Hello everyone, I am Shunhai Science and Technology Xiaobian. What are the differences between SMD inductors and SMD magnetic beads? The following contents are compiled by Shunhai Science and Technology, and relevant contents are for reference.
How to treat the model of SMD magnetic bead inductor. The inductance of SMD beads mainly depends on the design requirements. Magnetic beads are used to suppress high-frequency noise and peak interference on signal lines and power lines. They also have the ability to absorb electrostatic pulses and can be used to absorb ultra-high frequency signals.
1. SMD magnetic beads can be divided into four types: ordinary magnetic beads, high-current magnetic beads, peak magnetic beads and high-frequency magnetic beads
Ordinary magnetic beads: EMI suppression performance in a wide frequency range, good weldability, suitable for automatic installation of SMT equipment.
High current magnetic beads: high rated current, allowing high current of 6A, high impedance value and EMI suppression effect in wide frequency range, suitable for flow welding and reflow welding.
Peak magnetic beads: in a certain frequency region, the impedance value rises sharply, and a high attenuation effect is obtained in a specific frequency region, which has no effect on the signal. 4) High-frequency magnetic beads have excellent EMI performance at high frequency (above 1 GHz).
Second, the difference between SMD inductor and SMD magnetic bead
(1) the function of flake magnetic beads is mainly to eliminate RF noise in transmission line structure (PCB circuit). RF energy is AC sine wave component superimposed on DC transmission level, DC component is needed useful signal, while RF energy is useless electromagnetic interference transmission and radiation (EMI). In order to eliminate these unnecessary signal nergies, chip magnetic beads are used as high frequency resistors (attenuators), which allow DC signals to pass through and filter AC signals. Usually, the high frequency signal exceeds 30 MHz, but the low frequency signal is also affected by the chip magnetic beads.
(2) The flaky magnetic beads are made of soft magnetic ferrite material, which constitutes a monolithic structure with high volume resistivity. The eddy current loss is inversely proportional to the resistivity of ferrite material. Eddy current loss is proportional to the square of signal frequency.
(3) Advantages of using flake magnetic beads: miniaturization and light weight. RF noise has high impedance in the frequency range, which eliminates electromagnetic interference in transmission lines. Close the magnetic circuit structure to better eliminate the winding of signals. Good magnetic shielding structure. Reduce DC resistance and avoid excessive attenuation of useful signals.
