CN215818181U

CN215818181U - Ethernet transmission circuit

Info

Publication number: CN215818181U
Application number: CN202122285735.1U
Authority: CN
Inventors: 莫敏宁
Original assignee: Shenzhen Kunci Technology Co ltd
Current assignee: Shenzhen Kunci Technology Co ltd
Priority date: 2021-09-22
Filing date: 2021-09-22
Publication date: 2022-02-11
Anticipated expiration: 2031-09-22

Abstract

The application discloses an Ethernet transmission circuit, which comprises four groups of sub-circuits, wherein each group of sub-circuits is coupled between an Ethernet physical layer device and an Ethernet connector. Each set of the sub-circuits includes a differential mode inductor coupled to a first input terminal and a second input terminal of the sub-circuit, a first capacitor coupled to the first input terminal and the differential mode inductor, a second capacitor coupled to the second input terminal and the differential mode inductor, a common mode inductor coupled to the first capacitor and the second capacitor, and a diode bridge coupled to the common mode inductor.

Description

Ethernet transmission circuit

Technical Field

The utility model relates to an Ethernet transmission circuit. Specifically, the ethernet transmission circuit of the present invention can provide signal coupling, dc isolation and surge protection functions for ethernet transmission, thereby replacing the conventional ethernet transformer.

Background

The conventional ethernet transformer can achieve the effects of signal isolation, signal coupling, and common-mode filtering for the input signals of the ethernet. However, conventional ethernet transformers do not have surge protection (also called surge protection) functions, so that conventional ethernet transmission circuits often fail to operate effectively in environments that are susceptible to surges (e.g., lightning strikes, static electricity, or switching from a power source to other loads in the circuit). In view of the above, how to provide an ethernet transmission circuit with a surge protection function in addition to basic signal coupling and dc isolation functions is a problem to be solved in the art.

SUMMERY OF THE UTILITY MODEL

In order to solve at least the above problems, the present invention discloses an ethernet transmission circuit. The ethernet transport circuit includes four sets of sub-circuits, and each set of sub-circuits is coupled between an ethernet physical layer device and an ethernet connector. Each set of the sub-circuits includes a differential mode inductor, a common mode inductor, a first capacitor, a second capacitor, and a diode bridge. The differential mode inductor is coupled to the first input terminal and the second input terminal of the sub-circuit. The first capacitor is coupled to the first input terminal and the differential mode inductor. The second capacitor is coupled to the second input terminal and the differential mode inductor. The common mode inductor is coupled to the first capacitor and the second capacitor. The diode bridge is coupled to the common mode inductor.

The main objects, technical means and embodiments of the present invention will be understood by those skilled in the art after referring to the accompanying drawings and the embodiments described later.

Drawings

The utility model is described in further detail below with reference to the accompanying drawings and the detailed description, wherein fig. 1 is a schematic diagram of an implementation of the ethernet transmission circuit of the utility model.

Detailed Description

The following examples are provided to illustrate the technical content of the present invention and are not intended to limit the scope of the present invention. It should be noted that in the following embodiments and the accompanying drawings, elements irrelevant to the present invention are omitted and not shown, and the dimensional relationship between the elements in the drawings is only for easy understanding and is not intended to limit the actual scale.

Fig. 1 is a schematic diagram of an embodiment of an ethernet transmission circuit of the present invention. Referring to fig. 1, the ethernet transmission circuit 1 may basically include four sets of

sub-circuits

11, 12, 13, 14, and may be coupled to a signal source of the ethernet (e.g., a Physical (PHY) layer device in the ethernet). Since eight signals of the ethernet signal source can be equally divided into four groups of signals, the

sub-circuits

11, 12, 13, 14 can respectively correspond to one of the four groups of signals of the ethernet signal source. The

sub-circuits

11, 12, 13, 14 have substantially the same structure and the input and output types of the respective couplings are similar. Therefore, based on the principle of simplifying the description, only the sub-circuit 11 is taken as an example for illustration, but those skilled in the art can understand the corresponding structures, functions and parameters/set values applicable to each component in the

sub-circuits

12, 13, 14 according to the description of the sub-circuit 11.

A set of ethernet signals processed by the sub-circuit 11 may be output from the output terminal OUT11 and the output terminal OUT12 to the ethernet connector. The ethernet connector may be an ethernet connector with an RJ-45 or 8P8C interface. Since the

sub-circuits

12, 13, 14 and the sub-circuit 11 have substantially the same structure, a person skilled in the art can understand how the

sub-circuits

12, 13, 14 output the processed three sets of ethernet signals to the ethernet connector in the same manner as the sub-circuit 11 according to the description of the sub-circuit 11, and the details of the same are not repeated herein.

The sub-circuit 11 may include a differential mode inductor DM11, a common mode inductor DM12, a capacitor C11, a capacitor C12, and a diode bridge DB 1. The differential mode inductor DM11 and the two inputs IN11 and IN12 of the sub-circuit 11 may be coupled to two connection points P1 and P2, respectively, so that a set of differential mode signals received from the inputs IN11 and IN12 of the ethernet network may be coupled asymmetrically with respect to the core among the four terminals IN the differential mode inductor DM11, respectively.

The capacitor C11 may be coupled to the input terminal IN11 and the differential mode inductor DM 11. More specifically, the capacitor C11 may be coupled at the connection point P1. Similarly, a capacitor C12 may be coupled to the input terminal IN12 and the differential mode inductor DM 11. More specifically, the capacitor C11 may be coupled at the connection point P2. The capacitor C11 and the capacitor C12 may be used to provide dc isolation and signal coupling functions for the sub-circuit 11. In some embodiments, the capacitance of the capacitor C11 and the capacitance of the capacitor C12 may be between 50 nanofarads and 1 microfarads.

The common mode inductor DM12 may be coupled to a capacitor C11 and a capacitor C12. More specifically, the capacitor C11 and the capacitor C12 may be coupled to two terminals of the four terminals of the common mode inductor DM12 that are symmetrical with respect to the magnetic core. Common mode inductor DM12 may be used to provide a common mode filtering effect for high frequencies. In some embodiments, the inductance value of common mode inductor DM12 may be between 10 nanohenries (nH) to 5 microhenries (uH).

The diode bridge DB1 can be coupled to two output terminals of the common mode inductor DM12, that is, two signal outputs of the common mode inductor DM12 can be coupled to two input terminals P3 and P4 of the diode bridge DB1, respectively. The input node P3 and the node P4 may be coupled to two output terminals OUT11 and OUT12 of the sub-circuit 11, respectively.

In some embodiments, the ethernet transmission circuit 1 may further comprise an inductor L1 and an inductor L2. The positive output terminal of diode bridge DB1 and the positive output terminal of the corresponding diode bridge in

sub-circuits

12, 13, 14 can be coupled to inductor L1. The negative output terminal of diode bridge DB1 and the negative output terminal of the corresponding diode bridge in

sub-circuits

12, 13, 14 can be coupled to inductor L2. Both inductor L1 and inductor L2 may be coupled to ground G1. In some embodiments, ground G1 may be in the form of a chassis ground (chassis ground).

The combination of diode bridges and inductors L1 and L2 in the

sub-circuits

11, 12, 13, 14 can provide common mode protection and impedance matching effects for the ethernet transmission circuit 1. By adjusting the inductance values of inductor L1 and inductor L2, the differential mode impedance can be adjusted and cross talk (crosstalk) between the channels is reduced. In certain embodiments, the inductance value of inductor L1 and the inductance value of inductor L2 may be between 10 and 300 microhenries.

In some embodiments, ethernet transmission circuit 1 may further include a specific magnetic core (not shown), and inductor L1 and inductor L2 may be wound around the specific magnetic core to form a differential mode inductor.

In some embodiments, the ethernet transmission circuit 1 may further comprise a capacitor C1. The two signal output terminals of the differential mode inductor in the

sub-circuits

11, 12, 13, 14 may be coupled to the capacitor C1, and the capacitor C1 may be coupled to the ground terminal G2. In some embodiments, the capacitance value of the capacitor C1 may be between 1 nano-farad (nF) and 1 micro-farad (uF).

In some embodiments, individual differential mode inductors (e.g., differential mode inductor DM11) in

subcircuits

11, 12, 13, 14 may be used to provide an external bias path for ethernet transport circuit 1. In this case, each differential mode inductor in the

sub-circuits

11, 12, 13, 14 may be coupled to a voltage source VCC1 through a connection point P5 to provide a bias voltage for the ethernet phy device. At this time, the ethernet physical layer device may be an ethernet physical layer device having a current-driven type ethernet physical layer chip.

In summary, the ethernet transmission circuit 1 of the present invention can provide the functions of signal coupling and dc isolation necessary for ethernet transmission, and can also provide the function of surge protection through its special arrangement. Therefore, the ethernet transmission circuit of the present invention is capable of replacing the conventional ethernet transformer and providing a higher environmental adaptability for ethernet transmission.

The above examples are only intended to illustrate the embodiments of the present invention and to illustrate the technical features of the present invention, and are not intended to limit the scope of the present invention. Any arrangement which can be easily changed or equalized by a person skilled in the art is included in the scope of the present invention, and the scope of the present invention is defined by the appended claims.

Claims

1. Ethernet transmission circuitry, characterized in that said Ethernet transmission circuitry comprises:

four sets of sub-circuits, each set of sub-circuits being coupled between an ethernet physical layer device and an ethernet connector, each set of sub-circuits comprising:

a first differential-mode inductor coupled to the first input terminal and the second input terminal of the sub-circuit;

a first capacitor coupled to the first input terminal and the first differential-mode inductor;

a second capacitor coupled to the second input terminal and the first differential-mode inductor;

a common mode inductor coupled to the first capacitor and the second capacitor; and

a diode bridge coupled to the common mode inductor.

2. The ethernet transport circuit of claim 1, further comprising a first inductor and a second inductor, wherein the first inductor is coupled between a first ground terminal and a positive input terminal of the diode bridge, and the second inductor is coupled between the first ground terminal and a negative input terminal of the diode bridge.

3. The ethernet transport circuit of claim 2, wherein the inductance value of the first inductor and the inductance value of the second inductor are both between 10 microhenries and 300 microhenries.

4. The ethernet transmission circuit of claim 2, wherein the ethernet transmission circuit further comprises a magnetic core, and the first inductor and the second inductor are wound around the magnetic core to form a second differential mode inductor.

5. The ethernet transport circuit of claim 1 further comprising a third capacitor coupled to a second ground terminal and to two signal output terminals of the first differential-mode inductor in each of the sets of sub-circuits.

6. An Ethernet transmission circuit as claimed in claim 5, wherein the capacitance of the third capacitor is between 1 nanofarad and 1 microfarad.

7. An ethernet transmission circuit according to claim 1, wherein the capacitance of said first capacitor and the capacitance of said second capacitor in each of said sets of sub-circuits are both between 50 nanofarads and 1 microfarads.

8. An ethernet transmission circuit according to claim 1, wherein said common mode inductor in each of said sets of sub-circuits has an inductance value between 10 nanohenries and 5 microhenries.

9. The ethernet transport circuit of claim 1, wherein the first differential mode inductor in each of the sets of sub-circuits is coupled to a first voltage source to provide a bias voltage for the ethernet physical layer device.

10. An ethernet transport circuit according to claim 9, wherein said ethernet physical layer device comprises a current-driven ethernet physical layer chip.