Magnetic rob have different impedance characteristics at different frequencies. Generally, the impedance is very small at low frequencies, and the impedance rises sharply at high frequencies. The higher the signal frequency, the easier it is for the magnetic field to radiate out. Generally, signal lines are not shielded. For example, the CAN bus I use now. These signal lines become antennas. This antenna continuously receives surrounding high-frequency signals. Superposition changes the actual signal to be transmitted. The magnetic ring can pass useful signals well while suppressing high-frequency interference signals.
In the high frequency range, the inductive reactance remains small, while the impedance is large, so that when the energy of the high-frequency signal passes through the magnetic material, it is converted into heat and emitted, which prevents the passage of the high-frequency signal and suppresses the interference of the high-frequency signal. . Usually the suppression frequency range is related to the ferrite suppression element. Generally, the higher the magnetic permeability, the lower the suppression frequency. The larger the volume of the ferrite, the better the suppression effect. When the volume is constant, the longer and thinner are longer than the shorter and thicker ones. The suppression effect is good, the smaller the internal strength, the better the suppression effect.
When suppressing common mode signal interference, you can pass the signal or power line through the flat magnetic ring at the same time. In order to increase the effect, you can make a few symmetrical turns on the magnetic ring to increase the inductance and enhance the absorption effect of the common mode signal. The bad signal has no effect.
Huizhou Mingda Precise Electronics Co., Ltd. have a manufacturer specializing in the production of EMI anti-interference magnetic rings. We have engineers with 20 years of TDK R&D and design experience. We can customize magnetic rings with special performance and size according to the different needs of customers for EMI anti-interference magnetic rings. product.
Post time: Jul-21-2021