Device for meeting emc lightning test based on implementation of an7581 scheme of gigabit network port

Abstract

The utility model relates to a device based on AN7581 scheme's realization gigabit network port satisfies EMC thunder stroke test, including common mode inductance transformer, difference mode inductance transformer, first electric capacity, second electric capacity and damping resistance, the output of common mode inductance transformer is connected with difference mode inductance transformer, the output of difference mode inductance transformer is connected with one end of first electric capacity, the other end of first electric capacity is connected with one end of second electric capacity, the other end of second electric capacity is connected with damping resistance, and finally access to AN7581. The device based on AN7581 scheme's realization gigabit network port satisfies EMC thunder stroke test of adopting the utility model, low cost, the performance of the utility model is more excellent, can pass through EMC thunder stroke simulation test and network port consistency test, the utility model discloses the layout is flexible, can save the space at network port through the utility model, greatly reduce the difficulty of layout design. And the device application in AN7581 scheme has had the realization of production, has high reliability.

Description

Technical Field

[0001] This utility model relates to the field of network ports, and more particularly to the field of single-board EMC. Specifically, it refers to a device based on the AN7581 solution that enables gigabit network ports to meet EMC lightning strike testing requirements. Background Technology

[0002] With the increasing pursuit of miniaturization and integration of products, higher challenges have been placed on the design and layout of circuit boards. How can we ensure the safety of equipment under the 500V differential mode signal lightning strike simulation test in EMC testing while meeting the network port consistency test indicators?

[0003] The current methods for simulating lightning strike protection include the following: 1. Use shielding and a good grounding system to reduce electromagnetic interference; 2. Use filters to suppress electromagnetic interference; 3. Use devices such as TVS to suppress electromagnetic interference.

[0004] The previous design used a differential-mode inductor transformer, a single-stage capacitor, and a single-stage resistor to protect against differential-mode 500V lightning strikes. However, the signal was not adequately isolated and absorbed, causing a large voltage signal to enter the board and damage the CPU interface. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a device based on the AN7581 scheme that meets the requirements of low cost, high security, and low space occupation for gigabit network ports to meet EMC lightning strike testing.

[0006] To achieve the above objectives, the device based on the AN7581 solution of this utility model for implementing Gigabit Ethernet ports to meet EMC lightning strike testing is as follows: This device, based on the AN7581 solution, enables gigabit Ethernet ports to meet EMC lightning strike testing. Its main features include a common-mode inductor transformer, a differential-mode inductor transformer, a first capacitor, a second capacitor, and a damping resistor. The output of the common-mode inductor transformer is connected to the differential-mode inductor transformer. The output of the differential-mode inductor transformer is connected to one end of the first capacitor. The other end of the first capacitor is connected in series with one end of the second capacitor. The other end of the second capacitor is connected to the damping resistor, and finally, the connection is made to the AN7581 terminal.

[0007] Preferably, the common-mode inductor transformer filters out noise signals, the differential-mode inductor transformer buffers the signal, rectifies the current, and filters out AC signals, the first capacitor isolates DC voltage, the second capacitor provides secondary isolation of DC voltage, and the damping resistor absorbs the remaining signal and performs rectification and voltage regulation.

[0008] Preferably, the device further includes a reserved third capacitor, one end of which is connected to a damping resistor, and the other end of which is grounded.

[0009] Preferably, the third capacitor filters and absorbs the signal.

[0010] Preferably, the capacitance values ​​of the first capacitor and the second capacitor are 0.1uF.

[0011] The device based on the AN7581 solution of this invention enables gigabit Ethernet ports to meet EMC lightning strike testing requirements. It is low-cost, as the entire solution only adds a low-cost ceramic multilayer capacitor, replacing filters or TVS devices. This invention offers superior performance, passing both EMC lightning strike simulation testing and Ethernet port consistency testing. Furthermore, this invention provides flexible layout, saving space at the Ethernet port and significantly reducing the difficulty of layout design. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of port 1 and port 2 of the device based on the AN7581 scheme of this utility model to enable gigabit network ports to meet EMC lightning strike testing.

[0013] Figure 2 This is a schematic diagram of port numbers 3 and 6 of the device based on the AN7581 scheme for implementing gigabit network ports to meet EMC lightning strike testing.

[0014] Figure 3 This is a schematic diagram of port numbers 4 and 5 of the device based on the AN7581 scheme for implementing gigabit network ports to meet EMC lightning strike testing.

[0015] Figure 4 This is a schematic diagram of port numbers 7 and 8 of the device based on the AN7581 scheme for implementing gigabit network ports to meet EMC lightning strike testing.

[0016] Figure 5 This is a schematic diagram of the AN7581 main chip used in this invention to implement a gigabit Ethernet port that meets EMC lightning strike testing requirements.

[0017] Figure 6 This is a schematic diagram of the network port end of the present invention based on the AN7581 solution to achieve EMC lightning strike test compliance of the gigabit network port. Detailed Implementation

[0018] To more clearly describe the technical content of this utility model, the following description is provided in conjunction with specific embodiments.

[0019] This utility model discloses a device based on the AN7581 scheme for implementing Gigabit Ethernet ports to meet EMC lightning strike testing requirements. The device includes a common-mode inductor transformer, a differential-mode inductor transformer, a first capacitor, a second capacitor, and a damping resistor. The output terminal of the common-mode inductor transformer is connected to the differential-mode inductor transformer. The output terminal of the differential-mode inductor transformer is connected to one end of the first capacitor. The other end of the first capacitor is connected in series with one end of the second capacitor. The other end of the second capacitor is connected to the damping resistor, and the device is ultimately connected to the AN7581 terminal.

[0020] In a preferred embodiment of this utility model, the common-mode inductor transformer filters out noise signals, the differential-mode inductor transformer buffers the signal, rectifies the current, and filters out AC signals, the first capacitor isolates DC voltage, the second capacitor provides secondary isolation of DC voltage, and the damping resistor absorbs the remaining signal and performs rectification and voltage regulation.

[0021] In a preferred embodiment of this utility model, the device further includes a reserved third capacitor, one end of which is connected to a damping resistor and the other end of which is grounded, thereby enhancing reliability.

[0022] In a preferred embodiment of this utility model, the third capacitor filters and absorbs the signal.

[0023] In a preferred embodiment of this utility model, the capacitance values ​​of the first capacitor and the second capacitor are 0.1uF.

[0024] This utility model is mainly aimed at products with complex designs, strict EMC requirements, and limited PCB space. It addresses situations where these products cannot meet EMC lightning strike requirements and cost considerations necessitate a lightning strike testing solution.

[0025] This invention proposes a method for solving the problem of lightning strike simulation testing. It achieves low space occupancy while considering cost and network port design, meeting the requirements for EMC differential mode 500V lightning strike testing and network port consistency testing, thus ensuring the safety of equipment and personnel.

[0026] The original design failed to completely isolate the 500V differential signal, causing a high-voltage signal to enter the board and damage the CPU interface. Therefore, this invention, based on actual circuit testing, uses a differential-mode inductor transformer, two-stage capacitors, and resistors for signal isolation to meet the Gigabit Ethernet port EMC 500V differential-mode lightning strike test and Ethernet port consistency test requirements.

[0027] Figures 1 to 4 For the device connection method of the network cable with different serial numbers, in order to Figure 1For example, at the network port, the common-mode inductor transformer T2 first filters out noise signals, then the differential-mode inductor transformer T1 buffers the signal, mainly for current rectification and filtering out AC signals. Next, 0.1uF capacitors C3 and C5 are connected to isolate DC signals, allowing the signal to couple into the next stage. Another 0.1uF capacitor, C2 and C4, is connected for secondary DC voltage isolation, making high-voltage isolation more complete. The series connection of the two capacitors also increases the withstand voltage, fully protecting the equipment. Finally, damping resistors ER1 and ER2 are connected to absorb, rectify, and stabilize the remaining signals. Finally, capacitors C1 and C6 are reserved to ground for filtering and absorption, ensuring that the final connection to the AN7581 terminal will not cause damage.

[0028] In the specific embodiment of this utility model, as shown in the figure, each gigabit network port circuit has four sets of differential signal lines connecting the network cable and the chip end. Each set of signal lines uses double capacitors for signal isolation. The specific capacitance value can be fine-tuned according to different PCB layouts or different chips. The network port differential signal lines are connected in the order of 12, 36, 45, and 78. The AN7581 chip integrates a gigabit Ethernet port, so after the signal is protected on the network port side, it can be directly connected to the AN7581 end.

[0029] For the specific implementation scheme of this embodiment, please refer to the relevant descriptions in the above embodiments, which will not be repeated here.

[0030] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0031] It should be noted that in the description of this utility model, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this utility model, unless otherwise stated, "a plurality of" means at least two.

[0032] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0033] The device based on the AN7581 solution of this invention enables gigabit Ethernet ports to meet EMC lightning strike testing requirements. It is cost-effective, requiring only a single low-cost ceramic multilayer capacitor to replace filters or TVS devices. This invention offers superior performance, passing both EMC lightning strike simulation testing and Ethernet port consistency testing. Its flexible layout saves space at the Ethernet ports, significantly reducing the difficulty of layout design. Furthermore, this device has been mass-produced using the AN7581 solution and possesses high reliability.

[0034] In this specification, the present invention has been described with reference to specific embodiments thereof. However, it will be apparent that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the specification and drawings should be considered illustrative rather than restrictive.

Claims

1. A device based on the AN7581 scheme to enable gigabit Ethernet ports to meet EMC lightning strike testing requirements, characterized in that, The device includes a common-mode inductor transformer, a differential-mode inductor transformer, a first capacitor, a second capacitor, and a damping resistor. The output terminal of the common-mode inductor transformer is connected to the differential-mode inductor transformer. The output terminal of the differential-mode inductor transformer is connected to one end of the first capacitor. The other end of the first capacitor is connected in series with one end of the second capacitor. The other end of the second capacitor is connected to the damping resistor and finally connected to the AN7581 terminal.

2. The device for implementing Gigabit Ethernet ports to meet EMC lightning strike testing based on the AN7581 scheme according to claim 1, characterized in that, The common-mode inductor transformer filters out noise signals, the differential-mode inductor transformer buffers the signal, rectifies the current, and filters out AC signals, the first capacitor isolates DC voltage, the second capacitor provides secondary isolation of DC voltage, and the damping resistor absorbs the remaining signal and performs rectification and voltage regulation.

3. The device for implementing Gigabit Ethernet ports to meet EMC lightning strike testing based on the AN7581 scheme according to claim 1, characterized in that, The device also includes a reserved third capacitor, one end of which is connected to a damping resistor, and the other end of which is grounded.

4. The device for implementing Gigabit Ethernet ports to meet EMC lightning strike testing based on the AN7581 scheme according to claim 3, characterized in that, The third capacitor filters and absorbs the signal.

5. The device for implementing Gigabit Ethernet ports to meet EMC lightning strike testing based on the AN7581 scheme according to claim 1, characterized in that, The capacitance values ​​of the first and second capacitors are 0.1uF.

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