TWM508853U - Noise cancellation circuit for network signals - Google Patents

Description

Network signal filtering noise circuit

The present invention provides a filtering noise circuit for a network signal, in particular, a circuit design in which a processing circuit can be grounded through a series connection of a resistor on a circuit board and a first capacitor and a second capacitor through an autotransformer. Some circuit boards achieve the purpose of reducing production costs and have more practical and applicable effects.

According to the rapid development of computer technology, the development trend of its computer is also moving towards the direction of computing power, speed and small size. Because network communication technology is also rapidly developing and bringing people to life, study, work and leisure. Entering a new realm that is different from the past, enabling people to transmit the same instant information, advertisements or correspondences through the Internet, while searching for various information, instant messaging or online through the Internet. Games make the relationship between people and the Internet more eager and inseparable.

In addition, the part of the network is to use two methods of cable connection and wireless transmission to transmit data. The cable connection technology needs to be equipped with a network connector, and as the network is used more and more, the network The data capacity of the transmission is also increasing. From the early 10Mbps, 100Mbps and 1Gbps, even the current fiber-optic network transmission speed can reach more than 10Gbps. However, when the network signal line is affected by lightning strikes, the network signal is affected. When the network connector of the line connection receives a high voltage or a sudden wave of lightning strike, it will be caused by an instantaneous high voltage or The surge causes damage to various electronic components, network chips, etc. on the processing circuit, so that the network signal transmission is unstable, interrupted or unable to be connected, or even the circuit board or electronic device to which the network chip is connected (such as Computer mainframes or hubs, etc., may be damaged or damaged by the impact of transient high voltage or sudden waves; in addition, the types of general networks can be roughly divided into regional networks, metro networks, and wide area networks according to the geographical scope covered. , wireless network, Internet channel, etc., and in the process of network signal transmission, it is easy to be affected by the interference of electromagnetic waves or noise of peripheral electronic components, resulting in instability of network signal transmission, and the general practice is in the network. A filter component is internally provided in the connector to filter the network signal to reduce interference from electromagnetic waves and noise.

In the current network signal processing circuit, in order to prevent instantaneous high voltage or surge damage to the network chip and the circuit board, there are manufacturers to set a plurality of transformers in the network connector, as shown in the fourth figure, wherein the lightning protection The transformer A1 of the module A has a primary side coil A11 and a secondary side coil A12, and a resistor A2 and a first capacitor A3 are respectively connected in series at the center tap A121 of the secondary side coil A12, and then connected to the ground terminal A31. The second tap A4 is connected in series with the second tap A4 of the primary side coil A11 and then connected to the ground terminal A41. When a high voltage or a surge occurs during the transmission of the network signal, the coupling function of the transformer A1 can be performed. The instantaneous high voltage, surge, etc. are stepped down, and are transmitted to the ground terminal A31 through the resistor A2 and the first capacitor A3 to be removed, so that the high voltage or the surge is not transmitted to the network wafer to avoid damage. However, the complex transformer A1 circuit layout needs to be performed in the processing circuit inside the network connector, and the circuit board area applied by the processing circuit is relatively large, and the overall working time and cost are difficult to be effectively reduced. The network connector considers the specifications of the technology of Power over Ethernet (PoE power supply, which transmits power and data through twisted pair), and is in transformer A1. The function of eliminating the interference signal is achieved by connecting the resistor A2 and the first capacitor A3 in series, but the circuit design of the transformer A1 connecting the resistor A2 and the first capacitor A3 is not necessary, and even if the resistor A2 and the first capacitor A3 are not provided, it will not be affected. The application function of the transformer A1, so the existing circuit board that meets the PoE power supply specification has the resistor A2 and the first capacitor A3, which is a waste of the transformer A1, but can not substantially improve or improve the function of the transformer A1 application. .

In addition, in order to solve the problem of noise interference during signal transmission in the above-mentioned network signal processing circuit, the applicant has used the existing electronic components and circuit design to carry out research and development improvement, and is equipped with signal processing on the circuit board. For the circuit, please refer to the fifth figure, wherein a plurality of circuit channels B3 are connected between the first connection end B1 and the second connection end B2 of the processing circuit B, and coupling capacitors are respectively connected to each circuit channel B3. B4 and the autotransformer B5 are connected to the ground terminal B51, and a common mode inductor unit C is connected in parallel between any two adjacent circuit channels B3, when the network signal is transmitted to the circuit channel B3 via the first connection terminal B1. The low-pass filtering (Low Pass) or the electromagnetic wave interference generated by the common mode current can be eliminated through each common mode inductor unit C, and the electrical and coupling signals are isolated via the coupling capacitors B4, and the autotransformer B5 filter net After the noise in the signal, it is transmitted to the ground terminal B51 for removal, so that the electromagnetic wave or noise interference contained in the network signal can be filtered out to achieve stable transmission network communication. For the purpose, the current circuit board that meets the PoE power supply specification is provided with a resistor A2 and a first capacitor A3. The circuit design of the processing circuit B cannot be applied to the existing circuit board, but must be processed. Circuit B produces a suitable circuit board, or it needs to match the electronic components on the circuit board to change the circuit layout, and increase the complexity of the circuit layout, and use more electronic components to occupy more power. The road area and the labor and cost required for the overall production are relatively improved, which is the direction for those who are engaged in this industry to research and improve.

Therefore, in view of the above-mentioned problems and shortcomings, the new creators have collected the relevant information through various assessments and considerations, and have used the trial and modification of many years of R&D experience in this industry to design such network signals. A new type of noise filtering circuit was born.

The main purpose of the present invention is that a circuit channel is connected between the first connection end and the second connection end of the processing circuit, and a common mode inductance unit is connected in parallel between any two adjacent circuit channels, and each circuit channel The coupling capacitor is connected in series on the side adjacent to the common mode inductor unit, and an autotransformer is connected in parallel between any adjacent circuit channels, so that the electromagnetic wave or noise in the network signal transmitted by the circuit channel can be included. For filtering, the processing circuit can be applied to the circuit design of the grounding circuit of the first capacitor and the second capacitor respectively connected to the first wiring and the second wiring by the autotransformer. The existing circuit board that meets the PoE power supply specification does not need to change the circuit layout with the electronic components set on the circuit board, and achieves the purpose of reducing the production cost, and has more practicality and applicability.

The second purpose of the present invention is that the first connection end and the second connection end of the processing circuit are electrically connected to the network connector and the network chip respectively, and the electromagnetic wave is received during the transmission of the network signal by the network connector. Or noise interference, the noise in each circuit channel can be filtered through the common mode inductor unit, and then through the coupling capacitor and the autotransformer, and then through the resistor, the first capacitor and the second capacitor on the circuit board. Transmission to the ground for troubleshooting, so that the network signal can be stably transmitted to the network chip for processing, to avoid instability or interruption in the signal transmission process, and to ensure the quality of the network signal transmission is more stable .

1‧‧‧Processing circuit

10‧‧‧ boards

10a‧‧‧ Grounding

10b‧‧‧ Grounding

101‧‧‧resistance

102‧‧‧first capacitor

103‧‧‧second capacitor

11‧‧‧First connection

12‧‧‧second connection

13‧‧‧Circuit channel

14‧‧‧Coupling capacitor

15‧‧‧Autotransformer

151‧‧‧First wiring

152‧‧‧second wiring

2‧‧‧Common mode inductance unit

3‧‧‧Network Chip

4‧‧‧Network connector

A‧‧‧Lightning protection module

A1‧‧‧Transformer

A11‧‧‧ primary side coil

A111‧‧‧Intermediate tap

A12‧‧‧second side coil

A121‧‧‧Intermediate tap

A2‧‧‧resistance

A3‧‧‧first capacitor

A31‧‧‧ Grounding terminal

A4‧‧‧second capacitor

A41‧‧‧ Grounding terminal

B‧‧‧Processing Circuit

B1‧‧‧ first connection

B2‧‧‧second connection

B3‧‧‧ Circuit Channel

B4‧‧‧Coupling Capacitor

B5‧‧‧Autotransformer

B51‧‧‧ Grounding terminal

C‧‧‧Common mode inductance unit

The first picture is a simple circuit diagram of the creation.

The second picture is a block diagram of the creation.

The third figure is a block diagram of a preferred embodiment of the present invention.

The fourth figure is a simplified circuit diagram of a conventional lightning protection module.

The fifth diagram is a simplified circuit diagram of a conventional network signal processing circuit.

In order to achieve the above objectives and effects, the technical means and its construction adopted in the present invention are described in detail in the preferred embodiment of the present invention, and the structure and function are as follows.

Please refer to the first, second and third figures, which are respectively a simplified circuit diagram, a block diagram and a block diagram of a preferred embodiment. It can be clearly seen from the figure that the filtering of the network signal is filtered. The circuit includes a processing circuit 1 disposed on the circuit board 10, and has a predetermined electronic component and circuit layout such as a resistor 101, a first capacitor 102, and a second capacitor 103 on the circuit board 10, and the processing circuit 1 has At least one circuit channel 13 connected between the first connection end 11 and the second connection end 12 and the first connection end 11 and the second connection end 12, and a common mode inductance connected in parallel between any two adjacent circuit channels 13 a unit 2, and a coupling capacitor 14 is connected in series on the side of the common circuit inductor unit 2 adjacent to the common mode inductor unit 2, and an autotransformer 15 and an autotransformer are respectively connected in parallel between any two adjacent circuit channels 13 A first coil winding and a second coil winding (not shown) are wound around the iron core of the 15th, and the first wiring 151 and the second wiring 152 are extended on the first coil winding or the second coil winding. The first wiring 151 is connected in series to the resistor 101 and the first capacitor 102 on the circuit board 10, and then connected to the ground terminal 10a for grounding, and the second wiring 152 is connected in series to the second capacitor 103 on the circuit board 10, and then connected. Grounding to ground terminal 10b to form a filtering noise circuit for the network signal of the present invention.

Moreover, the first connection end 11 of the processing circuit 1 is electrically connected to the terminal group of the network connector 4, and each of the second connection ends 12 is electrically connected to the pin group of the network chip 3, respectively. The network chip 3 and the processing circuit 1 are preferably disposed on the circuit board 10 and connected to the external network connector 4 by the circuit board 10. However, in actual applications, the network connector 4 can also be processed. The circuit 1 is disposed on the circuit board 10, or the circuit board 10 can be further disposed inside the network connector 4, and then connected to the network chip 3 on the external circuit board by the circuit board 10; In order to further provide a power supply (such as a dry battery, a rechargeable battery, a lithium battery or a button type battery, or a power source that can be connected to an external mains through a power line), and the processing circuit 1 is provided by the circuit board 10. The power required for the network chip 3 and the network connector 4, etc., but the manner in which the network chip 3 and the network connector 4 are connected and arranged is in the prior art, and the composition of the details It is not the creation point of this case, so it is no longer a problem. .

However, the first connection end 11 on the side of the processing circuit 1 has eight pins on the first connection end, which are respectively MX0+, MX0-, MX1+, MX1-, MX2+, MX2-, MX3+, and MX3-, and are processed in the circuit. 1 The first connection end 11 on the other side has eight pins, and each pin is MD0+, MD0-, MD1+, MD1-, MD2+, MD2-, MD3+ and MD3-, respectively, and is only used as a pin. The number, each number can still be transformed according to the actual design needs.

When the processing circuit 1 of the present invention is actually applied, if the terminal group of the network connector 4 receives the instantaneous high voltage or glitch generated by the external lightning strike during the transmission of the network signal, the network connector 4 can be transmitted to the processing. The circuit circuits 13 of the circuit 1 are stepped down by the coupling action of the respective coupling transformers 15, and the voltages 101 and the first capacitors 102 connected in series through the first wiring 151 are transmitted to the ground terminal 10a for removal. However, since the second wiring 152 of the autotransformer 15 is connected in series with the second capacitor 103 for grounding, the processing circuit 1 does not have the function of lightning protection, but the processing circuit 1 can be connected through the autotransformer 15 to extend the first. The wiring 151 and the second wiring 152 are respectively connected in series with the resistor 101 of the circuit board 10, and the first capacitor 102 and the second capacitor 103 are connected to the ground terminals 10a, 10b for circuit design to be applied to the existing circuit board 10 conforming to the PoE power supply specification. Moreover, the processing circuit 1 does not need to cooperate with the electronic component changing circuit layout provided on the circuit board 10 to achieve the purpose of reducing the production cost, and has more practical and applicable effects.

The capacitance values of the coupling capacitors 14 respectively connected in series with the processing circuit 1 on each circuit channel 13 may be between 0.03 μF and 1.0 μF μF, and the capacitance value of the preferred implementation may be 0.1 μF, and the processing circuit 1 is located at any position. The inductance of the autotransformer 15 connected in parallel between two adjacent circuit channels 13 may be between 30 μH and 350 μH, and the DC resistance (DCR) may be between 0.5 and 2 ohms. 80μH, DC resistance (DCR) is 1 ohm.

When the network connector 4 receives interference such as external electromagnetic waves (EMI) or noise during the transmission of the network signal, in order to improve the capacitance value or the inductance value of each of the coupling capacitor 14 and the autotransformer 15 If the noise is too large or too small, the noise contained in the network signal is not easily filtered, and the filtering can be performed by each common mode inductor unit 2. The noise in each circuit channel 13 is removed from the coupling capacitor 14 and the autotransformer 15, and then removed through the resistor 101 on the circuit board 10, the first capacitor 102, and the ground terminals 10a and 10b of the second capacitor 103. To filter out the noise interference in each circuit channel 13, and meet the requirements of the detection specification (IEEE regulations), the network signal can be stably transmitted to the network chip 3 through the circuit channel 13 for processing to avoid signal transmission. In the process, instability or interruption occurs, which makes the quality of network signal transmission more stable.

Furthermore, the inductance of the common mode inductor unit 2 can be between 90 ohms and 1000 ohms, and when the network signal is transmitted according to each circuit channel 13 of the processing circuit 1, the noise of the signals in the various frequency bands is different. The common mode inductor unit 2 preferably has an inductance value of 800 ohms, and during the signal transmission process of each circuit channel 13, if other signals enter and generate electromagnetic waves or noise, etc., The mode inductor unit 2 uses an inductance value of about 800 ohms to filter out the noise contained in the network signal. However, in practical applications, the inductance value can be adjusted according to the actual application or circuit design to improve the high frequency network. The stability of the signal transmission.

Therefore, the present invention is mainly disposed on the circuit board 10 for the processing circuit 1, and a circuit channel 13 is connected between the first connection end 11 and the second connection end 12, and any two adjacent circuit channels 13 are connected. The common mode inductor unit 2 is connected in parallel, and the coupling capacitor 14 and the adjacent circuit channel 13 are respectively connected in parallel with the autotransformer 15 in each circuit channel 13, and the autotransformer 15 is connected and extended. A wiring 151 and a second wiring 152 are respectively connected in series with the resistor 101 on the circuit board 10 and the first capacitor 102 and the second capacitor 103 are grounded for protection. The circuit design of the autotransformer 15 of the processing circuit 1 can be applied. It does not need to be equipped on the existing circuit board 10 that meets the PoE power supply specifications. The electronic component on the circuit board 10 changes the circuit layout to achieve the purpose of reducing the production cost, and has more practical and applicable effects.

The above detailed description is intended to illustrate a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and other equivalents and modifications may be made without departing from the spirit of the invention. Changes are to be included in the scope of patents covered by this creation.

In summary, the above-mentioned network signal filtering noise circuit can achieve its efficacy and purpose. Therefore, this creation is a practical and excellent creation, which is in line with the application requirements of the new patent. To apply, I hope that the trial committee will grant this case as soon as possible to protect the hard work of the new creators. If there is any doubt in the bureau, please do not hesitate to give a letter, and the new creators will try their best to cooperate with them.

1‧‧‧Processing circuit

10‧‧‧ boards

10a‧‧‧ Grounding

10b‧‧‧ Grounding

101‧‧‧resistance

102‧‧‧first capacitor

103‧‧‧second capacitor

11‧‧‧First connection

12‧‧‧second connection

13‧‧‧Circuit channel

14‧‧‧Coupling capacitor

15‧‧‧Autotransformer

151‧‧‧First wiring

152‧‧‧second wiring

2‧‧‧Common mode inductance unit

Claims (2)

A filtering circuit for filtering a network signal includes a processing circuit disposed on a circuit board, wherein the processing circuit is electrically connected to a first connection end of the preset network connector and electrically connected to the preset a second connection end of the network chip, and at least one circuit channel is connected between the first connection end and the second connection end, and a common mode inductance unit is connected in parallel between any two adjacent circuit channels, and then each circuit A coupling capacitor is connected in series adjacent to the common mode inductor unit on the channel, and an autotransformer is connected in parallel between any two adjacent circuit channels, and the first connection of the autotransformer is connected in series with the circuit board. The resistor and the first capacitor and the second wiring are connected in series with a second capacitor on the circuit board. For example, the filtering signal of the network signal according to the first aspect of the patent application, wherein the circuit board has a resistor, a first capacitor and a second capacitor, and the first wiring series resistance of the autotransformer and the first After a capacitor is connected to the ground for grounding, and the second wiring is connected to the second capacitor and then connected to the ground for grounding.