TWM625462U - Transmission circuit for ethernet - Google Patents

Abstract

A transmission circuit for Ethernet includes four sub-circuits. Each sub-circuit is coupled between a physical-layer device and a connection device of Ethernet, and is configured to transmit a pair of differential mode signals of the Ethernet network. Each sub-circuit includes a diode bridge, a first capacitor, and a second capacitor. In each sub-circuit, the first input terminal and the second input terminal of the diode bridge are both coupled to the connection device. The first capacitor is coupled between the first input terminal and the physical-layer device. The second capacitor is coupled between the second input terminal and the connection device. The transmission circuit also includes a third capacitor and a fourth capacitor. The third capacitor is coupled to the ground terminal and the positive output terminal of each diode bridge. The fourth capacitor is coupled to the ground terminal and the negative output terminal of each diode bridge.

Description

Transmission circuit for ethernet

The present invention relates to a transmission circuit used in an Ethernet network. 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.

Traditional network transformers for Ethernet (hereinafter referred to as "Ethernet transformers") include transformers with center taps, so they must be produced by manual winding, which results in their ability to adapt to changes in production capacity poor, and the production cost is relatively high. In addition, the traditional Ethernet transformer does not have the function of surge protection, which makes the Ethernet system vulnerable to surge interference (such as lightning strikes, static electricity or the switching action of the power supply of other loads in the same circuit). Environments often fail to function effectively, causing Ethernet service to have to be interrupted. In view of this, how to provide an Ethernet network transmission circuit that can be produced in an automated manner and has surge protection capability to replace the traditional Ethernet network transformer is a problem to be solved urgently in the technical field of the present invention. .

In order to solve at least the above-mentioned problems, the present invention discloses a transmission circuit for an Ethernet network. The transmission circuit contains four transmission subcircuits. Each of the transmission sub-circuits is coupled to an Ethernet network Between the body layer device and an Ethernet network connection device, and each of the transmission sub-circuits is used to transmit a pair of differential mode signals of the Ethernet network. Each of the transmission sub-circuits includes a diode bridge, a first capacitor and a second capacitor. In each transmission sub-circuit, a first input terminal and a second input terminal of the diode bridge are both coupled to the Ethernet connection device. The first capacitor is coupled between the first input end and the Ethernet physical layer device. The second capacitor is coupled between the second input terminal and the Ethernet connection device. The transmission circuit also includes a third capacitor and a fourth capacitor. The third capacitor is coupled to a ground terminal and a positive output terminal of each of the diode bridges. The fourth capacitor is coupled to the ground terminal and a negative output terminal of each of the diode bridges.

After referring to the accompanying drawings and the embodiments described later, those with ordinary knowledge in the technical field to which the present invention pertains can understand the main purpose, technical means and implementation aspects of the present invention.

As follows:

1, 2, 3, 4: Transmission circuit

11, 12, 13, 14, 21, 22, 23, 24: Transmission subcircuits

E1: Ethernet physical layer device

E2: Ethernet connection device

C1, C2, C11, C12: Capacitors

CL1, CL2: Coil

CM1: Common Mode Inductor

DB1: Diode Bridge

G1: ground terminal

IP1, IP2: input terminal

L1, L2: Diodes

ON1: negative output terminal

OP1: Positive output terminal

Below in conjunction with the drawings and specific embodiments, the present invention will be described in further detail, wherein: Fig. 1 is a schematic diagram of an implementation of the transmission circuit for the Ethernet network of the present invention; A schematic diagram of another implementation; FIG. 3 is a schematic diagram of another implementation of the transmission circuit of the present invention; and FIG. 4 is a schematic diagram of another implementation of the transmission circuit of the present invention.

The following examples are used to illustrate the technical content of the present invention, but not to limit the scope of the present invention. It should be noted that in the following embodiments and drawings, elements unrelated to the present invention have been omitted and not shown, and the dimensional relationship between the elements in the drawings is only for easy understanding, and is not used to limit the actual scale. In this article, terms such as "first", "second", "third", "fourth" and so on before some elements are only used to distinguish each element, rather than to limit the order among the various elements. relation.

FIG. 1 is a schematic diagram of an implementation of the novel Ethernet transmission circuit. Referring to FIG. 1 , a transmission circuit 1 for an Ethernet network may basically include four groups of transmission sub-circuits 11 , 12 , 13 and 14 . Since the eight signals of the Ethernet signal source can be equally divided into four differential-mode signal pairs, the transmission sub-circuits 11, 12, 13, and 14 can respectively correspond to the four differential-mode signal pairs of the Ethernet signal source. Mode signal to one of them. The transmission sub-circuits 11, 12, 13, and 14 have substantially the same structure, and their respective input and output types are also similar. Therefore, based on the principle of simplification of description, only the transmission sub-circuit 11 is used as an example for description, but those with ordinary knowledge in the technical field to which the present invention belongs can understand the transmission sub-circuits 12 and 13 according to the description of the transmission sub-circuit 11 , 14, the corresponding structure, function and applicable parameters/settings of each element.

The transmission sub-circuit 11 can process a set of Ethernet signals transmitted between an Ethernet PHY layer device E1 and an Ethernet connection device E2. The Ethernet connection device E2 may be an Ethernet connector with an RJ-45 or 8P8C interface. Since the structures of the transmission subcircuits 12 , 13 , 14 and the transmission subcircuit 11 are substantially the same, those skilled in the art to which the present invention pertains can understand the transmission subcircuits 12 , 13 , and 14 according to the description of the transmission subcircuit 11 How to process the other three sets of Ethernet signals between the Ethernet physical layer device E1 and the Ethernet connection device E2 through the same operation as the transmission sub-circuit 11 , the same details will not be repeated here. .

The transmission sub-circuit 11 may include a capacitor C11 and a capacitor C12. The capacitor C11 and the capacitor C12 can be coupled to the Ethernet physical layer device E1. The capacitor C11 and the capacitor C12 can be used to provide DC isolation and signal coupling for the transmission sub-circuit 11 . In some embodiments, the capacitance value of capacitor C11 and the capacitance value of capacitor C12 may each be between 50 nanofarads (nF) and 1 microfarad (uF). Depend on The structures of the transmission sub-circuits 11 , 12 , 13 and 14 can be substantially the same, so the corresponding capacitors in the transmission sub-circuits 12 , 13 and 14 can also have the same value range.

The transmission sub-circuit 11 may also include a diode bridge DB1. The capacitor C11 can be coupled to one input end IP1 of the diode bridge DB1, and the capacitor C12 can be coupled to the other input end IP2 of the diode bridge DB1. Both the input end IP1 and the input end IP2 of the diode bridge DB1 can be coupled to the Ethernet connection device E2. Since the diode bridge DB1 has parasitic capacitance, it can also meet the requirement of providing a specific impedance to ground at a specific frequency, and thus can replace the inductive components in the traditional network transformer. In addition, since the diode bridge DB1 is a semiconductor element, it has the advantage of not requiring repeated fine-tuning compared to inductive elements with higher tolerance in conventional network transformers.

The transmission circuit 1 may further include a capacitor C1 and a capacitor C2. The positive output terminal of the diode bridge DB1 (ie, the terminal that outputs a constant positive current) and the positive output terminals of the corresponding diode bridges in the transmission sub-circuits 12 , 13 , and 14 can both be coupled to the capacitor C1 . The negative output terminal of the diode bridge DB1 (ie, the terminal that outputs a constant negative current) and the negative output terminals of the corresponding diode bridges in the transmission sub-circuits 12 , 13 , and 14 can both be coupled to the capacitor C2 . Both the capacitor C1 and the capacitor C2 can be coupled to a ground terminal G1. The capacitor C1 and the capacitor C2 can provide the effect of isolating the transmission circuit 1 to the ground, so as to prevent the noise from the ground terminal from being transmitted back to the signal line.

In some embodiments, the ground terminal G1 may be in the form of chassis ground. In some embodiments, the capacitance values of capacitor C1 and capacitor C2 may each be between 1 nanofarad to 1 microfarad.

FIG. 2 is a schematic diagram of another embodiment of the transmission circuit of the present invention, which is derived from the transmission circuit 1 shown in FIG. 1 . 1 and 2 simultaneously, a transmission circuit for an Ethernet network 2 may also include transmission sub-circuits 11, 12, 13, and 14, and the component composition of each transmission sub-circuit and the connection relationship between each transmission sub-circuit and the Ethernet physical layer device E1 and the Ethernet connection device E2 Both can be the same as the transmission circuit 1, and the difference between the two is that the transmission circuit 2 may further include a diode L1 and a diode L2.

The diode L1 can be connected in parallel with the capacitor C1, and the anode of the diode L1 can be coupled to the positive output terminal OP1 of the diode bridge DB1 and the corresponding diode bridges in the transmission sub-circuits 12, 13 and 14. Positive output. The cathode of the diode L1 can be coupled to the ground terminal G1. Similarly, the diode L2 can be connected in parallel with the capacitor C2, and the cathode of the diode L2 can be coupled to the negative output terminal ON1 of the diode bridge DB1 and the corresponding diodes in the transmission sub-circuits 12, 13 and 14. The negative output terminal of the bridge, and the anode of the diode L2 can be coupled to the ground terminal G1. In certain embodiments, the capacitance values of diode L1 and diode L2 may each be between 1 picofarad and 1000 picofarads. In some embodiments, diode L1 and diode L2 may be two diodes that belong to the same package.

The combination of the diode bridge and the capacitors C1 and C2 and the diodes L1 and L2 in each transmission sub-circuit can provide the transmission circuit 2 with the functions of common mode filtering protection and impedance matching. Specifically, a suitable differential mode impedance can be obtained by adjusting the capacitance values of the diodes L1 and L2 and the capacitors C1 and C2 , and the signal crosstalk generated by other transmission channels to the transmission circuit 2 can be reduced.

FIG. 3 is a schematic diagram of another implementation of the transmission circuit of the present invention, which is derived from the transmission circuit 1 shown in FIG. 1 . 1 and 3 simultaneously, a transmission circuit 3 for Ethernet may include four transmission sub-circuits 21, 22, 23, 24 and capacitors C1, C2, and similar to the case in the transmission circuit 1, the transmission The structures of the sub-circuits 21, 22, 23, and 24 are substantially the same, and their respective input and output types are also similar. Therefore, this article only describes the structure of the transmission sub-circuit 21 in detail, which belongs to the technical field of the present invention. Those with ordinary knowledge in the present invention can clearly know the corresponding structures and connection configurations of the transmission sub-circuits 22 , 23 and 24 according to the description of the transmission sub-circuit 21 .

Like the transmission subcircuit 11 , the transmission subcircuit 21 may also include a capacitor C11 , a capacitor C12 , a diode bridge DB1 , a capacitor C1 , and a capacitor C2 . The difference between the transmission sub-circuit 21 and the transmission sub-circuit 11 is that it may further include a common mode inductor CM1. The common mode inductor CM1 may include a coil CL1 and a coil CL2, the coil CL1 may be coupled between the capacitor C11 and the input terminal IP1 of the diode bridge DB1, and the coil CL2 may be coupled between the capacitor C12 and the diode bridge Between the input terminals of DB1 and IP2. In other words, in the transmission sub-circuit 21, the capacitor C11 may be coupled to the input terminal IP1 via the coil CL1, and the capacitor C12 may be coupled to the input terminal IP2 via the coil CL2. The common mode inductor CM1 may further include a magnetic core, and the coil CL1 and the coil CL2 are wound around the magnetic core to form a common mode inductor.

The common-mode inductors in each transmission sub-circuit (eg, the common-mode inductor CM1 in the transmission sub-circuit 21 ) can provide additional common-mode filtering protection for the transmission circuit 3 . In some embodiments, the inductance values of the common mode inductors in each transmission sub-circuit may each be between 10 nanohenry (nH) and 5 microhenry (uH).

FIG. 4 is a schematic diagram of another implementation of the transmission circuit of the present invention, which is jointly derived from the transmission circuit 2 and the transmission circuit 3 shown in FIGS. 2 and 3 . Referring to FIGS. 2 , 3 , and 4 at the same time, a transmission circuit 4 used for the Ethernet network may not only include capacitors C1 and C2 shared by the transmission circuit 2 and the transmission circuit 3 , but also include the capacitors C1 and C2 in the transmission circuit 2 . The diodes L1, L2 and the transmission sub-circuits 21, 22, 23, 24 in the transmission circuit 3, that is, the transmission circuit 4 combines the characteristics of the transmission circuit 2 and the transmission circuit 3. With this design, compared to the transmission circuit 2 and the transmission circuit 3, the transmission circuit 4 has both advantages to provide further common-mode filtering protection and impedance matching effects. Since the present invention belongs to the technical field Those with ordinary knowledge in the present invention can understand the specific structures of the transmission sub-circuits 21 , 22 , 23 , and 24 in the transmission circuit 4 according to the description about the transmission circuit 3 , so the detailed description is omitted.

Similar to the transmission circuit 2 and the transmission circuit 3, in the transmission circuit 4, the diode L1 can be connected in parallel with the capacitor C1, and the anode of the diode L1 can be coupled to the anode of the diode bridge DB1 of the transmission sub-circuit 21 The output terminal OP1 and the positive output terminals of the corresponding diode bridges in the transmission sub-circuits 22 , 23 and 24 . The cathode of the diode L1 can be coupled to the ground terminal G1. Similarly, the diode L2 can be connected in parallel with the capacitor C2, and the cathode of the diode L2 can be coupled to the negative output terminal ON1 of the diode bridge DB1 of the transmission sub-circuit 21 and the transmission sub-circuits 22, 23 and 24. The negative output terminal of the corresponding diode bridge, and the anode of the diode L2 can be coupled to the ground terminal G1. In certain embodiments, the capacitance values of diode L1 and diode L2 may each be between 1 picofarad and 1000 picofarads. In some embodiments, diode L1 and diode L2 may be two diodes that belong to the same package.

To sum up, the transmission circuits 1, 2, 3, and 4 for the Ethernet network in this new model do not need to be produced by manual winding, etc., have a structure that can be automated production, and can provide the Ethernet network Signal coupling, DC isolation, surge protection and other functions required for transmission. Therefore, the new Ethernet network transmission circuit has the ability to replace the traditional Ethernet network transformer, and provides higher environmental adaptability for the transmission of the Ethernet network.

The above-mentioned examples are only used to illustrate the embodiments of the present invention and to illustrate the technical characteristics of the present invention, and are not intended to limit the protection scope of the present invention. Any changes or equivalent arrangements that can be easily accomplished by those with ordinary knowledge in the technical field to which the present invention pertains fall within the claimed scope of the present invention.

1: Transmission circuit

11, 12, 13, 14: Transmission subcircuits

E1: Ethernet physical layer device

E2: Ethernet connection device

C1, C2, C11, C12: Capacitors

DB1: Diode Bridge

G1: ground terminal

IP1, IP2: input terminal

ON1: negative output terminal

OP1: Positive output terminal

Claims (8)

A transmission circuit for an Ethernet network, comprising: Four transmission sub-circuits, each of which is coupled between an Ethernet physical layer device and an Ethernet connection device, and each of the transmission sub-circuits is used to transmit a pair of Ethernet differential mode signal, and each of the transmission sub-circuits includes: a diode bridge, a first input end and a second input end of the diode bridge are both coupled to the Ethernet connection device; a first capacitor coupled between the first input terminal and the Ethernet physical layer device; and a second capacitor coupled between the second input terminal and the Ethernet connection device; a third capacitor coupled to a ground terminal and a positive output terminal of each of the diode bridges; and A fourth capacitor is coupled to the ground terminal and a negative output terminal of each of the diode bridges. The transmission circuit of claim 1, further comprising: A first diode is connected in parallel with the third capacitor, an anode of the first diode is coupled to the positive output terminal of each of the diode bridges, and a cathode of the first diode is coupled to connected to the ground terminal; and A second diode is connected in parallel with the fourth capacitor, and a cathode of the second diode is coupled to the negative output terminal of each of the diode bridges, and an anode of the second diode is coupled to connected to the ground terminal. The transmission circuit of claim 2, wherein the capacitance value of the first diode and the capacitance value of the second diode are each between 1 picofarad and 1000 picofarads. The transmission circuit of claim 2, wherein the first diode and the second diode are two diodes that belong to the same package. The transmission circuit of claim 1, wherein the capacitance values of the first capacitor and the second capacitor in each of the transmission sub-circuits are respectively between 50 nanofarads and 1 microfarad. The transmission circuit of claim 1, wherein the capacitance values of the third capacitor and the fourth capacitor are each between 1 nanofarad and 1 microfarad. The transmission circuit of claim 1 or 2, wherein each of the transmission sub-circuits further includes a common mode inductor, the common mode inductor includes a first coil and a second coil, the first coil is coupled to the first coil Between a capacitor and the first input terminal, the second coil is coupled between the second capacitor and the second input terminal. The transmission circuit of claim 7, wherein the inductance values of the common mode inductors in each of the transmission sub-circuits are respectively between 10 nanohenry and 5 microhenry.

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