What are the special properties of EMC chip beads

    EMC chip beads are used to suppress EMI in electronic circuits. There are two main applications: 1. The most common use is for power lines. 2. Used for signal lines like audio, video lines, etc. How to choose suitable magnetic beads from tens of thousands of EMC magnetic beads with different characteristics for your own system design according to the actual application? First of all, we must know the operating frequency of the switching power supply. Usually most switching power supplies work at hundreds of KHz, and a few can work at several MHz. This frequency is basically in the frequency range of conducted radiation. For the radiation frequency starting at 30MHz, it belongs to the low frequency range. Generally speaking, the radiated EMI noise generated by the power supply is usually in the range of less than 100MHz-300MHz. Therefore, when choosing magnetic beads, use low-frequency magnetic beads with a peak frequency less than 300MHz.

    Secondly, it is necessary to know the operating current of the power supply. For the magnetic beads that are placed on the switch or non-DC signal, it is usually necessary to convert the effective value of the AC signal to select the rated current of the magnetic beads. Regarding the size of the magnetic beads used for the power cord, as we mentioned earlier, in the case of meeting the design requirements of the layout space, it is necessary to use large-sized beads as much as possible.