To fully leverage the performance of ferrite magnetic cores, the following precautions are crucial:

The effect of ferrite cores (beads) is related to circuit impedance: the lower the circuit's impedance, the better the filtering effect of the ferrite cores (beads). Therefore, in the product manuals of general ferrite materials, the insertion loss of the ferrite material is not provided, but the impedance is given. The higher the impedance of the ferrite material, the better the filtering effect.

B) Influence of Current: When a higher current flows through the wire passing through the ferrite, the low-frequency insertion loss of the filter decreases, while the high-frequency insertion loss changes minimally. To avoid this, when using on the power line, both the power line and the return line can be passed through the ferrite simultaneously.

C) Selection of Ferrite Materials: Different ferrite materials with varying magnetic permeability are chosen based on the frequency of interference to be suppressed. The higher the magnetic permeability of the ferrite material, the greater the impedance at low frequencies and the smaller the impedance at high frequencies.

D) Determining the Size of Ferrite Core Magnets: The larger the difference between the inner and outer diameters of the magnet, the longer the axial length and the higher the impedance. However, the inner diameter must be tightly wrapped around the wire. Therefore, to achieve greater attenuation, use a larger volume magnet while ensuring the ferrite core inner diameter is tightly wrapped around the wire.

The turns of the common-mode choke: Increasing the turns passing through the magnetic ring can increase the impedance at low frequencies; however, due to increased parasitic capacitance, the impedance at high frequencies will decrease. Blindly increasing the number of turns to enhance attenuation is a common mistake. When a wider interference frequency band needs to be suppressed, different turns can be wound on two magnetic rings.

The number of ferrite cores on the cable: Increasing the number of ferrite cores on the cable can enhance low-frequency impedance, but it will reduce high-frequency impedance. This is due to the increased parasitic capacitance.

Ferrite core ring installation location: Generally, it should be as close to the interference source as possible. For cables on a shielded enclosure, the ferrite core ring should be as close to the entrance and exit points of the enclosure cables as feasible.

When used in conjunction with capacitive filter connectors, the effect is even better: the performance of the ferrite magnetic ring depends on the circuit's impedance, with lower impedance circuits yielding a more pronounced effect. Therefore, when the original cables are fitted with capacitive filter connectors at both ends, the impedance is low, making the magnetic ring's effect more noticeable.