat and dissipated, thus preventing noise emission. This allows noise suppression without the need for grounding.

The magnetic flux of the noise current decreases inversely proportionally to the impedance of the ferrite core. Higher impedance will more strongly reduce noise current.