EMI filter of folding chained form feedthru capacitor structure

Abstract

The invention discloses an EMI filter of a folding chained form feedthru capacitor structure. The EMI filter comprises a laminated substrate, an input terminal, an output terminal and two ground terminals; the laminated substrate comprises a substrate, conductive polar plates, a ground polar plate and a metal through hole, which are laminated from bottom to top in sequence; the conductive polar plate is arranged on the surface of the substrate; one end of the conductive polar plate at the first layer is connected with the input terminal, one end of the conductive polar plate on the last layer is connected with the output terminal, and the ground polar plate is arranged on the surface of the rest substrate; both ends of the ground polar plate are connected with the two ground terminals; the metal through hole is along the lamination direction of the substrate, and the conductive polar plates are connected at heads and tails through the metal through hole, so that the conductive polar plates and the ground polar plate from a spatial folding chained form feedthru capacitor structure. The chained form structure of the EMI filter provided by the invention folds and cascades a plurality of feedthru capacitors to make full use of the parasitic effect in the structure in a limited volume to achieve excellent out-of-band rejection.

Description

technical field [0001] The invention belongs to the technical field of EMI filters, and more specifically relates to an EMI filter with a folded chain feedthrough capacitor structure. Background technique [0002] Electronic equipment brings convenience to people's production and life, but it also introduces the problem of electromagnetic interference (EMI) to other electronic equipment caused by the external emission of electromagnetic noise from the equipment, and is extremely susceptible to electromagnetic interference from the external environment; in order to prevent the equipment from being affected by external In the event of malfunction or damage due to noise interference, it is necessary to take necessary protective measures. The noise frequency of most electronic equipment is higher than the frequency of the circuit signal. Low-pass filters are often used to filter high-frequency signals and retain low-frequency operating signals. This filter is often called an EMI...

AI Technical Summary

Problems solved by technology

For capacitive chip EMI filters commonly used in electronic systems, due to the limited filtering capability of a single capacitive element, it is difficult to achieve large out-of-band attenuation on the basis of ensuring passband performance, so the performance is limited; if you want to improve For out-of-band attenuation performance, it is necessary to increase the capacitance, but too much capacitance will affect the delay characteristics of the circuit

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