The function of the magnetic beads is mainly to eliminate the RF noise of the circuit element symbols of the magnetic beads existing in the transmission line structure (circuit). RF energy is an AC sine wave component superimposed on the DC transmission level, and the DC component is a useful signal required. To eliminate these unwanted signal energy, use chip beads to act as high-frequency resistors (attenuators).
Magnetic beads have high resistivity and permeability, which is equivalent to the series connection of resistance and inductance, but the resistance value and inductance value change with frequency. It has better high-frequency filtering characteristics than ordinary inductors, and appears resistive at high frequencies, so it can maintain a high impedance over a relatively wide frequency range, thereby improving the frequency-modulation filtering effect.
As a power supply filter, an inductor can be used. The circuit symbol of the magnetic bead is the inductance, but it can be seen on the model that the magnetic bead is used. In terms of circuit function, magnetic beads and inductors have the same principle, but the frequency characteristics are different.
The DC component is the desired useful signal, while the RF RF energy is useless electromagnetic interference that is transmitted along the line and radiated (EMI). To eliminate these unwanted signal energy, use chip beads to act as high-frequency resistors (attenuators). This device allows DC signals to pass and filters out AC signals. High-frequency signals are usually above 30MHz. However, low-frequency signals are also affected by chip beads. Magnetic beads have high resistivity and permeability, which is equivalent to the series connection of resistance and inductance. As long as the wire goes through it in the circuit. The high-frequency current is radiated in the form of heat. The equivalent circuit is an inductor and a resistor in series. The value of both components is proportional to the length of the magnetic bead. Some magnetic beads have multiple holes, and the resistance of the component can be increased by passing through the wire (the square of the number of times the magnetic beads are passed). Ferrite beads can not only be used to filter high-frequency noise in power circuits (for DC and AC output), but also widely used in other circuits.
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