A filter is a device used to eliminate interference noise, filtering the input or output to obtain pure direct current. A circuit that effectively filters a frequency point of a specific frequency or a frequency other than the frequency point is a filter, and its function is to obtain a specific frequency or eliminate a specific frequency. The following electronic components procurement network Hao Qi Core Technology mainly analyzes the function and precautions of the filter for your reference.

Filter action:

(1) Separate the useful signal from the noise to improve the anti-interference and signal-to-noise ratio of the signal;

(2) Filter out uninteresting frequency components to improve analysis accuracy;

(3) Separate a single frequency component from the complex frequency component.

Precautions for filter use Although the on-board filter is not ideal for high-frequency filtering, if it is applied properly, it can meet the electromagnetic compatibility requirements of most civilian products. Pay attention to the following when using:

If you decide to use an on-board filter, be careful to leave a "clean ground" at the cable port when routing, where the filter and connector are installed. Through the previous discussion, it can be seen that the interference on the signal ground line is very serious. If the filter capacitor of the cable is directly connected to this ground, it will cause serious common mode radiation problems. In order to obtain a better filtering effect, a clean ground must be prepared. It can only be connected to the signal ground at one point. This flow point is called a "bridge", and all signal lines pass through the bridge to reduce the signal loop area.

Side-by-side setup: All wires in the same set of cables have their unfiltered parts together and their filtered parts together. Otherwise, the filtered portion of one conductor will recontaminate the filtered portion of the other conductor9 and the overall filtering of the cable will fail.

Proximity to cables: The distance between the wires of the filter and the panel should be kept as short as possible. If necessary, use a metal plate to shield it to isolate near-field interference.

Connect with the chassis: The clean ground where the filter is installed should be connected to the metal chassis reliably. If the chassis is not metal, a larger metal plate should be set under the circuit board as the filter ground. A clean bond to the metal chassis should ensure low RF impedance. If necessary, an electromagnetic sealing gasket can be used to overlap to increase the overlap area and reduce RF impedance.

Short ground wire: Considering the inductive effect of the pins, its importance has been discussed earlier, and special attention should be paid to the local wiring of the filter and the connection structure of the circuit board and the chassis (metal plate).

Application fields of filters: communication industry; semiconductor industry; petrochemical industry; chemical fiber industry; steel/intermediate frequency heating industry; automobile manufacturing; DC motor harmonic control; the use of automated production lines and precision equipment; hospital systems; processing; image processing; smart TV; radar; music field; system identification or system modeling; smartphone. Shenzhen Hao Qi Core Technology operates a wide variety of filters and brands. If you want to buy filters in the near future, please contact online customer service in time.