CN113595378A - Filter circuit, electronic device and electric appliance - Google Patents
Filter circuit, electronic device and electric appliance Download PDFInfo
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- CN113595378A CN113595378A CN202110909554.3A CN202110909554A CN113595378A CN 113595378 A CN113595378 A CN 113595378A CN 202110909554 A CN202110909554 A CN 202110909554A CN 113595378 A CN113595378 A CN 113595378A
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M1/00—Details of apparatus for conversion
- H02M1/44—Circuits or arrangements for compensating for electromagnetic interference in converters or inverters
Abstract
The application provides a filter circuit, an electronic device and an electric appliance. The filter circuit comprises a first filter unit, a second filter unit and a third filter unit, wherein the first filter unit comprises a first common-mode inductor, a first Y capacitor and a second Y capacitor, the first end of the first Y capacitor is electrically connected with the first end of the first common-mode inductor, the first end of the second Y capacitor is electrically connected with the second end of the first common-mode inductor, and the second end of the first Y capacitor and the second end of the second Y capacitor are respectively electrically connected with a first grounding end; and the second filtering unit comprises a second common-mode inductor, a third Y capacitor and a fourth Y capacitor, wherein the first end of the third Y capacitor is electrically connected with the first end of the second common-mode inductor, the first end of the fourth Y capacitor is electrically connected with the second end of the second common-mode inductor, and the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding terminal. The scheme blocks the transmission of the common ground interference. And simultaneously, high-frequency electromagnetic interference can be suppressed.
Description
Technical Field
The application relates to the field of filter circuits, in particular to a filter circuit, an electronic device and an electric appliance.
Background
The EMI filter can effectively suppress electromagnetic interference of an external power grid and can effectively suppress electromagnetic interference signals generated by equipment so as to meet the requirements of electromagnetic compatibility standards; a common passive filter is usually composed of a common-mode inductor, an X capacitor and a Y capacitor, and is designed according to an interference frequency band and an impedance mismatch principle, and the common-mode impedance of the common-mode inductor and the bypass effect of the Y capacitor reduce conductive electromagnetic interference.
The frequency point exceeding of the electromagnetic interference of a high frequency band (about 10MHz-30MHz) is a common problem in EMC test, but the number and the number of turns of magnetic rings are often increased for suppressing the interference of the frequency band, or the number of stages of filter plates is increased, the near-field coupling between high frequency band common mode inductors is ignored, and the design cost and the efficiency are greatly increased.
A three-stage filter circuit in the prior art is shown in fig. 1, and has a disadvantage that high-frequency interference cannot be effectively suppressed, and the interference is transmitted by bypassing a common-mode inductor through a front-stage Y capacitor path (i.e., common-ground interference is generated), until the interference is detected by LISN (Line Impedance Stabilization Network), which causes filtering failure (see fig. 2); on the other hand, the design does not consider the near-field coupling M12 and M23 between the common mode inductors at high frequency. Once the interference signal exists, the high frequency interference cannot be effectively suppressed.
Disclosure of Invention
The present disclosure provides a filter circuit, an electronic device, and an electrical apparatus, so as to solve the problem that an EMI filter circuit in the prior art generates common ground interference.
In order to achieve the above object, according to one aspect of the present application, there is provided a filter circuit including: the first filtering unit comprises a first common-mode inductor, a first Y capacitor and a second Y capacitor, wherein a first end of the first Y capacitor is electrically connected with a first end of the first common-mode inductor, a first end of the second Y capacitor is electrically connected with a second end of the first common-mode inductor, and a second end of the first Y capacitor and a second end of the second Y capacitor are respectively electrically connected with a first grounding end; the second filtering unit comprises a second common-mode inductor, a third Y capacitor and a fourth Y capacitor, wherein the first end of the third Y capacitor is electrically connected with the first end of the second common-mode inductor, the first end of the fourth Y capacitor is electrically connected with the second end of the second common-mode inductor, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding end, the third end of the first common-mode inductor is electrically connected with the first end of the second common-mode inductor, and the fourth end of the first common-mode inductor is electrically connected with the second end of the second common-mode inductor.
Further, the first filtering unit further includes a first X capacitor, the second filtering unit further includes a second X capacitor, a first end of the first X capacitor is electrically connected to a first end of the first common mode inductor, a second end of the first X capacitor is electrically connected to a second end of the first common mode inductor, a first end of the first Y capacitor is located on a branch between the first end of the first X capacitor and the first end of the first common mode inductor, a first end of the second Y capacitor is connected to a branch between the second end of the first X capacitor and the second end of the first common mode inductor, a first end of the second X capacitor is electrically connected to a third end of the second common mode inductor, and a second end of the second X capacitor is electrically connected to a fourth end of the second common mode inductor.
Further, the filter circuit further includes: one or more third filtering units including a third common mode inductor, the third filtering unit being connected in series between the first filtering unit and the second filtering unit.
Further, the third filtering unit further includes a third X capacitor, a fifth Y capacitor and a sixth Y capacitor, the third end of the first common mode inductor is electrically connected to the first end of the third common mode inductor, the fourth end of the first common mode inductor is electrically connected to the second end of the third common mode inductor, the third end of the third common mode inductor is electrically connected to the first end of the second common mode inductor, the fourth end of the third common mode inductor is electrically connected to the second end of the second common mode inductor, the first end of the fifth Y capacitor is electrically connected to the third end of the first common mode inductor, the first end of the sixth Y capacitor is electrically connected to the fourth end of the first common mode inductor, the second end of the fifth Y capacitor and the second end of the sixth Y capacitor are electrically connected to a third ground terminal, the first end of the third X capacitor is connected to a common mode branch circuit between the first end of the fifth Y capacitor and the first end of the third common mode inductor, and the second end of the third X capacitor is connected to a branch circuit between the second end of the sixth Y capacitor and the second end of the third common-mode inductor.
The filter circuit further includes a first magnetic ring module, a second magnetic ring module, and a third magnetic ring module, where a first end of the first magnetic ring module is electrically connected to the second end of the first Y capacitor and the second end of the second Y capacitor, a second end of the first magnetic ring module is electrically connected to the first ground terminal, a first end of the second magnetic ring module is electrically connected to the second end of the third Y capacitor and the second end of the fourth Y capacitor, a second end of the second magnetic ring module is electrically connected to the second ground terminal, a first end of the third magnetic ring module is electrically connected to the second end of the fifth Y capacitor and the second end of the sixth Y capacitor, and a second end of the third magnetic ring module is electrically connected to the third ground terminal.
Further, the material of the first magnetic ring module, the material of the second magnetic ring module, and the material of the third magnetic ring module are one of the following: ferrite, amorphous and metallic magnetic powder cores.
The filter circuit further includes a fourth magnetic ring module, a first resistor module, and a second resistor module, where a first end of the fourth magnetic ring module is electrically connected to the second end of the first Y capacitor and the second end of the second Y capacitor, a second end of the fourth magnetic ring module is electrically connected to the first ground terminal, a first end of the first resistor module is electrically connected to the second end of the third Y capacitor and the second end of the fourth Y capacitor, a second end of the first resistor module is electrically connected to the second ground terminal, a first end of the second resistor module is electrically connected to the second end of the fifth Y capacitor and the second end of the sixth Y capacitor, and a second end of the second resistor module is electrically connected to the third ground terminal.
The filter circuit further includes a fifth magnetic loop module, a first inductor module, and a second inductor module, where a first end of the fifth magnetic loop module is electrically connected to the second end of the first Y capacitor and the second end of the second Y capacitor, a second end of the fifth magnetic loop module is electrically connected to the first ground terminal, a first end of the first inductor module is electrically connected to the second end of the third Y capacitor and the second end of the fourth Y capacitor, a second end of the first inductor module is electrically connected to the second ground terminal, a first end of the second inductor module is electrically connected to the second end of the fifth Y capacitor and the second end of the sixth Y capacitor, and a second end of the second inductor module is electrically connected to the third ground terminal.
According to another aspect of the present application, there is provided an electronic device including any one of the filter circuits.
According to an aspect of the present application, there is provided an electrical appliance including any one of the filter circuits.
By applying the technical scheme of the application, the second end of the first Y capacitor and the second end of the second Y capacitor are respectively electrically connected with the first grounding terminal, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with the second grounding terminal, namely, the Y capacitor in the first filtering unit and the Y capacitor in the second filtering unit are designed to be connected with different grounding terminals, so that the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
Drawings
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the application and, together with the description, serve to explain the application and are not intended to limit the application. In the drawings:
FIG. 1 shows a prior art three stage filter circuit diagram;
fig. 2 shows an interference transfer path in a three-stage filter circuit in the prior art;
FIG. 3 shows a two-stage filter circuit diagram according to an embodiment of the application;
FIG. 4 shows a three-stage filter circuit diagram according to an embodiment of the application;
FIG. 5 shows an overall PCB layout of the three-stage filter circuit of FIG. 4;
FIG. 6 illustrates a preferred three-stage filter circuit diagram according to an embodiment of the present application;
FIG. 7 shows another preferred three-stage filter circuit diagram according to an embodiment of the present application;
FIG. 8 shows a further preferred three-stage filter circuit diagram according to an embodiment of the present application;
FIG. 9 is a diagram showing the result of filtering using the filter circuit shown in FIG. 1;
fig. 10 shows a diagram of the filtering result of the filter circuit according to an embodiment of the present application.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise.
It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present. Also, in the specification and claims, when an element is described as being "connected" to another element, the element may be "directly connected" to the other element or "connected" to the other element through a third element.
As described in the background of the invention, in order to solve the problem that the EMI filter circuit in the prior art generates the common ground interference, embodiments of the present application provide a filter circuit, an electronic device, and an electrical appliance.
An exemplary embodiment of the present application provides a filter circuit, as shown in fig. 3, including:
a first filter unit including a first common mode inductor L1, a first Y capacitor Y1 and a second Y capacitor Y2, wherein a first end of the first Y capacitor Y1 is electrically connected to a first end of the first common mode inductor L1, a first end of the second Y capacitor Y2 is electrically connected to a second end of the first common mode inductor L1, and a second end of the first Y capacitor Y1 and a second end of the second Y capacitor Y2 are electrically connected to a first ground GND1, respectively;
a second filter unit including a second common mode inductor L2, a third Y capacitor Y3, and a fourth Y capacitor Y4, wherein a first end of the third Y capacitor Y3 is electrically connected to a first end of the second common mode inductor L2, a first end of the fourth Y capacitor Y4 is electrically connected to a second end of the second common mode inductor L2, a second end of the third Y capacitor Y3 and a second end of the fourth Y capacitor Y4 are electrically connected to a second ground GND2, a third end of the first common mode inductor L1 is electrically connected to a first end of the second common mode inductor L2, and a fourth end of the first common mode inductor L1 is electrically connected to a second end of the second common mode inductor L2.
In the above scheme, the second end of the first Y capacitor and the second end of the second Y capacitor are respectively electrically connected to the first ground terminal, and the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected to the second ground terminal, that is, the Y capacitor in the first filter unit and the Y capacitor in the second filter unit are designed to be connected to different ground terminals, so that the transmission of the common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
In an embodiment of the present application, as shown in fig. 3, the first filter unit further includes a first X capacitor X1, the second filter unit further includes a second X capacitor X2, a first end of the first X capacitor X1 is electrically connected to a first end of the first common mode inductor L1, a second terminal of the first X capacitor X1 is electrically connected to a second terminal of the first common mode inductor L1, and the first end of the first Y capacitor Y1 is located on the branch between the first end of the first X capacitor X1 and the first end of the first common mode inductor L1, a first terminal of the second Y capacitor Y2 is connected to a branch between a second terminal of the first X capacitor X1 and a second terminal of the first common mode inductor L1, a first terminal of the second X capacitor X2 is electrically connected to a third terminal of the second common mode inductor L2, a second terminal of the second X capacitor X2 is electrically connected to a fourth terminal of the second common mode inductor L2. The transfer of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
In an embodiment of the present application, the filter circuit further includes: one or more third filter units including a third common mode inductor L3, the third filter unit being connected in series between the first filter unit and the second filter unit. When one third filtering unit is provided, the three-stage filtering circuit is adopted, when two third filtering units are provided, the four-stage filtering circuit is adopted, and the like.
In an embodiment of the present invention, as shown in fig. 4, the third filtering unit further includes a third X capacitor X3, a fifth Y capacitor Y5, and a sixth Y capacitor Y6, a third end of the first common mode inductor L1 is electrically connected to a first end of the third common mode inductor L3, a fourth end of the first common mode inductor L1 is electrically connected to a second end of the third common mode inductor L3, a third end of the third common mode inductor L3 is electrically connected to a first end of the second common mode inductor L2, a fourth end of the third common mode inductor L3 is electrically connected to a second end of the second common mode inductor L2, a first end of the fifth Y capacitor Y5 is electrically connected to a second end of the first common mode inductor L1, a first end of the sixth Y capacitor Y6 is electrically connected to a fourth end of the third common mode inductor L1, a second end of the fifth Y capacitor Y5 is electrically connected to a third end of the sixth common mode capacitor Y6 and a third end 3, a first end of the third X capacitor X3 is connected to a branch between a first end of the fifth Y capacitor Y5 and a first end of the third common mode inductor L3, and a second end of the third X capacitor X3 is connected to a branch between a second end of the sixth Y capacitor Y6 and a second end of the third common mode inductor L3. The near-field coupling between the common-mode inductors of all levels is reduced to the minimum, the interference is reduced to the maximum extent, and the external interference and radiation of the product are reduced; the interference suppression of a high frequency band is realized at low cost, and the high frequency effect is good; greatly reduces the electromagnetic compatibility risk of the product and has great practical value. The universality is strong, the number of the magnetic rings is reduced, the cost is low, and the safety and the reliability are realized. The grounding is flexible and practical, the mode is novel, and the high-frequency interference suppression effect is obvious.
Specifically, as shown in fig. 4, the Y capacitor bypass path is optimally designed, the Y capacitor is connected behind each stage of common mode inductor for filtering, the preceding stages Y5 and Y6, Y3 and Y4 of the Y capacitor at each stage are grounded respectively (here, the ground terminal or the ground line can be externally connected or can be connected to the chassis conductor by punching), and the final stages Y1 and Y2 of the Y capacitor can be directly connected to the power ground line or the chassis of the power ground line terminal, so as to improve the high-frequency bypass effect, further reduce the near-field coupling between the common mode inductors, suppress the high-frequency interference, block the transmission of the common ground interference through the respective ground processing at each stage, avoid the interference from being communicated with each other through the Y capacitor, disable the filtering effect of the filter inductor, reduce the near-field coupling through the inductor to transmit the interference signal, and facilitate the EMI rectification and reduce the cost.
Specifically, fig. 5 shows an overall PCB layout of the three-stage filter circuit in fig. 4, and the three-stage filter circuit is fabricated by using the overall PCB layout shown in fig. 5.
In a preferred embodiment, as shown in fig. 6, the filter circuit further includes a first magnetic loop module M1, a second magnetic loop module M2, and a third magnetic loop module M3, a first end of the first magnetic ring module M1 is electrically connected to a second end of the first Y capacitor Y1 and a second end of the second Y capacitor Y2, a second end of the first magnetic ring module M1 is electrically connected to the first ground GND1, a first end of the second magnetic ring module M2 is electrically connected to a second end of the third Y capacitor Y3 and a second end of the fourth Y capacitor Y4, a second end of the second magnetic ring module M2 is electrically connected to the second ground, a first end of the third magnetic ring module M3 is electrically connected to a second end of the fifth Y capacitor Y5 and a second end of the sixth Y capacitor Y6, a second end of the third magnetic ring module M3 is electrically connected to the third ground GND 3. By adding the first magnetic ring module M1, the second magnetic ring module M2 and the third magnetic ring module M3, the interference suppression effect is increased, and the high-frequency filtering effect is enhanced. The magnetic ring is sleeved on the wiring, which is equivalent to that a nonlinear impedance is connected in series on the wiring, and physically, the magnetic ring changes the local high-frequency circuit parameters of the wiring, increases the loop impedance of the wiring, thereby increasing the loss of high-frequency energy, damping the propagation of the high-frequency energy and inhibiting the interference current.
Specifically, the material of the first magnetic ring module M1, the material of the second magnetic ring module M2, and the material of the third magnetic ring module M3 are one of the following: ferrite, amorphous and metallic magnetic powder cores. Of course, other materials than ferrite, amorphous and metallic magnetic powder cores may be used.
In a preferred embodiment, as shown in fig. 7, the filter circuit further includes a fourth magnetic ring module M4, a first resistor module R1, and a second resistor module R2, a first end of the fourth magnetic ring module M4 is electrically connected to the second end of the first Y capacitor Y1 and the second end of the second Y capacitor Y2, a second end of the fourth magnetic ring module M4 is electrically connected to the first ground GND1, a first end of the first resistor module R1 is electrically connected to a second end of the third Y capacitor Y3 and a second end of the fourth Y capacitor Y4, a second terminal of the first resistor block R1 is electrically connected to the second ground GND2, a first terminal of the second resistor block R2 is electrically connected to a second terminal of the fifth Y capacitor Y5 and a second terminal of the sixth Y capacitor Y6, the second terminal of the second resistor module R2 is electrically connected to the third ground GND 3. The fourth magnetic ring module M4, the first resistance module R1 and the second resistance module R2 are added to form a resonant circuit, so that the interference suppression effect is increased, and the high-frequency filtering effect is enhanced.
In a preferred embodiment, as shown in fig. 8, the filter circuit further includes a fifth magnetic loop module M5, a first inductor module L1, and a second inductor module L2, a first end of the fifth magnetic loop module M5 is electrically connected to the second end of the first Y capacitor Y1 and the second end of the second Y capacitor Y2, a second end of the fifth magnetic loop module M5 is electrically connected to the first ground GND1, a first end of the first inductor module L1 is electrically connected to a second end of the third Y capacitor Y3 and a second end of the fourth Y capacitor Y4, a second terminal of the first inductor module L1 is electrically connected to the second ground GND2, a first terminal of the second inductor module L2 is electrically connected to a second terminal of the fifth Y capacitor Y5 and a second terminal of the sixth Y capacitor Y6, a second terminal of the second inductor module L2 is electrically connected to the third ground GND 3. The fifth magnetic ring module M5, the first inductance module L1 and the second inductance module L2 are added to form a resonance circuit, so that the interference suppression effect is increased, and the high-frequency filtering effect is enhanced.
Specifically, the first Y capacitor Y1, the second Y capacitor Y2, the third Y capacitor Y3, the fourth Y capacitor Y4, the fifth Y capacitor and the sixth Y capacitor are typically ceramic capacitors or thin film capacitors, and the capacitance value is typically 1nF-100nF, which is much larger than the parasitic capacitance of the common mode choke. The impedance of the Y capacitor and the Y capacitor is usually less than 10 omega in the frequency range of 10MHz-30MHz, and the Y capacitor play a direct connection role in the resonant current of a high-frequency end.
According to another exemplary embodiment of the present application, there is provided an electronic device including any one of the above-described filter circuits. The second end of the first Y capacitor and the second end of the second Y capacitor in the filter circuit are respectively electrically connected with a first grounding terminal, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding terminal, namely, the Y capacitor in the first filter unit and the Y capacitor in the second filter unit are designed to be connected with different grounding terminals, so that the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
According to yet another exemplary embodiment of the present application, an electrical appliance is provided, comprising any one of the above-described filter circuits. The second end of the first Y capacitor and the second end of the second Y capacitor in the filter circuit are respectively electrically connected with a first grounding terminal, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding terminal, namely, the Y capacitor in the first filter unit and the Y capacitor in the second filter unit are designed to be connected with different grounding terminals, so that the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
Examples
The embodiment relates to an interference source of more than 10M, a filter circuit shown in figure 1 is utilized to test conducted EMI, and as a result is shown in figure 9, the reason that the high-frequency suppression effect is poor is mainly that the common-mode inductance and the capacitor cannot achieve good interference suppression effect because near-field coupling between the common-mode inductances is transmitted through a common ground line when the frequency is high, in this case, only common-mode inductance parameters can be adjusted, an amorphous/nanocrystalline common-mode choke coil with better high-frequency impedance characteristic is selected to suppress interference, and meanwhile, magnetic rings (1-2) need to be added at the power supply inlet wire to suppress low-frequency interference; if the filter circuits shown in fig. 4, 6, 7 and 8 are used, the grounding effect is improved by processing in different levels, the transmission of common ground interference is blocked, and coupling is reduced; the usage of magnetic rings at the power supply inlet wire can be reduced, and the cost for replacing the high-cost common mode inductor is reduced, and the final effect is shown in figure 10. The comparison can be obtained, and the effect of the high-frequency filtering of the filter circuit adopting the scheme is superior to that of the scheme in the prior art.
From the above description, it can be seen that the above-described embodiments of the present application achieve the following technical effects:
1) the second end of the first Y capacitor and the second end of the second Y capacitor are respectively electrically connected with a first grounding end of a first grounding end, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding end of a second grounding end, namely different grounding ends are connected through the Y capacitor in the first filtering unit and the Y capacitor in the second filtering unit, and the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
2) The second end of the first Y capacitor and the second end of the second Y capacitor in the filter circuit are respectively electrically connected with a first grounding end of a first grounding end, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding end of a second grounding end, namely, the Y capacitor in the first filter unit and the Y capacitor in the second filter unit are designed to be connected with different grounding ends, and the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
3) The second end of the first Y capacitor and the second end of the second Y capacitor in the filter circuit are respectively electrically connected with a first grounding end of a first grounding end, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding end of a second grounding end, namely different grounding ends are connected through the Y capacitor in the first filter unit and the Y capacitor in the second filter unit, and the transmission of common ground interference is blocked. And simultaneously, high-frequency electromagnetic interference can be suppressed.
The above description is only a preferred embodiment of the present application and is not intended to limit the present application, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present application shall be included in the protection scope of the present application.
Claims (10)
1. A filter circuit, comprising:
the first filtering unit comprises a first common-mode inductor, a first Y capacitor and a second Y capacitor, wherein a first end of the first Y capacitor is electrically connected with a first end of the first common-mode inductor, a first end of the second Y capacitor is electrically connected with a second end of the first common-mode inductor, and a second end of the first Y capacitor and a second end of the second Y capacitor are respectively electrically connected with a first grounding end;
the second filtering unit comprises a second common-mode inductor, a third Y capacitor and a fourth Y capacitor, wherein the first end of the third Y capacitor is electrically connected with the first end of the second common-mode inductor, the first end of the fourth Y capacitor is electrically connected with the second end of the second common-mode inductor, the second end of the third Y capacitor and the second end of the fourth Y capacitor are respectively electrically connected with a second grounding end, the third end of the first common-mode inductor is electrically connected with the first end of the second common-mode inductor, and the fourth end of the first common-mode inductor is electrically connected with the second end of the second common-mode inductor.
2. The filter circuit of claim 1, wherein the first filter unit further comprises a first X capacitor, the second filtering unit further comprises a second X capacitor, a first end of the first X capacitor is electrically connected with a first end of the first common mode inductor, a second end of the first X capacitor is electrically connected with a second end of the first common mode inductor, and the first end of the first Y capacitor is located on the branch between the first end of the first X capacitor and the first end of the first common mode inductor, a first end of the second Y capacitor is connected to a branch between a second end of the first X capacitor and a second end of the first common mode inductor, the first end of the second X capacitor is electrically connected with the third end of the second common-mode inductor, and the second end of the second X capacitor is electrically connected with the fourth end of the second common-mode inductor.
3. The filter circuit according to claim 1 or 2, wherein the filter circuit further comprises:
one or more third filtering units including a third common mode inductor, the third filtering unit being connected in series between the first filtering unit and the second filtering unit.
4. The filter circuit according to claim 3, wherein the third filter unit further comprises a third X capacitor, a fifth Y capacitor and a sixth Y capacitor, the third terminal of the first common-mode inductor is electrically connected to the first terminal of the third common-mode inductor, the fourth terminal of the first common-mode inductor is electrically connected to the second terminal of the third common-mode inductor, the third terminal of the third common-mode inductor is electrically connected to the first terminal of the second common-mode inductor, the fourth terminal of the third common-mode inductor is electrically connected to the second terminal of the second common-mode inductor, the first terminal of the fifth Y capacitor is electrically connected to the third terminal of the first common-mode inductor, the first terminal of the sixth Y capacitor is electrically connected to the fourth terminal of the first common-mode inductor, the second terminal of the fifth Y capacitor and the second terminal of the sixth Y capacitor are respectively electrically connected to a third ground terminal, the first end of the third X capacitor is connected to a branch between the first end of the fifth Y capacitor and the first end of the third common mode inductor, and the second end of the third X capacitor is connected to a branch between the second end of the sixth Y capacitor and the second end of the third common mode inductor.
5. The filter circuit according to claim 4, further comprising a first magnetic loop module, a second magnetic loop module, and a third magnetic loop module, wherein a first end of the first magnetic loop module is electrically connected to a second end of the first Y capacitor and a second end of the second Y capacitor, respectively, a second end of the first magnetic loop module is electrically connected to the first ground terminal, a first end of the second magnetic loop module is electrically connected to a second end of the third Y capacitor and a second end of the fourth Y capacitor, respectively, a second end of the second magnetic loop module is electrically connected to the second ground terminal, a first end of the third magnetic loop module is electrically connected to a second end of the fifth Y capacitor and a second end of the sixth Y capacitor, respectively, and a second end of the third magnetic loop module is electrically connected to the third ground terminal.
6. The filter circuit of claim 5, wherein the material of the first magnetic loop module, the material of the second magnetic loop module, and the material of the third magnetic loop module are one of:
ferrite, amorphous and metallic magnetic powder cores.
7. The filter circuit according to claim 4, further comprising a fourth magnetic loop module, a first resistor module, and a second resistor module, wherein a first end of the fourth magnetic loop module is electrically connected to the second end of the first Y capacitor and the second end of the second Y capacitor, respectively, a second end of the fourth magnetic loop module is electrically connected to the first ground terminal, a first end of the first resistor module is electrically connected to the second end of the third Y capacitor and the second end of the fourth Y capacitor, respectively, a second end of the first resistor module is electrically connected to the second ground terminal, a first end of the second resistor module is electrically connected to the second end of the fifth Y capacitor and the second end of the sixth Y capacitor, respectively, and a second end of the second resistor module is electrically connected to the third ground terminal.
8. The filter circuit according to claim 4, further comprising a fifth magnetic loop module, a first inductor module, and a second inductor module, wherein a first end of the fifth magnetic loop module is electrically connected to the second end of the first Y capacitor and the second end of the second Y capacitor, respectively, a second end of the fifth magnetic loop module is electrically connected to the first ground terminal, a first end of the first inductor module is electrically connected to the second end of the third Y capacitor and the second end of the fourth Y capacitor, respectively, a second end of the first inductor module is electrically connected to the second ground terminal, a first end of the second inductor module is electrically connected to the second end of the fifth Y capacitor and the second end of the sixth Y capacitor, respectively, and a second end of the second inductor module is electrically connected to the third ground terminal.
9. An electronic device, characterized in that it comprises a filter circuit according to any one of claims 1 to 8.
10. An electrical appliance, characterized in that it comprises a filter circuit according to any one of claims 1 to 8.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110909554.3A CN113595378A (en) | 2021-08-09 | 2021-08-09 | Filter circuit, electronic device and electric appliance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202110909554.3A CN113595378A (en) | 2021-08-09 | 2021-08-09 | Filter circuit, electronic device and electric appliance |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN113595378A true CN113595378A (en) | 2021-11-02 |
Family
ID=78256496
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202110909554.3A Pending CN113595378A (en) | 2021-08-09 | 2021-08-09 | Filter circuit, electronic device and electric appliance |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN113595378A (en) |
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2021
- 2021-08-09 CN CN202110909554.3A patent/CN113595378A/en active Pending
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