What are the functions of magnetic beads

What are the functions of magnetic beads

Magnetic beads are used to suppress high-frequency noise and spike interference on signal lines and power lines, and have the ability to absorb electrostatic pulses. Magnetic beads are used to absorb ultra-high frequency signals, such as some RF circuits, PLLs, oscillation circuits, and ultra-high frequency memory circuits that need to add magnetic beads to the power input part, and the inductor is an energy storage element used in LC oscillation Circuits, medium and low frequency filter circuits, etc., whose application frequency range rarely exceeds 50MHZ. Magnetic beads have very high resistivity and permeability, which is equivalent to a series connection of resistance and inductance, but the resistance value and inductance value change with frequency.

The function of the magnetic beads is mainly to eliminate the RF noise existing in the transmission line structure. The RF energy is the AC sine wave component superimposed on the DC transmission level, and the DC component is the useful signal required. To eliminate these unwanted signal energy, chip magnetic beads are used to play the role of high-frequency resistance.

Magnetic beads have very high resistivity and permeability, which is equivalent to a 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 shows resistance at high frequencies, so it can maintain a higher impedance in a relatively wide frequency range, thereby improving the FM filtering effect.

As a power filter, an inductor can be used. The circuit symbol of a magnetic bead is an inductance, but it can be seen from the model that the magnetic bead is used. In terms of circuit function, the principle of the magnetic beads and the inductor are the same, but the frequency characteristics are different.

The DC component is a useful signal that is needed, while the radio frequency RF energy is useless electromagnetic interference that is transmitted and radiated along the line. To eliminate these unwanted signal energy, chip magnetic beads are used to play the role of high-frequency resistance. The device allows DC signals to pass, while filtering out AC signals. Usually high-frequency signals are above 30MHz, however, low-frequency signals are also affected by chip magnetic beads. Magnetic beads have high resistivity and permeability, which is equivalent to a series connection of resistance and inductance. As long as the wire passes through it in the circuit. The high-frequency current is dissipated in the form of heat. The equivalent circuit is an inductance and a resistor in series, and the values of the two components are proportional to the length of the magnetic beads. Some magnetic beads have multiple holes, through which wires can increase the impedance of the component. Ferrite beads can be used not only to filter high-frequency noise in power circuits, but also to be widely used in other circuits.