TWM634346U - Transmission circuit for ethernet - Google Patents

Abstract

A transmission circuit for Ethernet includes four sub-circuits, a high-voltage capacitor and a first capacitor. The first capacitor is coupled to the ground, and a voltage source. Each sub-circuit is coupled between an Ethernet connection device and an Ethernet PHY device, and includes a transformer, a second capacitor and a third capacitor. The transformer includes two windings, both ends of the first winding being coupled to the Ethernet PHY device, and both ends of the second winding being coupled to the Ethernet connection device. The first winding includes a center tap coupled to the voltage source and the first capacitor. Both the second and third capacitors are coupled to the Ethernet connection device, the second capacitor being coupled between the first end of the second winding and the high-voltage capacitor, and the third capacitor being coupled between the second end of the second winding and the high-voltage capacitor.

Description

transmission circuit for ethernet

The present invention relates to a transmission circuit for the Ethernet. More specifically, the novel Ethernet transmission circuit can replace the traditional Ethernet transformer, and provide functions of signal coupling, DC isolation and surge protection for Ethernet transmission.

Traditionally, network transformers used in Ethernet networks (hereinafter referred to as "Ethernet transformers") use capacitors as the main component for DC isolation (for example: Taiwan Patent No. I533640). Although this method has the advantages of low manufacturing cost and automatic production, the isolation provided by this type of Ethernet transformer between the primary side and the secondary side is only about 10 to 100 volts, which is difficult to meet the high isolation requirements of users. Withstanding voltage (eg: 1000 volts) requirements. In view of this, how to provide an Ethernet transmission circuit capable of providing high isolation and withstand voltage to replace the traditional Ethernet transformer is an urgent problem to be solved in the technical field of the present invention.

In order to solve at least the above problems, the present invention discloses a transmission circuit for Ethernet. The transmission circuit includes a first capacitor, a second capacitor and four transmission sub-circuits. A withstand voltage value of the first capacitor is not lower than 1000V. A first end of the second capacitor is coupled to ground. The second electricity A second end of the capacitor is coupled to a voltage source. Each of the transmission sub-circuits is coupled between an Ethernet connection device and a current-driven Ethernet physical layer device, and is used for transmitting a pair of differential mode signals of the Ethernet. Each of the transmission sub-circuits includes a transformer, a third capacitor and a fourth capacitor. The transformer includes a first winding and a second winding. Two ends of the first winding are coupled to the Ethernet physical layer device, and two ends of the second winding are coupled to the Ethernet connection device. The first winding includes a center tap, and the center tap is coupled to the voltage source and the second capacitor. Both the third capacitor and the fourth capacitor are coupled to the Ethernet connection device, and the third capacitor is coupled between a first end of the second winding and the first capacitor, the fourth capacitor Coupled between a second end of the second winding and the first capacitor.

In order to solve at least the above problems, the present invention also discloses another transmission circuit for Ethernet. The transmission circuit includes four transmission sub-circuits and a first capacitor. A withstand voltage value of the first capacitor is not lower than 1000V. Each of the transmission sub-circuits is coupled between an Ethernet connection device and a voltage-driven Ethernet physical layer device, and is used for transmitting a pair of differential mode signals of the Ethernet. Each of the transmission sub-circuits includes a transformer, a second capacitor and a third capacitor. The transformer includes a first winding and a second winding. Two ends of the first winding are coupled to the Ethernet physical layer device, and two ends of the second winding are coupled to the Ethernet connection device. Both the second capacitor and the third capacitor are coupled to the Ethernet connection device. The second capacitor is coupled between a first end of the second winding and the first capacitor, and the third capacitor is coupled between a second end of the second winding and the first capacitor.

As mentioned above, because the Ethernet transmission circuit of this new type uses the transformer as the main component of DC isolation, and with the special configuration of the components in this new type, the Ethernet transmission circuit The circuit can provide a high isolation withstand voltage such as 1000 volts. Therefore, the novel Ethernet transmission circuit is indeed capable of solving at least the above-mentioned problems in the technical field to which the present disclosure belongs.

The content of the present invention generally describes the core concept of this disclosure, and covers the technical problems to be solved, the technical means to solve the problems and the effects of this disclosure, so as to provide a basic understanding of this disclosure for those with ordinary knowledge in the technical field to which this disclosure belongs . However, it should be understood that this summary is not intended to cover all embodiments of the present disclosure. The following paragraphs will describe various embodiments of the present disclosure along with the drawings.

As follows:

1, 2, 3, 4: transmission circuit

11, 12, 13, 14, 21, 22, 23, 24, 31, 32, 33, 34, 41, 42, 43, 44: transmission sub-circuit

E11, E21: Ethernet physical layer equipment

E12, E22: Ethernet connection equipment

C1, C11, C12, C2: capacitance

CL11, CL12, CL21, CL22: winding

CM1: common mode inductance

G1, G2: ground terminal

T11, T21: transformer

VCC: voltage source

1 to 4 are schematic diagrams of an embodiment of a transmission circuit for an Ethernet network of the present invention.

The embodiments described below are not intended to limit the present invention to any particular environment, application, structure, process or steps described in these embodiments. In the drawings, elements not related to the present invention are not shown. The dimensions and dimensional relationships of the individual elements in the figures are illustrative examples only, and are not intended to limit the invention. In the following description, the same (or similar) reference numerals may correspond to the same (or similar) elements, unless otherwise specified.

The terms used herein are for the purpose of describing the embodiments only and are not intended to limit the present invention. The singular form "a" is also intended to include the plural unless the context clearly dictates otherwise. Terms such as "comprising", "including" and the like specify the presence of stated characters, integers, steps, operations and/or elements, but do not exclude the presence of one or more other characters, integers, steps, operations, elements and/or combinations thereof or add. The term "and/or" includes any and all combinations of one or more of the associated listed items. Although in this paper it is possible Terms such as "first", "second", and "third" are used to describe various elements, but the elements should not be limited by these terms. These terms are only used to distinguish one element from another. Therefore, for example, a first element described below may also be referred to as a second element without departing from the spirit and scope of the present invention.

1-3 are schematic diagrams of an embodiment of the novel Ethernet transmission circuit. More specifically, the novel Ethernet transmission circuit is used to transmit Ethernet signals between an Ethernet physical (PHY) layer device and an Ethernet connection device, and in FIG. 1- In each embodiment of Fig. 3, transmission circuits 1, 2, 3 are used to transmit Ethernet signals between an Ethernet physical layer device E11 and an Ethernet connection device E12, and the Ethernet network The PHY device E11 is a current-driven (ie, includes a current-driven PHY chip) Ethernet PHY device. The Ethernet connection device E12 can be an Ethernet connector with an RJ-45 or 8P8C interface.

Referring first to FIG. 1 . A transmission circuit 1 for Ethernet can basically include four groups of transmission sub-circuits 11, 12, 13, 14 and two capacitors C1 and C2, and can be coupled to the Ethernet physical layer equipment E11 and Ethernet The Ethernet network connects between the devices E12.

The capacitor C1 can be a high voltage capacitor with a capacitance of 1 nanofarad (nF) to 0.1 microfarad (μF). The capacitor C1 can be coupled to a ground terminal G1, and its withstanding voltage can vary according to the isolation desired by the user. For example, the withstand voltage of the capacitor C1 may not be lower than 1000 volts, so as to provide an isolation effect of more than 1000 volts to the ground. In some embodiments, the ground terminal G1 may be in the form of chassis ground.

Capacitor C2 can be a multilayer capacitor for stabilizing and filtering the bias voltage, and its capacitance can be between 1 nanofarad and 1 microfarad (for example: 0.1 microfarad). A first terminal of the capacitor C2 can be coupled to a ground terminal G2. A second end of the capacitor C2 can be coupled to a voltage source VCC. The voltage source VCC can be used to provide a voltage such as but not limited to 2.5V, 3.3V and so on.

Since the signals transmitted in the Ethernet network are generally designed to be transmitted through eight wires, the eight signals in the eight wires can be equally divided into four differential mode signal pairs, and the transmission sub-circuits 11, 12 , 13, and 14 may respectively correspond to one of the four differential mode signal pairs. The structures of the transmission sub-circuits 11, 12, 13, 14 are substantially the same, and their respective input and output types are also similar. Therefore, based on the principle of simplification of description, except for specific differences that will be described separately, only the transmission sub-circuit 11 is used as an example for description herein. Those with ordinary knowledge in the technical field of the present invention can understand the corresponding structures, functions and applicable parameters/set values of the transmission sub-circuits 12 , 13 , 14 according to the description of the transmission sub-circuit 11 . Therefore, the same details will not be repeated here.

The transmission sub-circuit 11 can process a group of Ethernet signals transmitted between the Ethernet physical layer device E11 and the Ethernet connection device E12. Since the structure of the transmission sub-circuit 12, 13, 14 is substantially the same as that of the transmission sub-circuit 11, those with ordinary knowledge in the technical field of the present invention can understand the transmission sub-circuit 12, 13, 14 according to the description of the transmission sub-circuit 11 How to process the other three groups of Ethernet signals between the Ethernet physical layer device E11 and the Ethernet connection device E12 through the same operation method as the transmission sub-circuit 11 . Therefore, the same details will not be repeated here.

The transmission sub-circuit 11 may include a transformer T11 to provide functions of DC isolation and signal coupling. The transformer T11 may include two windings CL11 and CL12. Both ends of the winding CL11 can be coupled to the Ethernet physical layer device E11, and both ends of the winding CL12 can be coupled to the Ethernet connection device E12. In some embodiments, the transformer T11 may be a 1:1 transformer. In addition, in some embodiments, the inductance of the transformer T11 may be between 60 microhenry (μH) and 1 millihenry (mH).

The winding CL11 may have a center tap coupled to the second terminal of the capacitor C2 and the voltage source VCC. In other words, the transformer T11 may have a single-side tap. Since the center tap is set on the Ethernet One end of the Ethernet physical layer device E11, so the voltage source VCC can provide a bias voltage for the PHY chip of the Ethernet physical layer device E11 through the secondary side winding CL11.

In addition to the transformer T11, the transmission sub-circuit 11 may further include two capacitors C11 and C12, both of which may be coupled to the Ethernet connection device E12. The capacitor C11 can be coupled between a first end of the winding CL12 and the capacitor C1. The capacitor C12 can be coupled between a second end of the winding CL12 and the capacitor C1. Capacitor C11, capacitor C12 and capacitor C1 can be used to provide a ground reference for the signal to avoid the problem of signal level shift caused by floating the output terminal of the transformer T11, and can provide differential mode impedance matching for the signal at the same time. In some embodiments, the capacitance of the capacitor C11 and the capacitor C12 may be between 0.5 picofarad (pF) and 20 picofarad respectively.

In some embodiments, an additional common-mode inductor can be added in each transmission sub-circuit to provide an additional common-mode filtering effect. The common mode inductor can be disposed on the primary side or the secondary side of the transformer T11. FIG. 2 shows an embodiment in which the common-mode inductor is disposed on the secondary side of the transformer T11 , and FIG. 3 shows an embodiment in which the common-mode inductor is disposed on the primary side of the transformer T11 .

More specifically, first refer to FIG. 2 . Similar to the transmission circuit 1, a transmission circuit 2 for Ethernet can also include four transmission sub-circuits 21, 22, 23, 24, capacitor C1 and capacitor C2, and the transmission sub-circuits 21, 22, 23, 24 The structure is also substantially the same, so those with ordinary knowledge in the technical field of the present invention can also understand the corresponding structures, functions and parameters applicable to each component in the transmission sub-circuit 22, 23, 24 according to the description for the transmission sub-circuit 21 /set value, and how the transmission sub-circuits 22, 23, 24 process the other three groups of Ethernet between the Ethernet physical layer device E11 and the Ethernet connection device E12 through the same operation mode as the transmission sub-circuit 21 network signal. Therefore, the same details will not be repeated here.

The transmission sub-circuit 21 is derived from the transmission sub-circuit 11. The difference between the two is that the transmission sub-circuit 21 includes a common mode inductor CM1 in addition to the transformer T11, the capacitor C11, and the capacitor C12 to provide the transmission sub-circuit 21 with additional common-mode filtering effect. The common mode inductor CM1 can be coupled between the Ethernet physical layer device E11 and the two ends of the winding CL11. More specifically, one end of the two windings on the common mode inductor CM1 can be coupled to the two ends of the winding CL11 , and the other end of the two windings can be coupled to the Ethernet physical layer device E11 . In other words, the two ends of the winding CL11 can be coupled to the Ethernet physical layer device E11 through the common mode inductor CM1 .

Next, refer to FIG. 3 . Similar to the transmission circuit 1, a transmission circuit 3 for Ethernet can also include four transmission sub-circuits 31, 32, 33, 34, capacitor C1 and capacitor C2, and the transmission sub-circuits 31, 32, 33, 34 The structure is also substantially the same, so those with ordinary knowledge in the technical field of the present invention can also understand the corresponding structures, functions and parameters applicable to each component in the transmission sub-circuit 32, 33, 34 according to the description of the transmission sub-circuit 31 /set value, and how the transmission sub-circuit 32, 33, 34 handles the other three groups of Ethernet between the Ethernet physical layer device E11 and the Ethernet connection device E12 through the same operation mode as the transmission sub-circuit 31 network signal. Therefore, the same details will not be repeated here.

The transmission sub-circuit 31 is derived from the transmission sub-circuit 11. The difference between the two is that the transmission sub-circuit 31 includes a common mode inductor CM1 in addition to the transformer T11, the capacitor C11, and the capacitor C12 to provide the transmission sub-circuit 31 with additional common-mode filtering effect. The common mode inductor CM1 can be coupled between the two ends of the winding CL12 and the Ethernet connection device E12. More specifically, one end of the two windings on the common mode inductor CM1 may be respectively coupled to the capacitor C11 and the capacitor C12, and jointly coupled to the Ethernet connection device E12, and the other ends of the two windings may be respectively Coupled to both ends of the winding CL12. That is, the two ends of the winding CL12 can be respectively coupled to the Ethernet network through the common mode inductor CM1. The device E12 is connected, so that the signal from the Ethernet connection device E12 is transmitted to the transformer T11 through the common mode inductor CM1.

FIG. 4 is a schematic diagram of another embodiment of the novel Ethernet transmission circuit. More specifically, as mentioned above, the Ethernet transmission circuit of the present invention is used to transmit Ethernet signals between the Ethernet physical layer device and the Ethernet connection device, and in FIG. 4 In an embodiment, the transmission circuit 4 is used to transmit Ethernet signals between an Ethernet physical layer device E21 and an Ethernet connection device E22, and the Ethernet physical layer device E21 is voltage-driven (that is, an Ethernet physical layer device including a voltage-driven PHY chip). The Ethernet connection device E22 is the same as the Ethernet connection device E12, and can be an Ethernet connector with an RJ-45 or 8P8C interface.

Refer to Figure 4. The transmission circuit 4 for the Ethernet can basically include four groups of transmission sub-circuits 41, 42, 43, 44 and the same capacitor C1 as that of the transmission circuits 1, 2, and 3, and can be coupled to the Ethernet Between the physical layer device E21 and the Ethernet connection device E22.

As mentioned earlier, since the signals transmitted in the Ethernet network are generally designed to be transmitted through eight wires, the eight signals in the eight wires can be equally divided into four differential mode signal pairs, and the transmission The sub-circuits 41 , 42 , 43 , 44 can respectively correspond to one of the four differential mode signal pairs. The structures of the transmission sub-circuits 41, 42, 43, 44 are substantially the same, and the respective input and output types are also similar. Therefore, based on the principle of simplification of description, except for specific differences that will be described separately, only the transmission sub-circuit 41 is used as an example for description herein. Those with ordinary knowledge in the technical field of the present invention can understand the corresponding structures, functions and applicable parameters/set values of the transmission sub-circuits 42 , 43 , 44 according to the description of the transmission sub-circuit 41 . Therefore, the same details will not be repeated here.

The transmission sub-circuit 41 can process a group of Ethernet signals transmitted between the Ethernet physical layer device E21 and the Ethernet connection device E22. Since the transmission sub-circuit 42, 43, 44 and the transmission sub-circuit The structure of the circuit 41 is substantially the same, so those with ordinary knowledge in the technical field of the present invention can understand how the transmission sub-circuits 42, 43, 44 operate in the same manner as the transmission sub-circuit 41 based on the description of the transmission sub-circuit 41. The other three groups of Ethernet signals between the Ethernet physical layer equipment E21 and the Ethernet connection equipment E22 are processed. Therefore, the same details will not be repeated here.

The transmission sub-circuit 41 may include a transformer T21 to provide functions of DC isolation and signal coupling. The transformer T21 may include two windings CL21 and CL22. Both ends of the winding CL21 can be coupled to the Ethernet physical layer device E21, and both ends of the winding CL22 can be coupled to the Ethernet connection device E22. In some embodiments, the transformer T11 may be a 1:1 transformer. In addition, in some embodiments, the inductance of the transformer T11 may be between 60 μH and 1 mH.

Since the PHY chip of the Ethernet physical layer device E21 is a voltage-driven type, it is not necessary to provide a bias for the PHY chip of the Ethernet physical layer device through a center tap as in the transmission circuits 1, 2, and 3. pressure. Therefore, the transformer T21 is different from the transformer T11 in that the winding CL21 may be a coil without a center tap.

In addition to the transformer T21 , the transmission sub-circuit 41 can also include the same two capacitors C11 and C12 as those in the transmission sub-circuits 11 , 21 , and 31 , which can be coupled to the Ethernet connection device E22 . The capacitor C11 can be coupled between a first end of the winding CL22 and the capacitor C1. The capacitor C12 can be coupled between a second end of the winding CL22 and the capacitor C1. Capacitor C11 , capacitor C12 and capacitor C1 can be used to provide a ground reference for the signal to avoid the problem of signal level shift caused by floating the output terminal of the transformer T21 , and can provide differential mode impedance matching for the signal at the same time. In some embodiments, the capacitance values of the capacitor C11 and the capacitor C12 may be between 0.5 picofarad and 20 picofarad respectively.

Although various embodiments are disclosed herein, the invention is not limited to these embodiments. Without departing from the spirit and scope of the present disclosure, equivalents or methods of the above-mentioned embodiments (for example, for Modifications and/or combinations of the above-mentioned embodiments also belong to a part of the present invention. The scope of protection of the present invention is subject to the content defined in the scope of the patent application.

1: Transmission circuit

11, 12, 13, 14: transmission sub-circuit

E11: Ethernet physical layer device

E12: Ethernet connection equipment

C1, C2, C11, C12: capacitance

CL11, CL12: winding

G1, G2: ground terminal

T11: Transformer

VCC: voltage source

Claims (13)

A transmission circuit for an Ethernet network, comprising: a first capacitor, a withstand voltage value of the first capacitor is not lower than 1000 volts; a second capacitor, one end of the second capacitor is coupled to ground, and the other end is coupled to a voltage source; and Four transmission sub-circuits, each of which is coupled between an Ethernet connection device and a current-driven Ethernet physical layer device, and each of which is used to transmit Ethernet A pair of differential mode signals of the network, and each of the transmission sub-circuits includes: A transformer includes a first winding and a second winding, both ends of the first winding are coupled to the Ethernet physical layer device, and both ends of the second winding are coupled to the Ethernet connection device, wherein the first winding includes a center tap, and the center tap is coupled to the voltage source and the second capacitor; and A third capacitor and a fourth capacitor are both coupled to the Ethernet connection device, and the third capacitor is coupled between the first end of the second winding and the first capacitor, and the fourth capacitor coupled between the second terminal of the second winding and the first capacitor. The transmission circuit as claimed in claim 1, wherein each of the transmission sub-circuits further includes a common mode inductor, coupled between the Ethernet physical layer device and the two ends of the first winding, and the first winding The two ends of both are coupled to the Ethernet physical layer device through the common mode inductor. The transmission circuit as claimed in claim 1, wherein each of the transmission sub-circuits further includes a common mode inductor coupled to the two ends of the second winding, the Ethernet connection device, the third capacitor and the fourth capacitor, and the two ends of the second winding are respectively coupled to the Ethernet connection device through the common mode inductor. The transmission circuit as claimed in claim 1, wherein a capacitance of the second capacitor is between 1 nanofarad and 1 microfarad. The transmission circuit as claimed in claim 1, wherein a capacitance value of the third capacitor and the fourth capacitor is both between 0.5 picofarads and 20 picofarads. The transmission circuit as claimed in claim 1, wherein a capacitance of the first capacitor is between 1 nanofarad and 0.1 microfarad. The transmission circuit as claimed in claim 1, wherein the transformer in each transmission sub-circuit is a 1:1 transformer. The transmission circuit as claimed in claim 1, wherein an inductance of the transformer in each of the transmission sub-circuits is between 60 microhenry and 1 millihenry. A transmission circuit for an Ethernet network, comprising: a first capacitor with a withstand voltage value not lower than 1000 volts; and Four transmission sub-circuits, each of which is coupled between an Ethernet connection device and a voltage-driven Ethernet physical layer device, and each of which is used to transmit Ethernet A pair of differential mode signals of the network, and each of the transmission sub-circuits includes: A transformer includes a first winding and a second winding, both ends of the first winding are coupled to the Ethernet physical layer device, and both ends of the second winding are coupled to the Ethernet connection equipment; and A second capacitor and a third capacitor are both coupled to the Ethernet connection device, and the second capacitor is coupled between a first end of the second winding and the first capacitor, the third The capacitor is coupled between a second end of the second winding and the first capacitor. The transmission circuit as claimed in claim 9, wherein the transformer in each transmission sub-circuit is a 1:1 transformer. The transmission circuit as claimed in claim 9, wherein an inductance value of the transformer in each transmission sub-circuit is between 60 microhenry and 1 millihenry. The transmission circuit as claimed in claim 9, wherein a capacitance value of the second capacitor and the third capacitor is between 0.5 picofarads and 20 picofarads. The transmission circuit as claimed in claim 9, wherein a capacitance of the first capacitor is between 1 nanofarad and 0.1 microfarad.

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