CN210536290U - Vehicle-mounted Ethernet interface filtering protection circuit - Google Patents

Abstract

The utility model provides a vehicle-mounted Ethernet interface filter protection circuit is applied to between vehicle-mounted Ethernet bus network and the vehicle-mounted Ethernet physical layer controller, and this filter protection circuit includes: the electrostatic surge protection module is connected with the vehicle-mounted Ethernet bus network and is used for filtering interference signals including static electricity and surge on the bus; the coupling module is connected with the electrostatic surge protection module and is used for isolating the direct current signal to prevent the harmful direct current signal from interfering the bus; the common-mode filtering module is connected with the coupling module and is used for filtering common-mode signals on the bus; and the multi-stage high-frequency filtering and multi-stage differential mode filtering modules are respectively connected with the common mode filtering module and the vehicle-mounted Ethernet physical layer controller and are used for filtering high-frequency clutter and differential mode signals on the bus. The utility model provides a scheme harmful voltage such as static, surge on the filtering vehicle bus that can be fine protects the safety of self system to can guarantee bus data's collection accuracy.

Description

Vehicle-mounted Ethernet interface filtering protection circuit

Technical Field

The utility model relates to a car networking technical field especially relates to a vehicle-mounted Ethernet interface filter protection circuit.

Background

The rapid development of automobile technology, the low rate of the traditional vehicle-mounted bus cannot meet the requirement, the vehicle-mounted ethernet begins to become a vehicle-mounted backbone network, the electronic system on the vehicle is very complex, the generator and some inductive loads exist, the generator and the inductive loads can cause the vehicle-mounted power supply system to have very unstable voltage, when the power supply signal passes through the vehicle-mounted ethernet bus, a plurality of interference signals such as static electricity, surge and the like are mixed on the vehicle-mounted ethernet bus, if the interface circuit of the vehicle-mounted ethernet bus is not ideal, the acquired information is inaccurate, or the static electricity and the surge can not be filtered, and the interference signals such as the static electricity and the surge can seriously affect the working reliability and the safety of the vehicle-mounted electronic system when the vehicle-mounted power supply system is used for supplying power to the vehicle-. The vehicle-mounted electronic system includes, but is not limited to, a vehicle audio system, a navigation system, a car information system, and the like.

Therefore, it is desirable to provide a vehicle-mounted ethernet interface protection circuit that can filter harmful voltages such as static electricity and surge on a vehicle-mounted ethernet bus well, protect the safety of a vehicle-mounted electronic system, and ensure the accuracy of acquired information.

SUMMERY OF THE UTILITY MODEL

In view of the above technical problem, the present invention has been made in order to provide an on-vehicle ethernet interface filter protection circuit that overcomes or at least partially solves the above problems.

The foundation the utility model discloses an aspect provides a vehicle-mounted ethernet interface filter protection circuit, is applied to between vehicle-mounted ethernet bus network and the vehicle-mounted ethernet physical layer controller, filter protection circuit includes:

the electrostatic surge protection module is connected with the vehicle-mounted Ethernet bus network and is configured for filtering interference signals including static electricity and surge on the bus;

the coupling module is connected with the electrostatic surge protection module and is configured for isolating direct current signals to prevent harmful direct current signals from interfering a bus;

the common-mode filtering module is connected with the coupling module and is configured for filtering common-mode signals on a bus;

and the multi-stage high-frequency filtering and multi-stage differential mode filtering module is respectively connected with the common-mode filtering module and the vehicle-mounted Ethernet physical layer controller and is configured for filtering high-frequency clutter and differential mode signals on a bus.

Optionally, the electrostatic surge protection module includes:

a first TVS diode D1 connected between the negative terminal of the bus and a first ground terminal;

a second TVS diode D2 connected between the positive electrode of the bus and a first ground terminal;

the coupling module includes:

a first capacitor C1 disposed on the negative electrode of the bus;

a second capacitor C2 disposed on the positive pole of the bus.

Optionally, the common mode filtering module comprises a common mode inductor Lg, wherein

The common-mode inductor Lg comprises two common-mode inductor coils which are respectively arranged on the anode and the cathode of the bus.

Optionally, the multistage high-frequency filtering and multistage differential-mode filtering module includes a first-stage high-frequency filtering unit, a first-stage differential-mode filtering unit, a second-stage high-frequency filtering unit, a second-stage differential-mode filtering unit, and a third-stage high-frequency filtering unit, which are connected in sequence; and is

The first-level high-frequency filtering unit is connected with the common-mode filtering module, and the third-level high-frequency filtering unit is connected with the vehicle-mounted Ethernet physical layer controller.

Optionally, the first-stage high-frequency filtering unit comprises a first resistor R1, a third capacitor C3, a second resistor R2 and a fourth capacitor C4; wherein the content of the first and second substances,

the first resistor R1 is connected in series with the third capacitor C3 and is connected between the negative pole of the bus and the second grounding end after being connected in series;

the second resistor R2 is connected in series with the fourth capacitor C4, and is connected between the positive terminal of the bus and the second ground terminal after the series connection.

Optionally, the primary differential-mode filtering unit includes a first inductor L1, a third resistor R3, a second inductor L2, and a fourth resistor R4; wherein

The first inductor L1 and the third resistor R3 are arranged on the negative electrode of the bus in series;

the second inductor L2 and the fourth resistor R4 are arranged in series on the positive pole of the bus.

Optionally, the two-stage high-frequency filtering unit comprises a fifth resistor R5, a fifth capacitor C5, a sixth resistor R6, a seventh resistor R7, a sixth capacitor C6 and an eighth resistor R8; wherein the content of the first and second substances,

the fifth resistor R5 is connected in series with the fifth capacitor C5, and is connected between the negative electrode of the bus and the second ground after being connected in series, and the sixth resistor R6 is connected in parallel with the fifth capacitor C5;

the seventh resistor R7 is connected in series with the sixth capacitor C6, and is connected between the positive electrode of the bus and the second ground after being connected in series, and the eighth resistor R8 is connected in parallel with the sixth capacitor C6.

Optionally, the two-stage differential mode filtering unit includes a third inductor L3, a ninth resistor R9, a fourth inductor L4, and a tenth resistor R10; wherein the content of the first and second substances,

the third inductor L3 and the ninth resistor R9 are serially disposed on the positive pole of the bus, and the fourth inductor L4 and the tenth resistor R10 are serially disposed on the negative pole of the bus.

Optionally, the three-stage high-frequency filtering unit comprises an eleventh resistor R11, a seventh capacitor C7, a twelfth resistor R12 and an eighth capacitor C8; wherein the content of the first and second substances,

the eleventh resistor R11 is connected in series with the seventh capacitor C7 and is connected between the negative electrode of the bus and the second grounding end after being connected in series;

the twelfth resistor R12 is connected in series with the eighth capacitor C8, and is connected between the positive electrode of the bus and the second ground after being connected in series.

Optionally, the waterproof device for a PCBA of the vehicle-mounted sensor further includes:

the input/output ground dividing module is configured to divide a ground wire in the vehicle-mounted Ethernet bus into a first ground terminal and a second ground terminal, wherein the first ground terminal is a ground terminal of the bus input end, and the second ground terminal is a ground terminal of the bus output end;

the input/output ground dividing module includes a thirteenth resistor R13 connected between the first ground terminal and the second ground terminal.

The utility model provides a vehicle-mounted Ethernet interface filter protection circuit is applied to between vehicle-mounted Ethernet bus network and the vehicle-mounted Ethernet physical layer controller, the utility model provides a technical scheme through the interference signal including static, surge on the static surge protection module filtering bus, keeps apart direct current signal in order to prevent harmful direct current signal interference bus through coupling module, through the common mode signal on the common mode filtering module filtering bus, through high frequency clutter and the differential mode signal on multistage high frequency filtering and the multistage differential mode filtering module filtering bus. Based on the utility model provides a scheme can guarantee that clutter signal and interference signal on the signal path obtain fine filtering to there is fine guard action to the mobile unit, make the signal on the bus remain stable, on-vehicle ethernet physical layer controller can obtain clean stable bus signal, thereby has guaranteed the stability and the reliability of signal identification collection, has guaranteed that the application that the mobile unit can be fine is in on-vehicle complicated electrical environment.

Further, the utility model discloses an input/output ground is cut apart the module and can be split into first earthing terminal and second earthing terminal with the ground wire in the on-vehicle ethernet bus, because input/output ground is cut apart the module and is included thirteenth resistance R3, it is connected between first earthing terminal and second earthing terminal, make the input/output ground wire cut apart, single-point ground's effect has been realized from this, the unclean ground signal of on-vehicle ethernet bus network input has been avoided, direct conduction is to whole on-vehicle electronic system ground signal plane, form ground noise, thereby improve on-vehicle electronic system's interference killing feature.

The above description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented according to the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more obvious and understandable, the following detailed description of the present invention is given.

The above and other objects, advantages and features of the present invention will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present invention will be described in detail hereinafter, by way of illustration and not by way of limitation, with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

fig. 1 shows a schematic diagram of a filtering protection circuit of a vehicle-mounted ethernet interface according to an embodiment of the present invention;

fig. 2 shows a schematic diagram of a vehicle ethernet interface filter protection circuit according to another embodiment of the present invention;

fig. 3 shows a schematic circuit diagram of an input/output division module according to an embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It should be noted that the features of the embodiments and preferred embodiments of the present invention can be combined without conflict.

Fig. 1 shows a schematic diagram of a filtering protection circuit of an on-vehicle ethernet interface according to an embodiment of the present invention. As shown in fig. 1, the embodiment of the present invention provides a vehicle ethernet interface filter protection circuit 300, which is applied between a vehicle ethernet bus network 100 and a vehicle ethernet physical layer controller 200.

The vehicle ethernet bus network is also known as an on-board bus, which has a positive P + and a negative N-, and the vehicle ethernet Physical layer (PHY) controller is also known as a vehicle ethernet PHY controller, which also has a positive PHY _ P and a negative PHY _ N. The filter protection circuit 300 is composed of a circuit on a bus anode P + and a circuit on a bus cathode N-, two ends of the circuit on the bus anode P + are respectively connected with the bus anode P + and an anode PHY _ P of the vehicle-mounted Ethernet PHY controller, and the circuit on the bus cathode N-is respectively connected with a bus cathode N-and a cathode PHY _ N of the vehicle-mounted Ethernet PHY controller.

In this embodiment, the filter protection circuit 300 includes an electrostatic surge protection module 310, a coupling module 320, a common mode filtering module 330, and a multi-stage high frequency filtering and multi-stage differential mode filtering module 340. The electrostatic surge protection module 310 is connected to the vehicle-mounted ethernet bus network 100 and configured to filter interference signals on the bus, such as static electricity and surge, the coupling module 320 is connected to the electrostatic surge protection module 310 and configured to isolate a dc signal to prevent a harmful dc signal from interfering with the bus, the common mode filtering module 330 is connected to the coupling module 320 and configured to filter a common mode signal on the bus, and the multi-stage high frequency filtering and multi-stage differential mode filtering module 340 is connected to the common mode filtering module 330 and the vehicle-mounted ethernet PHY controller 200, and configured to filter a high frequency clutter and a differential mode signal on the bus.

The embodiment of the utility model provides a vehicle-mounted Ethernet interface filter protection circuit can be applied to between vehicle-mounted Ethernet bus network and the vehicle-mounted Ethernet PHY controller, including static on the module filtering bus of static surge protection, the interference signal of surge, keep apart direct current signal through the coupling module in order to prevent harmful direct current signal interference bus, through the common mode signal on the module filtering bus of common mode filtering, through high frequency clutter and the differential mode signal on multistage high frequency filter and the multistage differential mode filtering module filtering bus. The design that so adopts a plurality of module circuits can guarantee that clutter signal and interference signal on the signal path obtain fine filtering to there is fine guard action to the mobile unit, make the signal on the bus remain stable, on-vehicle ethernet PHY controller can obtain clean stable bus signal, thereby has guaranteed the stability and the reliability of signal identification collection, has guaranteed that the mobile unit can be fine uses in on-vehicle complicated electrical environment.

The vehicle-mounted device includes, for example, electronic devices such as a vehicle-mounted sound box, a vehicle-mounted television, a vehicle-mounted air conditioner, an intelligent rearview mirror, a reversing radar, a vehicle-mounted navigation system, and a vehicle-mounted WIFI device.

Fig. 2 shows a schematic diagram of a filtering protection circuit of an on-vehicle ethernet interface according to another embodiment of the present invention. As shown in fig. 2, the esd protection module 310 may include a first TVS diode (TVS diode) D1 and a second TVS diode D2, wherein the first TVS diode D1 is connected between the negative electrode N-of the bus and the first ground terminal, and the second TVS diode D2 is connected between the positive electrode P + of the bus and the first ground terminal.

The first ground terminal refers to an analog signal ground terminal (e.g., the analog signal ground terminal AGND schematically shown in fig. 2), that is, a ground terminal of the bus input terminal.

In this embodiment, the electrostatic surge protection module 310 is composed of a first TVS diode D1 and a second TVS diode D2, and is mainly responsible for filtering out the very harmful interference signals such as static electricity and surge on the bus.

In a preferred embodiment of the present invention, the first TVS diode D1 and the second TVS diode D2 can be made of Littelfuse car-size device product, the model is AXGD10402KR, the car-size device AXGD10402KR can load 30KV contact/air discharge, and it has an ultra-low parasitic capacitance of 0.04pf, and the influence on the ethernet bus signal is very small.

With continued reference to fig. 2, in an embodiment of the present invention, the coupling module 320 may adopt an ac coupling circuit design, and on the premise of ac coupling, the coupling module 320 includes a first capacitor C1 and a second capacitor C2, wherein the first capacitor C1 is disposed on the negative electrode N-of the bus, and the second capacitor C2 is disposed on the positive electrode P + of the bus. The capacitance value of the first capacitor C1 and the capacitance value of the second capacitor C2 are preferably 0.1 muF.

In the embodiment, the two capacitors are used for forming an alternating current coupling circuit to isolate direct current signals on the bus, so that harmful direct current signals are prevented from interfering with the bus and influencing signal identification and acquisition. Therefore, the stability and reliability of signal identification and acquisition can be ensured.

The common mode signal is a main cause of an Electromagnetic Interference (EMI) problem, which may cause a very serious EMI problem, and a common mode filter circuit may be used in the circuit to filter the common mode signal on the bus and ensure the EMI performance of the device. With continued reference to fig. 2, in an embodiment of the present invention, the common mode filtering module 330 may include a common mode inductor Lg, wherein the common mode inductor includes two common mode inductor coils, which are respectively disposed on the positive electrode P + and the negative electrode N-of the bus.

Optionally, the common mode inductor Lg is a common mode inductor of model ACT1210L-101-2P-TL00, which is manufactured by TDK corporation, and has a resistance value of preferably 100 μ F, a maximum direct current of preferably 150mA, and an impedance of preferably 3700 Ohm.

Continuing to refer to fig. 2, in an embodiment of the present invention, the multistage high frequency filtering and multistage differential mode filtering module 340 may include a first-stage high frequency filtering unit 341, a first-stage differential mode filtering unit 342, a second-stage high frequency filtering unit 343, a second-stage differential mode filtering unit 344 and a third-stage high frequency filtering unit 345 connected in sequence, and in this embodiment, the first-stage high frequency filtering unit 341 is connected with the common mode filtering module 330, and the third-stage high frequency filtering unit 345 is connected with the vehicle-mounted ethernet PHY controller 200.

This embodiment can effectively filter the high frequency clutter on the bus through many times of high frequency filtering to guarantee bus signal's stability, can effectively filter the difference mode signal on the bus through many times of difference mode filtering, thereby further guarantee the stability of signal on the bus. Because the differential mode signal can also cause the problem of serious electromagnetic interference (EMI), the adoption of the differential mode signal for multiple times can also ensure the EMI performance of the equipment.

With continued reference to fig. 2, in an embodiment of the present invention, the first-stage high-frequency filtering unit 341 may include a first resistor R1, a third capacitor C3, a second resistor R2, and a fourth capacitor C4. The first resistor R1 is connected in series with the third capacitor C3 and then connected between the negative N-of the bus and the second ground, and the second resistor R2 is connected in series with the fourth capacitor C4 and then connected between the positive P + of the bus and the second ground.

The second ground terminal refers to a common ground terminal (such as the common ground terminal GND shown schematically in fig. 2), that is, a ground terminal of the bus output terminal.

In this embodiment, the circuit portion on the negative electrode N-of the bus is composed of the first resistor R1 and the third capacitor C3, the circuit portion on the positive electrode P + of the bus is composed of the second resistor R2 and the fourth capacitor C4, the third capacitor C3 and the fourth capacitor C4 can be used for providing a signal path, and the first resistor R1 and the second resistor R2 can absorb the energy of the high-frequency noise signal, so that the high-frequency noise on the bus is filtered once, and the stability of the bus signal is improved.

Preferably, the resistances of the first resistor R1 and the second resistor R2 are 40.2 Ω, respectively, with an error of ± 1%, and the capacitances of the third capacitor C3 and the fourth capacitor C3 are 2.7 pF.

With continued reference to fig. 2, in an embodiment of the present invention, the first-stage differential mode filtering unit 342 may include a first inductor L1, a third resistor R3, a second inductor L2, and a fourth resistor R4. The first inductor L1 and the third resistor R3 are arranged on the negative pole N-of the bus in series, and the second inductor L2 and the fourth resistor R4 are arranged on the positive pole P + of the bus in series.

In this embodiment, the circuit portion on the negative electrode N-of the bus is composed of the first inductor L1 and the third resistor R3, the circuit portion on the positive electrode P + of the bus is composed of the second inductor L2 and the fourth resistor R4, the third resistor R3 and the fourth resistor R4 are used for providing buffering of a signal path, the first inductor L1 and the second inductor L2 filter ripple waves and differential mode signals on the bus at one time, and therefore stability of the signals and electromagnetic interference EMI performance of the device are guaranteed.

Preferably, the inductance resistance values of the first inductor L1 and the second inductor L2 are 6.8nH, respectively, and the error of the inductance resistance values is ± 2%, and the resistance values of the third resistor R3 and the fourth resistor R3 are 1 Ω, respectively, and the error is ± 1%.

With continued reference to fig. 2, in an embodiment of the present invention, the two-stage high-frequency filtering unit 343 may include a fifth resistor R5, a fifth capacitor C5, a sixth resistor R6, a seventh resistor R7, a sixth capacitor C6, and an eighth resistor R8. The fifth resistor R5 is connected in series with the fifth capacitor C5, and is connected between the negative electrode N-of the bus and the second ground after being connected in series, and the sixth resistor R6 is connected in parallel with the fifth capacitor C5. The seventh resistor R7 is connected in series with the sixth capacitor C6, and is connected between the positive electrode P + of the bus and the second ground after being connected in series, and the eighth resistor R8 is connected in parallel with the sixth capacitor C6.

In this embodiment, the circuit portion on the negative electrode N-of the bus is composed of a fifth resistor R5, a fifth capacitor C5 and a sixth resistor R6, the circuit portion on the positive electrode P + of the bus is composed of a seventh resistor R7, a sixth capacitor C6 and an eighth resistor R8, the fifth capacitor C5 and the sixth capacitor C6 can be used for providing a signal path, and the fifth resistor R5, the sixth resistor R6, the seventh resistor R7 and the eighth resistor R8 can be used for absorbing energy of high-frequency noise signals, so that high-frequency noise on the bus is filtered for the second time, and stability of the bus signals is further improved.

Preferably, the resistance values of the fifth resistor R5 and the seventh resistor R7 are 330 Ω, respectively, and the tolerance of the resistance values is ± 5%, the resistance values of the sixth resistor R6 and the eighth resistor R8 are 510 Ω, respectively, and the tolerance of the resistance values is ± 1%, and the capacitance values of the fifth capacitor C5 and the sixth capacitor C6 are 2.7pF, respectively.

With continued reference to fig. 2, in an embodiment of the present invention, the second-stage differential mode filtering unit 344 may include a third inductor L3, a ninth resistor R9, a fourth inductor L4, and a tenth resistor R10. The third inductor L3 and the ninth resistor R9 are serially connected to the positive electrode P + of the bus, and the fourth inductor L4 and the tenth resistor R10 are serially connected to the negative electrode N-of the bus.

In this embodiment, the circuit portion on the negative electrode N-of the bus is composed of a third inductor L3 and a ninth resistor R9, the circuit portion on the positive electrode P + of the bus is composed of a fourth inductor L4 and a tenth resistor R10, the ninth resistor R9 and the tenth resistor R10 are used for providing buffering of a signal path, and the third inductor L3 and the fourth inductor L4 are used for filtering ripple waves and differential mode signals on the bus for a second time, so that the stability of signals on the bus is further ensured, and the electromagnetic interference EMI performance of the device is further ensured.

Preferably, the resistance values of the ninth resistor R9 and the tenth resistor R10 are 1 Ω, the tolerance of the resistance values is ± 1%, and the inductance values of the third inductor L3 and the fourth inductor L4 are 6.8nH, respectively.

With continued reference to fig. 2, in an embodiment of the present invention, the three-stage high frequency filtering unit 345 may include an eleventh resistor R11, a seventh capacitor C7, a twelfth resistor R12, and an eighth capacitor C8. The eleventh resistor R11 is connected in series with the seventh capacitor C7 and connected between the negative electrode N-of the bus and the second ground terminal, and the twelfth resistor R12 is connected in series with the eighth capacitor C8 and connected between the positive electrode P + of the bus and the second ground terminal.

In this embodiment, the circuit portion on the negative electrode N-of the bus is composed of an eleventh resistor R11 and a seventh capacitor C7, the circuit portion on the positive electrode P + of the bus is composed of a twelfth resistor R12 and an eighth capacitor C8, the seventh capacitor C7 and the eighth capacitor C8 are used for providing a signal path, and the eleventh resistor R11 and the twelfth resistor R12 are used for absorbing energy of high-frequency noise on the bus, so as to filter the high-frequency noise on the bus three times, further ensure the cleanness and stability of the bus signal, further ensure that the ethernet bus signal received by the ethernet PHY controller on the device is clean and stable, and thus ensure the operation stability of the device.

Preferably, the resistance values of the eleventh resistor R11 and the twelfth resistor R12 are 40.2 Ω, respectively, the tolerance of the resistance values is ± 1%, and the capacitance values of the seventh capacitor C7 and the eighth capacitor C8 are 2.7pF, respectively.

Fig. 3 shows a schematic diagram of an input/output division module according to an embodiment of the present invention. As shown in fig. 3, the filter protection circuit 300 may further include an input/output ground dividing module 350, configured to divide a ground line in the vehicle ethernet bus into a first ground terminal and a second ground terminal. The ground connected to the connector end of the on-vehicle ethernet bus network 100 is the first ground end and also the analog signal ground end AGND, where the connector is disposed at the interface at the end of the bus for transmitting current or signals. The discharged ground of the electrostatic surge protection module 310 is also the first ground, and the discharged ground is the ground for electrostatic discharge and surge discharge.

The second ground terminal is a ground terminal of the whole filter protection circuit system, that is, a common ground terminal GND. In other words, the first ground is a ground of the bus input terminal, and the second ground is a ground of the bus output terminal.

As shown in fig. 3, the i/o ground division block 350 may include a thirteenth resistor R13, wherein the thirteenth resistor R13 is connected between the first ground and the second ground, so as to divide the ground of the bus input and output terminals.

The resistance value of the thirteenth resistor R13 is very small, close to 0 Ω, but not equal to 0 Ω, and preferably, the resistance value of the thirteenth resistor R13 has a tolerance of ± 5%.

In this embodiment, the thirteenth resistor R13 with a small resistance is connected between the first ground terminal and the second ground terminal, so that the ground lines of the ground terminal of the bus input terminal and the ground terminal of the bus output terminal are divided, thereby achieving the effect of single-point grounding, preventing the unclean ground signal (i.e., the ground signal containing the interference signals such as static electricity and surge) at the bus network input terminal of the vehicle-mounted ethernet network from being directly conducted to the ground signal plane of the whole vehicle-mounted electronic system to form ground noise, and improving the anti-interference capability of the vehicle-mounted electronic system.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments can be modified or some or all of the technical features can be equivalently replaced within the spirit and principles of the present invention; such modifications or substitutions do not depart from the scope of the present invention.

Claims (10)

1. A vehicle Ethernet interface filter protection circuit is applied between a vehicle Ethernet bus network and a vehicle Ethernet physical layer controller, and is characterized by comprising:

the electrostatic surge protection module is connected with the vehicle-mounted Ethernet bus network and is configured for filtering interference signals including static electricity and surge on the bus;

the coupling module is connected with the electrostatic surge protection module and is configured for isolating direct current signals to prevent harmful direct current signals from interfering a bus;

the common-mode filtering module is connected with the coupling module and is configured for filtering common-mode signals on a bus;

and the multi-stage high-frequency filtering and multi-stage differential mode filtering module is respectively connected with the common-mode filtering module and the vehicle-mounted Ethernet physical layer controller and is configured for filtering high-frequency clutter and differential mode signals on a bus.

2. The vehicle-mounted ethernet interface filter protection circuit according to claim 1, wherein said electrostatic surge protection module comprises:

a first TVS diode D1 connected between the negative terminal of the bus and a first ground terminal;

a second TVS diode D2 connected between the positive electrode of the bus and a first ground terminal;

the coupling module includes:

a first capacitor C1 disposed on the negative electrode of the bus;

a second capacitor C2 disposed on the positive pole of the bus.

3. The on-board Ethernet interface filter protection circuit of claim 1, wherein the common mode filter module comprises a common mode inductor Lg, wherein,

the common-mode inductor Lg comprises two common-mode inductor coils which are respectively arranged on the anode and the cathode of the bus.

4. The vehicle-mounted Ethernet interface filtering protection circuit according to any one of claims 1 to 3, wherein the multistage high-frequency filtering and multistage differential mode filtering module comprises a first-stage high-frequency filtering unit, a first-stage differential mode filtering unit, a second-stage high-frequency filtering unit, a second-stage differential mode filtering unit and a third-stage high-frequency filtering unit which are connected in sequence; and is

The first-level high-frequency filtering unit is connected with the common-mode filtering module, and the third-level high-frequency filtering unit is connected with the vehicle-mounted Ethernet physical layer controller.

5. The vehicle-mounted Ethernet interface filter protection circuit of claim 4, wherein the primary high frequency filter unit comprises a first resistor R1, a third capacitor C3, a second resistor R2, a fourth capacitor C4; wherein the content of the first and second substances,

the first resistor R1 is connected in series with the third capacitor C3 and is connected between the negative pole of the bus and the second grounding end after being connected in series;

the second resistor R2 is connected in series with the fourth capacitor C4, and is connected between the positive terminal of the bus and the second ground terminal after the series connection.

6. The vehicle-mounted Ethernet interface filter protection circuit of claim 4, wherein the primary differential mode filter unit comprises a first inductor L1, a third resistor R3, a second inductor L2, and a fourth resistor R4; wherein the content of the first and second substances,

the first inductor L1 and the third resistor R3 are arranged on the negative electrode of the bus in series;

the second inductor L2 and the fourth resistor R4 are arranged in series on the positive pole of the bus.

7. The vehicle-mounted Ethernet interface filter protection circuit of claim 4, wherein the two-stage high frequency filter unit comprises a fifth resistor R5, a fifth capacitor C5, a sixth resistor R6, a seventh resistor R7, a sixth capacitor C6, an eighth resistor R8; wherein the content of the first and second substances,

the fifth resistor R5 is connected in series with the fifth capacitor C5, and is connected between the negative electrode of the bus and the second ground after being connected in series, and the sixth resistor R6 is connected in parallel with the fifth capacitor C5;

the seventh resistor R7 is connected in series with the sixth capacitor C6, and is connected between the positive electrode of the bus and the second ground after being connected in series, and the eighth resistor R8 is connected in parallel with the sixth capacitor C6.

8. The vehicle-mounted Ethernet interface filtering protection circuit of claim 4, wherein the two-stage differential mode filtering unit comprises a third inductor L3, a ninth resistor R9, a fourth inductor L4 and a tenth resistor R10; wherein the content of the first and second substances,

the third inductor L3 and the ninth resistor R9 are serially disposed on the positive pole of the bus, and the fourth inductor L4 and the tenth resistor R10 are serially disposed on the negative pole of the bus.

9. The vehicle Ethernet interface filter protection circuit of claim 4, wherein the three-stage high frequency filtering unit comprises an eleventh resistor R11, a seventh capacitor C7, a twelfth resistor R12, an eighth capacitor C8; wherein the content of the first and second substances,

the eleventh resistor R11 is connected in series with the seventh capacitor C7 and is connected between the negative electrode of the bus and the second grounding end after being connected in series;

the twelfth resistor R12 is connected in series with the eighth capacitor C8, and is connected between the positive electrode of the bus and the second ground after being connected in series.

10. The on-board ethernet interface filter protection circuit of claim 1, further comprising:

the input/output ground dividing module is configured to divide a ground wire in the vehicle-mounted Ethernet bus into a first ground terminal and a second ground terminal, wherein the first ground terminal is a ground terminal of the bus input end, and the second ground terminal is a ground terminal of the bus output end;

the input/output ground dividing module includes a thirteenth resistor R13 connected between the first ground terminal and the second ground terminal.

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