Common mode filter and data transmission system

Abstract

The application provides a common mode filter and a data transmission system, and belongs to the technical field of electronics. The common mode filter comprises a first magnetic layer and a second magnetic layer; M differential coupling components are sequentially stacked and insulated from each other between the first magnetic layer and the second magnetic layer, each differential coupling component comprises at least two coil conductors which are co-directionally surrounded and insulated from each other; the common mode filter further comprises N first electrodes and N second electrodes; each first electrode corresponds to one second electrode, and each first electrode and the corresponding second electrode are used for transmitting a differential signal; each first electrode is electrically connected with one coil conductor in N-1 differential coupling components, the corresponding N-1 coil conductors are electrically connected with the corresponding second electrode; and the coil conductors electrically connected with different first electrodes are different. The application solves the symmetry requirement that cannot be met by three-wire differential, and improves signal integrity, anti-interference capability and electromagnetic compatibility.

Description

Technical Field

[0001] This application relates to the field of electronic technology, and in particular to a common-mode filter and a data transmission system. Background Technology

[0002] In high-speed serial data transmission systems, especially in scenarios using differential signal transmission technology, common-mode filters (CMFs) are widely used to suppress common-mode noise.

[0003] In related technologies, it is difficult for multiple coils in a multi-line common-mode filter to meet the symmetry requirements, which leads to the mutual conversion between differential-mode and common-mode signals, causing frequency and time domain imbalance of multiple signals, and thus resulting in a decrease in the performance of the multi-line common-mode filter. Summary of the Invention

[0004] This application provides a common-mode filter and a data transmission system that can solve the problem that it is difficult for multiple coils in a multi-line common-mode filter to meet the symmetry requirements, which leads to a decrease in the performance of the multi-line common-mode filter.

[0005] The technical solution is as follows:

[0006] On one hand, a common-mode filter is provided, the common-mode filter comprising: a first magnetic layer and a second magnetic layer arranged opposite to each other along a first direction;

[0007] Between the first magnetic layer and the second magnetic layer, there are M differential coupling components that are stacked sequentially and insulated from each other. Each differential coupling component includes at least two coil conductors that are wound in the same direction and insulated from each other, where M is an integer greater than or equal to 3.

[0008] It also includes N first electrodes and N second electrodes;

[0009] Each of the first electrodes corresponds to one of the second electrodes, and each of the first electrodes and the corresponding second electrodes is used to transmit a differential signal, where N is an integer greater than or equal to 3 and less than or equal to M;

[0010] Each of the first electrodes is electrically connected to one of the coil conductors in the N-1 differential coupling components, and the corresponding N-1 coil conductors are electrically connected to the corresponding second electrode; the coil conductors electrically connected to the different first electrodes are different.

[0011] In some embodiments, wherein,

[0012]

[0013] In some embodiments, N first electrodes are respectively located on a first side of the common-mode filter, and N second electrodes are respectively located on a second side of the common-mode filter, with the first side and the second side being arranged opposite to each other.

[0014] In some embodiments, the first electrode and the second electrode each include a pole post extending along the first direction and a connecting plate located at both ends of the pole post, wherein one of the connecting plates is located outside the first magnetic layer and the other connecting plate is located outside the second magnetic layer.

[0015] In some embodiments, the common-mode filter further includes an insulating medium that fills between the first magnetic layer and the second magnetic layer and encapsulates the differential coupling component, the first electrode, and the second electrode, respectively.

[0016] In some embodiments, at least two coil conductors of the same differential coupling component have the same trace length;

[0017] And / or,

[0018] All the coil conductors in the M differential coupling components have the same trace length.

[0019] In some embodiments, at least one of the at least two coil conductors includes a waveform trace segment for increasing the trace length of the coil conductor.

[0020] In some embodiments, each of the differential coupling components includes two coil conductors, which are co-layered, co-directional, and mutually insulated.

[0021] In some embodiments, each of the differential coupling components includes four coil conductors, wherein two of the coil conductors are wound in the same direction on the same layer to form a first coil group, and the other two coil conductors are wound in the same direction on the same layer to form a second coil group, and the first coil group and the second coil group are arranged at intervals along the first direction;

[0022] One of the coil conductors in the first coil group is electrically connected to one of the coil conductors in the second coil group along the first direction, and the other coil conductor in the first coil group is electrically connected to another coil conductor in the second coil group along the first direction.

[0023] In some embodiments, the turn spacing of each coil conductor in each differential coupling assembly is the same, and the spacing between two coil conductors that are wrapped in the same direction on the same layer is the same.

[0024] In some embodiments, M = 3 and N = 3.

[0025] On the other hand, a data transmission system is provided, which includes the common-mode filter described in this application.

[0026] The beneficial effects of the technical solution provided in this application include at least the following:

[0027] The common-mode filter of this application has M differential coupling components arranged between the first and second magnetic layers stacked at intervals. Each differential coupling component includes multiple mutually insulated coil conductors. These coil conductors can be connected between different first and second electrodes. The number of first and second electrodes depends on the number of differential signals that the common-mode filter can support. Each first electrode and its corresponding second electrode correspond to a differential signal. These differential signals can be arranged in pairs. The two differential signals in each arrangement are passed into two different coil conductors in a differential coupling component. By utilizing the unidirectional insulation characteristics of the coil conductors, the common-mode noise between the two differential signals can be effectively attenuated, thereby improving the integrity and transmission efficiency of the two differential signals.

[0028] For multi-channel differential signals, splitting and rearranging them before performing two-line differential processing improves the symmetry of the differential signal, solves the symmetry requirements that are difficult to meet with three-line differential signals, avoids the mutual conversion between differential and common-mode signals, and addresses the imbalance between the frequency and time domains. This also improves the signal integrity, anti-interference capability, and electromagnetic compatibility of the common-mode filter, thereby meeting the stringent requirements of modern high-speed data transmission systems for signal quality and EMC performance. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the common-mode filter provided in the embodiments of this application;

[0031] Figure 2 This is a schematic diagram of the internal structure of the common-mode filter provided in the embodiments of this application;

[0032] Figure 3 This is a side view of the internal structure of the common-mode filter provided in the embodiments of this application;

[0033] Figure 4 This is a schematic diagram of the structure of the first coil conductor and the second coil conductor provided in the embodiments of this application;

[0034] Figure 5 This is a schematic diagram of the structure of the third and fourth coil conductors provided in the embodiments of this application;

[0035] Figure 6 This is a schematic diagram of the structure of the fifth and sixth coil conductors provided in the embodiments of this application;

[0036] Figure 7 This is a schematic diagram of the structure of the seventh and eighth coil conductors provided in the embodiments of this application;

[0037] Figure 8 This is a schematic diagram of the structure of the ninth and tenth coil conductors provided in the embodiments of this application;

[0038] Figure 9 This is a schematic diagram of the structure of the eleventh coil conductor and the twelfth coil conductor provided in the embodiments of this application;

[0039] Figure 10 This is an equivalent circuit diagram of the first differential coupling component provided in the embodiments of this application;

[0040] Figure 11 This is an equivalent circuit diagram of the second differential coupling component provided in the embodiments of this application;

[0041] Figure 12 This is an equivalent circuit diagram of the third differential coupling component provided in the embodiments of this application;

[0042] Figure 13 This is a diagram illustrating the differential loss effect of the common-mode filter provided in this embodiment of the application;

[0043] Figure 14 This is a diagram illustrating the common-mode suppression effect of the common-mode filter provided in the embodiments of this application;

[0044] Figure 15 This is a differential phase effect diagram of the common-mode filter provided in the embodiments of this application.

[0045] The reference numerals in the figure are respectively:

[0046] a) First direction; 001) First side; 002) Second side;

[0047] 1. First magnetic layer;

[0048] 2. Second magnetic layer;

[0049] 3. Differential coupling components;

[0050] 301. First differential coupling component; 302. Second differential coupling component; 303. Third differential coupling component;

[0051] 31. Coil conductor; 3101. First coil group; 3102. Second coil group; 311. Waveform trace segment;

[0052] 31A1, first coil conductor; 31A2, second coil conductor;

[0053] 31B1, the third coil conductor; 31B2, the fourth coil conductor;

[0054] 31C1, fifth coil conductor; 31C2, sixth coil conductor;

[0055] 31D1, seventh coil conductor; 31D2, eighth coil conductor;

[0056] 31E1, Ninth coil conductor; 31E2, Tenth coil conductor;

[0057] 31F1, eleventh coil conductor; 31F2, twelfth coil conductor;

[0058] 32. Metal vias;

[0059] 32A1, First metal via; 32A2, Second metal via;

[0060] 32B1, third metal via; 32B2, fourth metal via;

[0061] 32C1, fifth metal via; 32C2, sixth metal via;

[0062] 4. First electrode;

[0063] 401. Pole post; 402. Connecting plate;

[0064] 41. First electrode A; 42. First electrode B; 43. First electrode C;

[0065] 5. Second electrode;

[0066] 51. Second electrode A; 52. Second electrode B; 53. Second electrode C;

[0067] 6. Insulating medium. Detailed Implementation

[0068] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0069] In the description of this application, it should be understood that the terms "center," "longitudinal," "transverse," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the appendix. Figure 1 The orientations or positional relationships shown are for the purpose of facilitating and simplifying the description of this application, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0070] It should be understood that in this application, "electrical connection" can be understood as physical contact and electrical conduction between components; it can also be understood as a form of connection between different components in a circuit structure through physical lines that can transmit electrical signals, such as copper foil or wires on a printed circuit board (PCB). "Communication connection" can refer to the transmission of electrical signals, including wireless communication connections and wired communication connections. Wireless communication connections do not require a physical medium and are not a connection relationship that limits the product structure. "Connection" and "connected" can both refer to a mechanical or physical connection relationship, that is, A and B being connected or connected can mean that there are fastening components (such as screws, bolts, rivets, etc.) between A and B, or that A and B are in contact with each other and are difficult to separate.

[0071] Unless otherwise defined, all technical terms used in the embodiments of this application have the same meaning as commonly understood by one of ordinary skill in the art.

[0072] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0073] On the one hand, combined with Figure 1 and Figure 2 As shown, this embodiment provides a common-mode filter, which includes a first magnetic layer 1 and a second magnetic layer 2 arranged opposite to each other along a first direction a.

[0074] Between the first magnetic layer 1 and the second magnetic layer 2, there are M differential coupling components 3 stacked sequentially and insulated from each other. Each differential coupling component 3 includes at least two coil conductors 31 that are wound in the same direction and insulated from each other, where M is an integer greater than or equal to 3.

[0075] It also includes N first electrodes 4 and N second electrodes 5; each first electrode 4 corresponds to one second electrode 5, and each first electrode 4 and the corresponding second electrode 5 are used to transmit a differential signal, where N is an integer greater than or equal to 3 and less than or equal to M; each first electrode 4 is electrically connected to one of the coil conductors 31 in N-1 differential coupling components 3, and the corresponding N-1 coil conductors 31 are electrically connected to the corresponding second electrode 5; the coil conductors 31 electrically connected to different first electrodes 4 are different.

[0076] In this embodiment, the common-mode filter has M differential coupling components 3 arranged between the first magnetic layer 1 and the second magnetic layer 2 stacked at intervals. Each differential coupling component 3 includes multiple mutually insulated coil conductors 31. These coil conductors 31 can be connected between different first electrodes 4 and second electrodes 5. The number of first electrodes 4 and second electrodes 5 depends on the number of differential signals that the common-mode filter can support. Each first electrode 4 and its corresponding second electrode 5 correspond to a differential signal. These differential signals can be arranged in pairs. The two differential signals in each arrangement are passed into two different coil conductors 31 in a differential coupling component 3. By utilizing the unidirectional insulation characteristics of the coil conductors 31, the common-mode noise between the two differential signals can be effectively attenuated, thereby improving the integrity and transmission efficiency of the two differential signals.

[0077] For multi-channel differential signals, splitting and rearranging them before performing two-line differential processing improves the symmetry of the differential signal, solves the symmetry requirements that are difficult to meet with three-line differential signals, avoids the mutual conversion between differential and common-mode signals, and addresses the imbalance between the frequency and time domains. This also improves the signal integrity, anti-interference capability, and electromagnetic compatibility of the common-mode filter, thereby meeting the stringent requirements of modern high-speed data transmission systems for signal quality and EMC performance.

[0078] To clearly demonstrate the operation of the common-mode filter in this embodiment, taking a C-PHY three-wire differential transmission interface as an example, the process of using the common-mode filter of this embodiment to perform common-mode filtering on three types of differential signals is described in detail below:

[0079] First, the three signals in the C-PHY three-wire differential transmission interface are defined as signal A, signal B, and signal C, which have three different permutations and combinations, namely AB, AC, and BC.

[0080] Signal A is transmitted using a set of first electrodes 4 and second electrodes 5; signal B is transmitted using a set of first electrodes 4 and second electrodes 5; signal C is transmitted using a set of first electrodes 4 and second electrodes 5.

[0081] Signal A will be transmitted by the corresponding first electrode 4 and second electrode 5 to one coil conductor 31 of a differential coupling component 3 and another coil conductor 31 of a differential coupling component 3, respectively; similarly, signal B will also be transmitted by the corresponding first electrode 4 and second electrode 5 to one coil conductor 31 of a differential coupling component 3 and another coil conductor 31 of a differential coupling component 3, respectively; signal C will also be transmitted by the corresponding first electrode 4 and second electrode 5 to one coil conductor 31 of a differential coupling component 3 and another coil conductor 31 of a differential coupling component 3, respectively.

[0082] Within one of the differential coupling components 3, one coil conductor 31 is supplied with signal A, and the other coil conductor 31 is supplied with signal B. This differential coupling component 3 corresponds to the arrangement and combination of A and B, realizing common-mode filtering of signals A and B.

[0083] In another differential coupling component 3, one coil conductor 31 is supplied with an A signal and the other coil conductor 31 is supplied with a C signal. This differential coupling component 3 corresponds to the arrangement and combination of AC signals, realizing common-mode filtering of the A and C signals.

[0084] In another differential coupling component 3, one coil conductor 31 is supplied with a B signal and the other coil conductor 31 is supplied with a C signal. This differential coupling component 3 corresponds to the arrangement and combination of B and C, realizing common-mode filtering of the B and C signals.

[0085] Therefore, the common-mode filter in this embodiment inputs the three signals in the C-PHY three-wire differential transmission interface into different differential coupling components 3 in a pairwise combination manner for dual-wire common-mode coupling. It has higher symmetry and can effectively reduce insertion loss, delay difference and improve mode conversion performance while maintaining high performance.

[0086] In some possible implementations, one of the first electrode 4 and the second electrode 5 is used for the input of the differential signal, and the other is used for the output of the differential signal.

[0087] For example, the first electrode 4 is used as the input of the differential signal, and the second electrode 5 is used as the output of the differential signal. In another example, the second electrode 5 is used as the input of the differential signal, and the first electrode 4 is used as the output of the differential signal.

[0088] In some possible implementations, the number of at least two coil conductors 31 in each differential coupling component 3 can be two, three, etc. When two differential signals are respectively passed through two coil conductors 31 that are wound in the same direction and insulated from each other, if the currents of the two differential signals are the same in magnitude but opposite in direction, the magnetic fields generated by the two coil conductors 31 are equal in magnitude but opposite in direction, and the total magnetic flux cancels each other out. The coil conductors 31 exhibit low inductive reactance, and the differential signals can pass through with almost no attenuation, maintaining the integrity of data transmission. However, once common-mode noise exists in the two differential signals, the currents in the two coil conductors 31 are in the same direction, the magnetic fields are in the same direction, the total magnetic flux is superimposed, the coil conductors 31 exhibit high impedance characteristics, the high-frequency common-mode current is significantly attenuated due to the high impedance, while the differential signals are unaffected.

[0089] In some embodiments, wherein,

[0090]

[0091] Where N! represents the factorial of N, and (N-2)! represents the factorial of N-2. For example, when N=3, N! = 3×2×1, (N-2)! = (3-2)! = 1! = 1; when N=4, N! = 4×3×2×1, (N-2)! = (4-2)! = 2! = 2×1 = 2.

[0092] With the above arrangement, in the common-mode filter provided in this embodiment, the number of electrodes determines how many differential signals the common-mode filter can achieve common-mode filtering, and the number of differential coupling components 3 can be calculated and determined by the number of electrodes. Thus, the common-mode filter can input N differential signals into different differential coupling components 3 in a pairwise combination to perform bi-line common-mode coupling, which has higher symmetry and can effectively reduce insertion loss, delay difference and improve mode conversion performance while maintaining high performance.

[0093] For example, when N=3, then M=3! / (2×1!)=3, that is, when the number of the first electrode 4 and the second electrode 5 are both 3, the number of differential coupling components 3 is 3. At this time, the common-mode filter can perform common-mode filtering on the 3 differential signals.

[0094] In another example, when N=4, then M=4! / (2×2!)=6, meaning that when there are 4 first electrodes 4 and 4 second electrodes 5, the number of differential coupling components 3 is 6. In this case, the common-mode filter can perform common-mode filtering on the 4 differential signals.

[0095] As another example, when N=5, then M=5! / (2×3!)=6, meaning that when there are 4 first electrodes 4 and 4 second electrodes 5, the number of differential coupling components 3 is 10. In this case, the common-mode filter can perform common-mode filtering on 5 differential signals.

[0096] Furthermore, when N=6, M=15, the common-mode filter can perform common-mode filtering on 6 differential signals; when N=7, M=21, the common-mode filter can perform common-mode filtering on 7 differential signals, and so on, the common-mode filter can perform common-mode filtering on 8 or more differential signals, which will not be listed here.

[0097] Combination Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, N first electrodes 4 are respectively located on the first side 001 of the common-mode filter, and N second electrodes 5 are respectively located on the second side 002 of the common-mode filter, with the first side 001 and the second side 002 arranged opposite to each other.

[0098] With the above arrangement, the first electrode 4 and the second electrode 5 are respectively concentrated on opposite sides of the common-mode filter, which can realize the centralized connection between the external circuit and the first electrode 4 and the second electrode 5, which helps to reduce the difficulty of electrical connection of the common-mode filter.

[0099] Combination Figure 1 , Figure 2 and Figure 3 As shown, in some embodiments, the first electrode 4 and the second electrode 5 each include a pole post 401 extending along a first direction a, and a connecting plate 402 located at both ends of the pole post 401, wherein one connecting plate 402 is located outside the first magnetic layer 1 and the other connecting plate 402 is located outside the second magnetic layer 2.

[0100] With the above arrangement, the pole posts 401 of the first electrode 4 and the second electrode 5 are arranged along the first direction a, so that they can be conveniently electrically connected to the coil conductors 31 in the multiple differential coupling components 3 stacked along the first direction a. The two connecting plates 402 of the first electrode 4 and the second electrode 5 are arranged outside the first magnetic layer 1 and the second magnetic layer 2, exposed on the outer surface of the entire common-mode filter, which can facilitate the centralized connection of external circuits with the first electrode 4 and the second electrode 5, and help reduce the difficulty of electrical connection of the common-mode filter.

[0101] For example, the common-mode filter is soldered to the surface of the circuit board, with the first magnetic layer 1 or the second magnetic layer 2 facing the surface of the circuit board. Multiple pads on the surface of the circuit board are respectively in contact with and soldered to the connecting plate 402 of the first pole 401 and the second pole 401.

[0102] Among some possible implementations, refer to Figure 3 As shown, the first electrode 4 and the second electrode 5 are located in a C-shaped structure formed by two connecting plates 402 and a pole post 401, respectively.

[0103] Combination Figure 1 As shown, in some embodiments, the common-mode filter further includes an insulating medium 6, which fills the space between the first magnetic layer 1 and the second magnetic layer 2, and respectively encapsulates the differential coupling component 3, the first electrode 4, and the second electrode 5.

[0104] Through the above arrangement, the insulating medium 6 can achieve electrical insulation between the coil conductor 31, the first electrode 4, and the second electrode 5 in the differential coupling component 3, so that the differential signal can be connected along the preset circuit structure, and play the role of common mode filtering.

[0105] In some possible implementations, the insulating medium 6 includes ceramic or ceramic composite materials, which serve to provide an electrically insulating environment for the interior of the common-mode filter.

[0106] Combination Figures 6 to 9 As shown, in some embodiments, at least two coil conductors 31 of the same differential coupling component 3 have the same trace length.

[0107] With the above arrangement, the trace lengths of the coil conductors 31 within the same differential coupling component 3 are the same, which can ensure higher symmetry between the two coil conductors 31. Moreover, the consistent length can minimize the time delay difference when the two differential signals propagate between different channels.

[0108] Combination Figures 6 to 9 As shown, in some embodiments, all the coil conductors 31 in the M differential coupling components 3 have the same trace length.

[0109] With the above arrangement, the trace lengths of the coil conductors 31 in all differential coupling components 3 in the common-mode filter are the same, which can ensure that all coil conductors 31 have higher symmetry and consistent length, and can minimize the time delay difference when all differential signals propagate between different channels.

[0110] Combination Figures 6 to 9 As shown, in some embodiments, at least one of the at least two coil conductors 31 includes a waveform trace segment 311, which is used to increase the trace length of the coil conductor 31.

[0111] In this embodiment, since the coil conductors 31 in the differential coupling component 3 are all in the same direction, due to objective limitations, the outer coil conductor 31 must be longer than the inner coil conductor 31. Therefore, by adding a waveform trace segment 311 to the shorter coil conductor 31, the trace length of the coil conductor 31 can be increased within a limited space, ensuring that the length of the coil conductors 31 is consistent.

[0112] Combination Figures 4 to 9As shown, in some embodiments, each differential coupling component 3 includes two coil conductors 31, which are wrapped in the same layer in the same direction and are insulated from each other.

[0113] With the above arrangement, the two coil conductors 31 in the differential coupling component 3 are arranged in a co-layer, which helps to reduce the thickness of each differential coupling component 3, thereby helping to reduce the thickness of the entire common-mode filter along the first direction a and reducing the volume of the common-mode filter.

[0114] Combination Figures 2 to 5 As shown, in some embodiments, each differential coupling component 3 includes four coil conductors 31, wherein two coil conductors 31 are wound in the same direction on the same layer to form a first coil group 3101, and the other two coil conductors 31 are wound in the same direction on the same layer to form a second coil group 3102. The first coil group 3101 and the second coil group 3102 are arranged at intervals along a first direction a.

[0115] One coil conductor 31 in the first coil group 3101 is electrically connected to one coil conductor 31 in the second coil group 3102 along the first direction a, and the other coil conductor 31 in the first coil group 3101 is electrically connected to the other coil conductor 31 in the second coil group 3102 along the first direction a.

[0116] Since the attenuation performance of the coil conductor 31 for common-mode noise is proportional to the trace length of the coil conductor 31, but due to the limitations of the common-mode filter volume and processing technology, the coil conductor 31 arranged in layers cannot achieve a large trace length. Therefore, in this embodiment, the coil conductor 31 is arranged in layers, and two coil conductors 31 arranged at intervals along the first direction a are connected in series to connect a larger coil conductor 31, thereby improving the attenuation performance of the coupling differential component for common-mode noise.

[0117] In some possible implementations, each differential coupling component 3 may include six coil conductors 31, with each pair forming three coil groups that are wound in the same direction, and the three coil conductors 31 in the three coil groups are electrically connected in series along the first direction a, thereby forming a larger coil conductor 31 with a three-layer arrangement.

[0118] Furthermore, the number of coil conductors 31 in the differential coupling component 3 can be any even number greater than four, with each pair forming multiple coil groups that are wound in the same direction. Subsequently, the corresponding coil conductors 31 are connected in series along the first direction a.

[0119] Among some possible implementations, refer to Figure 4 and Figure 5As shown, the outer leads of the two coil conductors 31 in the first coil group 3101 are used to electrically connect to different first electrodes 4 (or different second electrodes 5) respectively, and the inner leads of the two coil conductors 31 are used to extend along the first direction a to electrically connect to the inner leads of the two coil conductors 31 in the second coil group 3102 respectively. The outer leads of the two coil conductors 31 in the second coil group 3102 are electrically connected to the corresponding second electrodes 5 (or the corresponding first electrodes 4) respectively.

[0120] Among some possible implementations, refer to Figure 3 As shown, the coil conductors 31 in the first coil group 3101 and the coil conductors 31 in the second coil group 3102 are electrically connected through metal vias 32 arranged along the first direction a.

[0121] Combination Figures 4 to 9 As shown, in some embodiments, the turn spacing of each coil conductor 31 in each differential coupling component 3 is the same, and the spacing between two coil conductors 31 that are wound in the same direction on the same layer is the same.

[0122] With the above arrangement, the turn spacing of each coil conductor 31 in the differential coupling component 3 is the same, and the spacing between the coil conductors 31 is the same. This can ensure that the loss is balanced when the differential signal is transmitted in a single channel, effectively reduce the insertion loss and phase difference of the differential signal, and improve the integrity and transmission efficiency of the differential signal.

[0123] In some embodiments, M=3 and N=3, so the common-mode filter in this embodiment can perform common-mode filtering of three differential signals. Exemplarily, the differential signal is a MIPI C-PHY three-wire differential signal. MIPI, or Mobile Industry Processor Interface, is an open standard and specification for mobile application processors initiated by the MIPI Alliance. MIPI C-PHY three-wire differential signals are commonly used in the communication interfaces of CMOS (Complementary Metal-Oxide Semiconductor) sensors to meet the high-speed MIPI transmission rate requirements of CMOS sensors in display and image capture technologies.

[0124] Among some possible implementations, refer to Figure 2-9As shown, the differential coupling component 3 includes a first differential coupling component 301, a second differential coupling component 302, and a third differential coupling component 303. The first electrode 4 serves as the input terminal, and the second electrode 5 serves as the output terminal. The first electrode 4 includes a first electrode A41, a first electrode B42, and a first electrode C43 sequentially arranged on the first side. The second electrode 5 includes a second electrode A51, a second electrode B52, and a second electrode C53 sequentially arranged on the second side. The metal via 32 includes a first metal via 32A1, a second metal via 32A2, a third metal via 32B1, a fourth metal via 32B2, a fifth metal via 32C1, and a sixth metal via 32C2.

[0125] Among them, the first electrode A41 and the second electrode A51 correspond to the first differential signal, the first electrode B42 and the second electrode B52 correspond to the second differential signal, and the first electrode C43 and the second electrode C53 correspond to the third differential signal.

[0126] refer to Figure 4 and Figure 5 The first differential coupling component 301 includes a first coil conductor 31A1, a second coil conductor 31A2, a third coil conductor 31B1, and a fourth coil conductor 31B2. The first coil conductor 31A1 and the second coil conductor 31A2 are wrapped together in the same layer and in the same direction, with the first coil conductor 31A1 inside and the second coil conductor 31A2 outside. The third coil conductor 31B1 and the fourth coil conductor 31B2 are wrapped together in the same layer and in the same direction, with the third coil conductor 31B1 inside and the fourth coil conductor 31B2 outside.

[0127] The outer lead of the first coil conductor 31A1 is electrically connected to the first electrode A41. The inner lead of the first coil conductor 31A1 is electrically connected to the inner lead of the third coil conductor 31B1 through the first metal via 32A1. The outer lead of the third coil conductor 31B1 is electrically connected to the second electrode A51.

[0128] The outer lead of the second coil conductor 31A2 is electrically connected to the first electrode B42. The inner lead of the second coil conductor 31A2 and the inner lead of the fourth coil conductor 31B2 are electrically connected through the second metal via 32A2. The outer lead of the fourth coil conductor 31B2 is electrically connected to the second electrode B52.

[0129] refer to Figure 6 and Figure 7The second differential coupling component 302 includes a fifth coil conductor 31C1, a sixth coil conductor 31C2, a seventh coil conductor 31D1, and an eighth coil conductor 31D2. The fifth coil conductor 31C1 and the sixth coil conductor 31C2 are wrapped together in the same layer and in the same direction, with the fifth coil conductor 31C1 inside and the sixth coil conductor 31C2 outside. The seventh coil conductor 31D1 and the eighth coil conductor 31D2 are wrapped together in the same layer and in the same direction, with the seventh coil conductor 31D1 inside and the eighth coil conductor 31D2 outside.

[0130] The outer lead of the fifth coil conductor 31C1 is electrically connected to the second electrode C53. The inner lead of the fifth coil conductor 31C1 is electrically connected to the inner lead of the seventh coil conductor 31D1 through the third metal via 32B1. The outer lead of the seventh coil conductor 31D1 is electrically connected to the first electrode C43.

[0131] The outer lead of the sixth coil conductor 31C2 is electrically connected to the second electrode B52. The inner lead of the sixth coil conductor 31C2 and the inner lead of the eighth coil conductor 31D2 are electrically connected through the fourth metal via 32B2. The outer lead of the eighth coil conductor 31D2 is electrically connected to the first electrode B42.

[0132] refer to Figure 8 and Figure 9 The third differential coupling component 303 includes a ninth coil conductor 31E1, a tenth coil conductor 31E2, an eleventh coil conductor 31F1, and a twelfth coil conductor 31F2. The ninth coil conductor 31E1 and the tenth coil conductor 31E2 are wrapped together in the same direction, with the ninth coil conductor 31E1 inside and the tenth coil conductor 31E2 outside. The eleventh coil conductor 31F1 and the twelfth coil conductor 31F2 are wrapped together in the same direction, with the eleventh coil conductor 31F1 inside and the twelfth coil conductor 31F2 outside.

[0133] The outer lead of the ninth coil conductor 31E1 is electrically connected to the first electrode C43. The inner lead of the ninth coil conductor 31E1 is electrically connected to the inner lead of the eleventh coil conductor 31F1 through the first metal via 32A1. The outer lead of the eleventh coil conductor 31F1 is electrically connected to the second electrode C53.

[0134] The outer lead of the tenth coil conductor 31E2 is electrically connected to the first electrode A41. The inner lead of the tenth coil conductor 31E2 and the inner lead of the twelfth coil conductor 31F2 are electrically connected through the second metal via 32A2. The outer lead of the twelfth coil conductor 31F2 is electrically connected to the second electrode A51.

[0135] The common-mode filter process for the three differential signals in this embodiment is described as follows:

[0136] (1)Reference Figure 10 As shown, the first differential signal and the second differential signal are subjected to common-mode filtering in the first differential coupling component 301. The flow path of the first differential signal is: first electrode A41 - first coil conductor 31A1 - first metal via 32A1 - third coil conductor 31B1 - second electrode A51. The flow path of the second differential signal is: first electrode B42 - second coil conductor 31A2 - second metal via 32A2 - fourth coil conductor 31B2 - second electrode B52.

[0137] (2)Reference Figure 11 As shown, the second differential signal and the third differential signal are subjected to common-mode filtering in the second differential coupling component 302. The flow path of the second differential signal is: first electrode B42 - eighth coil conductor 31D2 - third metal via 32B1 - sixth coil conductor 31C2 - second electrode B52. The flow path of the third differential signal is: first electrode C43 - seventh coil conductor 31D1 - fourth metal via 32B2 - fifth coil conductor 31C1 - second electrode C53.

[0138] (3)Reference Figure 12 As shown, the first differential signal and the third differential signal undergo common-mode filtering within the third differential coupling component 303. The flow path of the first differential signal is: first electrode A41 - tenth coil conductor 31E2 - fifth metal via 32C1 - twelfth coil conductor 31F2 - second electrode A51. The flow path of the third differential signal is: first electrode C43 - ninth coil conductor 31E1 - sixth metal via 32C2 - eleventh coil conductor 31F1 - second electrode C53.

[0139] With the above arrangement, the common-mode filter of this embodiment can realize common-mode filtering of three differential signals. Three differential coupling components are constructed in the common-mode filter, and each component realizes magnetic coupling between a pair of differential signals. Special attention is paid to the balance problem of the three-wire differential, improving the symmetry between the two coil conductors of the magnetic coupling, and minimizing the insertion loss and phase difference between the three differential signals.

[0140] The resulting common-mode filter can effectively reduce insertion loss, delay differences, and improve mode conversion performance while maintaining high performance. It significantly improves the system's signal integrity, anti-interference ability, and electromagnetic compatibility, thereby meeting the stringent requirements of modern high-speed data transmission systems for signal quality and EMC performance.

[0141] To verify the effectiveness of the common-mode filter technology provided in this embodiment, performance tests were conducted on the differential loss, common-mode rejection, and differential phase of three differential signals, respectively, with reference to... Figure 13 It can be seen that after common-mode filtering of CA, BC, and AB, the differential loss curves of the three differential signals A, B, and C basically overlap, and are all less than 1dB below 6GHz; Reference Figure 14 It can be seen that after common-mode filtering of the three differential signals A, B, and C through CA, BC, and AB, the common-mode rejection curves basically overlap, and the suppression effect reaches -30dB at a common-mode rejection frequency of 4.22GHz; (Reference) Figure 15 It can be seen that after common-mode filtering of CA, BC, and AB, the phase curves of the three differential signals A, B, and C basically overlap, and the phase difference can be basically ignored.

[0142] On the other hand, this embodiment provides a data transmission system, which includes the common-mode filter of this application.

[0143] The data transmission system of this embodiment uses the common-mode filter of this application and has all the beneficial technical effects of this application.

[0144] It should be noted that in this article, "several" and "at least one" refer to one or more, while "multiple" and "at least two" refer to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0145] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0146] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0147] In the description of this specification, the references to the terms "certain embodiments", "one embodiment", "some embodiments", "illustrative embodiment", "example", "specific example", or "some examples" refer to specific features, structures, materials, or characteristics described in connection with the embodiments or examples that are included in at least one embodiment or example of this application.

[0148] The above description is merely an embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the principles of this application should be included within the protection scope of this application.

Claims

1. A common-mode filter, characterized in that, The common-mode filter includes: a first magnetic layer (1) and a second magnetic layer (2) arranged opposite to each other along a first direction (a); Between the first magnetic layer (1) and the second magnetic layer (2), there are M differential coupling components (3) stacked in sequence and insulated from each other. Each differential coupling component (3) includes at least two coil conductors (31) that are wound in the same direction and insulated from each other, where M is an integer greater than or equal to 3. It also includes N first electrodes (4) and N second electrodes (5); Each of the first electrodes (4) corresponds to a second electrode (5), and each of the first electrodes (4) and the corresponding second electrodes (5) is used to transmit a differential signal, where N is an integer greater than or equal to 3 and less than or equal to M; Each of the first electrodes (4) is electrically connected to one of the coil conductors (31) in the N-1 differential coupling components (3), and the corresponding N-1 coil conductors (31) are electrically connected to the corresponding second electrode (5); the coil conductors (31) electrically connected to the different first electrodes (4) are different.

2. The common-mode filter according to claim 1, characterized in that, in, 3. The common-mode filter according to claim 2, characterized in that, N first electrodes (4) are located on the first side (001) of the common-mode filter, and N second electrodes (5) are located on the second side (002) of the common-mode filter, with the first side (001) and the second side (002) arranged opposite to each other.

4. The common-mode filter according to claim 1, characterized in that, The first electrode (4) and the second electrode (5) each include a pole post (401) extending along the first direction (a) and a connecting plate (402) located at both ends of the pole post (401), wherein one of the connecting plates (402) is located outside the first magnetic layer (1) and the other connecting plate (402) is located outside the second magnetic layer (2).

5. The common-mode filter according to claim 1, characterized in that, The common-mode filter further includes an insulating medium (6), which fills the space between the first magnetic layer (1) and the second magnetic layer (2) and encapsulates the differential coupling component (3), the first electrode (4) and the second electrode (5) respectively.

6. The common-mode filter according to any one of claims 1 to 5, characterized in that, At least two coil conductors (31) of the same differential coupling component (3) have the same trace length; And / or, All of the coil conductors (31) in the M differential coupling components (3) have the same trace length.

7. The common-mode filter according to claim 6, characterized in that, At least one of the at least two coil conductors (31) includes a waveform trace segment (311) for increasing the trace length of the coil conductor (31).

8. The common-mode filter according to any one of claims 1 to 7, characterized in that, Each of the differential coupling components (3) includes two coil conductors (31) that are wrapped together in the same direction and are insulated from each other.

9. The common-mode filter according to any one of claims 1 to 8, characterized in that, Each of the differential coupling components (3) includes four coil conductors (31), wherein two of the coil conductors (31) are wrapped together in the same direction to form a first coil group (3101), and the other two coil conductors (31) are wrapped together in the same direction to form a second coil group (3102). The first coil group (3101) and the second coil group (3102) are arranged at intervals along the first direction (a). One of the coil conductors (31) in the first coil group (3101) is electrically connected to one of the coil conductors (31) in the second coil group (3102) along the first direction (a), and the other coil conductor (31) in the first coil group (3101) is electrically connected to the other coil conductor (31) in the second coil group (3102) along the first direction (a).

10. The common-mode filter according to claim 8 or 9, characterized in that, The turn spacing of each coil conductor (31) in each of the differential coupling components (3) is the same, and the spacing between two coil conductors (31) that are wrapped in the same direction in the same layer is the same.

11. The common-mode filter according to any one of claims 1 to 10, characterized in that, M = 3, and N = 3.

12. A data transmission system, characterized in that, The data transmission system includes a common-mode filter as described in any one of claims 1 to 11.

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