CN110971212A

CN110971212A - Pulse filter

Info

Publication number: CN110971212A
Application number: CN201811136257.4A
Authority: CN
Inventors: 范云光
Original assignee: Individual
Current assignee: Individual
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-07

Abstract

The invention discloses a pulse filter, which comprises four first magnetic rings, four first annular coils, four second magnetic rings, four second annular coils, four second middle tap connecting wires, four third magnetic rings, four third annular coils, four third middle tap connecting wires, glue for accommodating the components and providing isolation protection, and a shell for connecting an RJ45 connector to a network integrated circuit and providing a pulse filtering function. Particularly, the first, second and third magnetic coils are used together with the wound first, second and third toroidal coils as a transformer, an input impedance and an output impedance, respectively, and the input impedance and the output impedance are designed to be impedance matched, so that the transmission loss and the waveform distortion between the network connector and the network integrated circuit can be greatly reduced, and the transmission distance can be effectively increased.

Description

Pulse filter

Technical Field

The invention relates to a pulse filter, in particular to a pulse filter which uses a first magnetic ring, a second magnetic ring and a third magnetic ring together with a first annular coil, a second annular coil and a third annular coil which are wound and respectively used as a transformer, input impedance and output impedance, and is specially designed to make the input impedance and the output impedance be impedance matching, thereby greatly reducing the transmission loss and waveform distortion between a network connector and a network integrated circuit, effectively improving the transmission distance and being very suitable for an RJ45 connector of a 10G-BASE-T Ethernet communication network or a 10G BASE-T network interface which operates at the transmission speed of 10 Gbps.

Background

Ethernet is a very popular network, and as is well known, PoE powering is a technology that can transmit power and data to devices over twisted pair lines in ethernet, and 8P8C connector, also commonly known as RJ45, is a common twisted pair wiring plug in ethernet, where 8P of 8P8C (8 Position 8 Contact) refers to 8 positions (8 grooves) and 8C refers to 8 contacts (8 metal contacts).

For example, in the case of 100Base-T4, the RJ45 connector includes four differential signal pairs, which are TD1+ pin (data + transfer), TD 1-pin (data-transfer), TD2+ pin, TD 2-pin, TD3+ pin, TD 3-pin, TD4+ pin, and TD 4-pin.

Furthermore, gigabit Ethernet (Fast Ethernet, 10/100M Ethernet) uses only four lines and uses differential signaling to reduce emi, where two TX lines are twisted together and two RX receive lines are twisted together. Therefore, the parallel lines are the connection method with two ends being EIA-568-A or EIA-568-B, and the jumper lines are the connection method with one end using EIA-568-A and the other end using EIA-568-B.

In addition, in Gigabit Ethernet (1000M Ethernet) or Power over Ethernet (PoE), all four pairs of differential pairs are used.

For example, as shown in fig. 1 and 2, the RJ45 connector SK of the prior art generally uses two magnetic rings accommodated in a housing 10 having a plurality of pins 11 as a network filter, i.e., a first main magnetic ring 20 and a second magnetic ring 30, respectively, for connecting to a network IC, thereby providing an isolated differential signal transmission function. Furthermore, the first magnetic ring 20 is mainly used as a transformer, has a differential signal ratio of 1:1, is used for differential signal transmission, has the functions of impedance matching, waveform restoration, signal clutter suppression, voltage isolation and the like, can increase the transmission distance, and can keep the connected network integrated circuit IC isolated from the outside, thereby further enhancing the anti-interference capability. In addition, the second magnetic ring 30 is used as the input impedance Rin, and obviously, the prior art only has the input impedance Rin, but does not have the output impedance, so the input impedance and the output impedance on the whole transmission interface are not matched, which causes the transmission current I to become larger, increases the transmission power, seriously affects the actual transmission distance, and greatly limits the application field.

In addition, although the input impedance Rin provided by the second magnetic ring 30 can effectively filter the common mode noise of the RJ45 connector SK, the high frequency noise generated in the network IC will lack high impedance to filter the common mode noise, which causes waveform distortion and seriously affects the transmission quality of the signal.

A general prior art implementation can be seen in fig. 3, which is a well-known technique and will not be described in further detail.

Therefore, there is a need for an innovative pulse filter, which includes three toroidal coils as an input impedance, a transformer, and an output impedance, respectively, all built in an insulating housing, and is designed to match the input impedance and the output impedance, so as to reduce the transmission loss of the whole circuit to a very low level and effectively increase the transmission distance, thereby solving all the problems of the prior art.

Disclosure of Invention

The present invention provides a pulse filter, which includes four first magnetic rings, four first toroidal coils, four second magnetic rings, four second toroidal coils, four second center tap connection lines, four third magnetic rings, four third toroidal coils, four third center tap connection lines, and a glue and a housing for accommodating the above components and providing isolation protection, and can connect the RJ45 connector SK to the network integrated circuit IC and has a pulse filtering function.

Specifically, each first toroidal coil is wound around the corresponding first magnetic ring to form a transformer, each second toroidal coil is wound around the corresponding second magnetic ring to form an input impedance, and each third toroidal coil is wound around the corresponding third magnetic ring to form an output impedance.

The shell is provided with a plurality of pins which are connected to the second annular coil and the third annular coil. Furthermore, each second middle tap connecting line is connected to the corresponding pin through the middle tap of one side of the first annular coil, and each third middle tap connecting line is connected to the corresponding pin through the middle tap of the other side of the first annular coil.

In particular, the corresponding second toroidal coil, first toroidal coil and third toroidal coil are connected in sequence, and the network connector is connected to the network integrated circuit through the pins.

In the invention, the first, second and third magnetic coils are used as transformer, input impedance and output impedance, and the input impedance and output impedance are designed to be impedance matching, so the transmission loss and waveform distortion between the network connector and the network IC can be greatly reduced, and the transmission distance can be effectively increased.

Drawings

FIG. 1 is a diagram of a prior art network filter.

FIG. 2 is a schematic diagram of a simple equivalent circuit of a prior art network filter.

Fig. 3 shows a detailed equivalent circuit of a prior art network filter.

FIG. 4 is a diagram of a pulse filter according to a first embodiment of the present invention.

FIG. 5 is a circuit diagram of a pulse filter according to a first embodiment of the present invention.

FIG. 6 is a simplified equivalent circuit diagram of a pulse filter according to a first embodiment of the present invention.

Fig. 7 shows a detailed equivalent circuit of the pulse filter according to the first embodiment of the present invention.

FIG. 8 is a diagram of a pulse filter according to a second embodiment of the present invention.

FIG. 9 is a circuit diagram of a pulse filter according to a second embodiment of the present invention.

Detailed Description

The embodiments of the present invention will be described in more detail with reference to the drawings and the accompanying reference numerals, so that those skilled in the art can implement the embodiments of the present invention after studying the specification.

Referring to fig. 4 and fig. 5, a schematic diagram and a circuit diagram of a pulse filter according to a first embodiment of the invention are shown, respectively. As shown in fig. 4 and 5, the pulse filter according to the first embodiment of the present invention includes a housing 10, four first magnetic rings 20, four first toroidal coils 22, four second magnetic rings 30, four second toroidal coils 32, four second center-tap connection lines 34, four third magnetic rings 40, four third toroidal coils 42, and four third center-tap connection lines 44 for connecting the RJ45 connector SK to the network integrated circuit IC to have a pulse filtering function, wherein all of the first magnetic rings 20, the first toroidal coils 22, the second magnetic rings 30, the second toroidal coils 32, the second center-tap connection lines 34, the third magnetic rings 40, the third toroidal coils 42, and the third center-tap connection lines 44 are accommodated in the housing 10.

Preferably, the first magnetic ring 20, the second magnetic ring 30, and the third magnetic ring 40 are iron core magnetic rings, and the first toroidal coil 22, the second toroidal coil 32, the second center-tap connection line 34, the third toroidal coil 42, and the third center-tap connection line 44 are two twisted enameled wires.

Each first ring coil 22 is wound around the corresponding first magnetic ring 20, each second ring coil 32 is wound around the corresponding second magnetic ring 30, and each third ring coil 42 is wound around the corresponding third magnetic ring 40, thereby forming four groups of pulse filtering units. In addition, the housing 10 has a plurality of pins 11 for connecting the first loop coil 32, the second center-tap connection line 34, the third loop coil 42 and the third center-tap connection line 44.

In summary, the pulse filter according to the first embodiment of the present invention is disposed between the RJ45 connector SK and the network IC, and is connected to the RJ45 connector SK and the network IC through the pin 11, so as to provide a pulse filtering function, reduce the transmission loss of the whole circuit, and effectively increase the transmission distance.

Specifically, each first ring coil 22 is wound around the corresponding first magnetic ring 20 to form a transformer, each second ring coil 32 is wound around the corresponding second magnetic ring 30 to form an input impedance, and each third ring coil 42 is wound around the corresponding third magnetic ring 40 to form an output impedance, so that the present invention can bi-directionally transmit the electrical signal from the RJ45 connector SK to the network integrated circuit IC through the input impedance, the transformer, and the output impedance in sequence through the pins 11.

Further, the RJ45 connector SK mentioned in the present invention includes four sets of difference signal pair pins (i.e. TD1+ pin, TD 1-pin, TD2+ pin, TD 2-pin, TD3+ pin, TD 3-pin, TD4+ pin, TD 4-pin), and further includes TCT1 pin, TCT2 pin, TCT3 pin, and TCT4 pin, which are respectively disposed at each set of difference signal pair pins, as shown in the left side of fig. 4. Furthermore, marked on the right side of fig. 4 are MCT1 pin, MX 1-pin, MX 1-pin, MCT2 pin, MX 2-pin, MX 2-pin, MCT3 pin, MX 3-pin, MX 3-pin, MCT4 pin, MX 4-pin, MX 4-pin, TCT1 pin, TD1+ pin, TD 1-pin, TCT2 pin, TD2+ pin, TD 2-pin, TCT3 pin, TD3+ pin, TD 3-pin, TCT4 pin, TD4+ pin, TD 4-pin of the network integrated circuit IC.

More specifically, the second toroid 32 is further connected between the RJ45 connector SK and the first toroid 22, and the third toroid 42 is further connected between the first toroid 22 and the network IC. Further, the second toroidal coil 32 is connected to one side (left side in the drawing) of the first toroidal coil 22, and the third toroidal coil 42 is connected to the other side (right side in the drawing) of the first toroidal coil 22, and in particular, the TCT1 pin, the TCT2 pin, the TCT3 pin, and the TCT4 pin are middle taps connected to the left side of the first toroidal coil 22, i.e., the second middle tap connection line 34, and pass around the second magnetic loop 30, and the MCT1 pin, the MCT2 pin, the MCT3 pin, and the MCT4 pin are middle taps connected to the right side of the first toroidal coil 22, i.e., the third middle tap connection line 44, and pass around the third magnetic loop 40.

In essence, the second toroid 32 and the third toroid 42 are regarded as the input impedance Rin and the input impedance Rout, respectively, in terms of circuit characteristics, as shown in the simple equivalent circuit of fig. 6. Since the input impedance Rin and the input impedance Rout of the second toroidal coil 32 and the third toroidal coil 42 are specially designed to match each other, for example, 50 Ω, the conduction current I flowing through the pulse filter of the present invention can be greatly reduced and approach to zero current, thereby achieving the purpose of reducing power consumption and further increasing the effective transmission distance.

Since the second middle tap connection line 34 is connected to the middle tap of the left side of the first toroidal coil 22 from the pin TCT1, the pin TCT2, the pin TCT3 and the pin TCT4 and passes through the second magnetic ring 30, and the third middle tap connection line 44 is connected to the middle tap of the right side of the first toroidal coil 22 from the pin MCT1, the pin MCT2, the pin MCT3 and the pin MCT4 and passes through the third magnetic ring 40, the second magnetic ring 30 and the third magnetic ring 40 have the function of a choke coil, which can effectively filter high-frequency noise and further improve the signal transmission quality.

To further understand the features of the present invention, referring to fig. 7, the detailed equivalent circuit of the pulse filter of the first embodiment of the present invention is compared with fig. 3, and it is obvious that the present invention has both input impedance and output impedance, but only input impedance in the prior art.

Referring to fig. 7 and 8, a schematic diagram and a circuit diagram of a pulse filter according to a second embodiment of the present invention are shown. It is to be noted that the pulse filter of the second embodiment of the present invention is similar to the first embodiment of the present invention and has the same elements, including the housing 10 and four sets of the first magnetic ring 20, the first toroidal coil 22, the second magnetic ring 30, the second toroidal coil 32, the third magnetic ring 40 and the third toroidal coil 43, while the technical difference therebetween is that the second intermediate tap connection line 34 connected to the TCT1 pin, the TCT2 pin, the TCT3 pin and the TCT4 pin by the intermediate tap of the left side of the first toroidal coil 22 in the second embodiment is designed to pass around without passing through the second magnetic ring 30, and similarly, the third intermediate tap connection line 44 connected to the MCT1 pin, the MCT2 pin, the MCT3 pin and the MCT4 pin by the intermediate tap of the right side of the first toroidal coil 22 is designed to pass around without passing through the third magnetic ring 40. Therefore, the pulse filter of the second embodiment does not provide the effect of a choke coil to the transmission signal.

In summary, the present invention is characterized in that three toroidal coils are used as input impedance, transformer, output impedance, and are embedded in the insulating housing for isolation protection, not only the input impedance can effectively filter the common mode noise from the RJ45 connector, but also the output impedance can filter the high frequency noise generated from the network IC to prevent the waveform distortion, and the input impedance and the output impedance are specially designed to be impedance matching, so the transmission loss of the whole circuit is reduced to a very low level, and the functions of signal transmission, waveform repair, signal noise suppression, voltage isolation, etc. can be effectively achieved, thereby increasing the transmission distance, isolating the chip from the outside, and enhancing the anti-interference capability.

The foregoing is illustrative of the preferred embodiment of the present invention and is not to be construed as limiting thereof, since any modification or variation thereof within the spirit of the invention is intended to be covered thereby.

Wherein the reference numerals are as follows:

10 casing

11 pin

20 first magnetic ring

22 first toroidal coil

30 second magnetic ring

32 second toroidal coil

34 second center tap connection line

40 third magnetic ring

42 third toroidal coil

44 third center tap connection line

I conducting current

IC network integrated circuit

Rin input impedance

Rout output impedance

SK network connector

Claims

1. A pulse filter for connecting a network connector to a network integrated circuit to provide a pulse filtering action, comprising:

a fourth first magnetic ring;

the first annular coils are wound on the corresponding first magnetic rings to form a transformer;

a fourth magnetic ring;

the second toroidal coils are wound on the corresponding second magnetic ring to form an input impedance;

a fourth magnetic ring;

the fourth annular coil is wound on the corresponding fourth magnetic ring to form an output impedance;

a fourth second center tap connection line;

a fourth center tap connection line; and

a housing for accommodating the first magnetic ring, the first toroidal coil, the second magnetic ring, the second toroidal coil, the third magnetic ring, and the third toroidal coil, and having a plurality of pins connected to the second toroidal coil and the third toroidal coil,

each second middle tap connecting line is connected to the corresponding pin through a middle tap on one side of the first ring coil, each third middle tap connecting line is connected to the corresponding pin through a middle tap on the other side of the first ring coil, and the corresponding second ring coil, the first ring coil and the third ring coil are sequentially connected, and the network connector is connected to the network integrated circuit through the pins.

2. The pulse filter of claim 1 wherein the network connector is an RJ45 connector and includes a TCT1 pin, a TD1+ pin, a TD 1-pin, a TCT2 pin, a TD2+ pin, a TD 2-pin, a TCT2 pin, a TD2+ pin, and a TD 2-pin, and the network ic includes a MCT2 pin, an MX 2-pin, an MCT 2-pin, an MX 2-pin, and a connector 2-pin corresponding to the TCT2 pin, the TD 8672-pin, the TD2+ pin, the TD 2-pin, the TCT 2-pin, the MCT 2-2 pin, the MCT 2-2 pin, the TCT3 pin, the TD3+ pin, the TD 3-pin, the TCT4 pin, the TD4+ pin, and the TD 4-pin.

3. The pulse filter of claim 2 wherein the second intermediate-tap connection is connected to one of the TCT1 pin, the TCT2 pin, the TCT3 pin, and the TCT4 pin of the network connector via the pin, and the third intermediate-tap connection is connected to one of the MCT1 pin, the MCT2 pin, the MCT3 pin, and the MCT4 pin of the network integrated circuit via the pin.

4. The pulse filter of claim 1, wherein said second center-tap connection line is connected to said corresponding pin by said first toroid being threaded around a second toroid, and said third center-tap connection line is connected to said corresponding pin by said third toroid being threaded around a third toroid.

5. The pulse filter of claim 1, wherein said second center tap connection line is not routed around a second magnetic loop but is directly connected to said corresponding pin by said first toroidal coil, and said third center tap connection line is not routed around a third magnetic loop but is directly connected to said corresponding pin by said third toroidal coil.

6. The pulse filter of claim 1, wherein the first magnetic ring, the second magnetic ring, and the third magnetic ring are iron core magnetic rings.

7. The pulse filter of claim 1 wherein the first toroid, the second center tap connection line, the third toroid, and the third center tap connection line are two twisted wires.