Meijia Magnetoelectronics
20+Year Ferrite Core Material Professional Manufacturer
0769 - 8961 5621
News Catalogue
Latest News
Application Principle of Clamp Type Ferrite Ring Core

Category : Knowledge sharing     Date : 05/05/2023
Clamp type magnetic rings are commonly used for EMI filtering, suppressing interference on power and signal lines, and also have the ability to absorb electrostatic pulses.
The phenomenon of electromagnetic waves interfering with electronic components is called EMI (Electromagnetic Interference). For example, the common "snowflakes" on TV fluorescent screens indicate that the received signal is interfered by EMI. At this time, the magnetic ring can play a role in absorbing interference, which is characterized by its impedance characteristics. In the low frequency band, it presents a very low inductive impedance value, which does not affect the transmission of useful signals on data or signal lines. However, starting from around 10MHz in the high frequency band, the impedance increases, and its inductive impedance component remains very small, while the resistive component rapidly increases, Absorb and dissipate high-frequency EMI interference energy in the form of thermal energy. Generally, resistance values are measured at two frequency points of 25MHz and 100MHz to calibrate the absorption characteristics of the magnetic ring towards EMI.
The advantages of clamp type magnetic rings are as follows:,
1. It can be directly installed on power and signal lines, and can be repeatedly wound several times to increase interference absorption energy;
2. EMI magnetic ring with mounting clip, suitable for compensating anti-interference suppression;
3. Can be conveniently clamped on power and signal lines;
4. Flexible and reusable installation;
5. Equipped with card type fixation, which does not affect the overall image of the equipment

Compared to the two half clamp type magnetic ring, the general magnetic ring is a common anti-interference component in electronic circuits, which has a good suppression effect on high-frequency noise. It is used for electronic devices in daily life, such as display signal cables, USB connection cables, and plastic lumped integrated magnetic rings on data lines. The magnetic ring has different impedance characteristics at different frequencies, and the impedance is generally very small at low frequencies. When the signal frequency increases, the impedance of the magnetic ring increases sharply. The higher the signal frequency, the easier it is to radiate out. Generally, signal lines do not have a shielding layer. At this point, these signal lines become good antennas to receive various chaotic high-frequency signals in the surrounding environment. These signals are superimposed on the originally transmitted signals, and even change the originally transmitted useful signals. Under the action of the magnetic ring, normal useful signals pass through well and high-frequency interference signals can be effectively suppressed. It can be used in conjunction with coil winding to form a choke coil, which is lower in cost compared to the two half clamp magnetic buckle and has no significant difference in performance.