Inductors and Magnetic Beads

1. Inductors is the energy storage element, and magnetic bead is the energy conversion (consumption) device.

2, Inductors is mainly used for power filter loop, magnetic beads are mainly used for signal loop, for EMC countermeasures; 

3, Magnetic beads are mainly used to suppress electromagnetic radiation interference, and inductance for this aspect is focused on suppressing conductive interference, both can be used to deal with EMC, EMI problems; There are two approaches of EMI, namely radiation and conduction. Different approaches adopt different suppression methods, the former using magnetic beads, the latter using inductance; 

4, Magnetic beads are used to absorb ultra-high frequency signals, like some RF circuits, PLL, oscillation circuit, including ultra-high frequency memory circuit (DDRSDRAM, RAMBUS, etc.) are needed in the power input part of the magnetic beads, and inductance is a kind of energy storage element, used in LC oscillation circuit, low frequency filter circuit, its application frequency range rarely exceeds 50MHZ; 

5, inductance is generally used for circuit matching and signal quality control, general connection and power supply connection. Use magnetic beads where analog and digital are combined. Magnetic beads are also used for signal lines. 

The size of the bead (or rather the characteristic curve of the bead) depends on the frequency of the interference wave that the bead is required to absorb. Magnetic beads are high frequency resistance, low resistance to DC, high resistance to high frequency. Because the unit of a magnetic bead is nominal in terms of its generated impedance at a certain frequency, the unit of impedance is also ohms. A frequency and impedance characteristic plot is usually attached to the magnetic bead datasheet. The Impedance of the bead is 600 ohm at 100MHz. For example, 2012B601, the impedance of the bead is 600 ohm at 100MHz.