WO2016197640A1

WO2016197640A1 - Anti-noise interference system

Info

Publication number: WO2016197640A1
Application number: PCT/CN2016/075972
Authority: WO
Inventors: 徐新林
Original assignee: 中兴通讯股份有限公司
Priority date: 2015-06-08
Filing date: 2016-03-09
Publication date: 2016-12-15
Also published as: CN204993316U

Abstract

Disclosed is an anti-noise interference system. The system comprises: a first digital signal transceiving device, a second digital signal transceiving device, a first impedance match device, a passive filtering device and a first compensation device. One end of the first impedance match device is connected to the first digital signal transceiving device, and the other end of the first impedance match device is connected to the second digital signal transceiving device. One end of the passive filtering device is connected to the other end of the first impedance match device. The first compensation device comprises: a first resistor and a first capacitor, wherein one end of the first resistor is connected to one end of the first capacitor, the other end of the first resistor is connected to the one end of the first impedance match device, and the other end of the first capacitor is connected to the other end of the first impedance match device.

Description

Anti-noise interference system

Technical field

This application relates to, but is not limited to, power electronics technology.

Background technique

As switching power supplies are widely used in almost all electronic devices, the electromagnetic radiation of switching power supplies also affects the transmission quality of digital signals in the circuit.

1 is a schematic structural view of a digital signal transmission system of the related art. In the digital signal transmission process, in order to reduce the high frequency interference of the switching power supply, as shown in FIG. 1, an impedance matching device is usually connected in series between the first digital signal transmitting and receiving device 11 and the second digital signal transmitting and receiving device 12, that is, The first impedance matching device 13 is connected to a passive filter device 14 on the connection between the impedance matching device and the second digital signal transceiver device 12, wherein the passive filter device 14 can be a capacitor. One end is connected to the line between the impedance matching device and a digital signal transceiving device, and the other end is grounded, so that the capacitor with a small capacitance is used for filtering.

Summary of the invention

The following is an overview of the topics detailed in this document. This Summary is not intended to limit the scope of the claims.

In the above related art, the switching power supply in the vicinity of the digital signal generates a relatively low interference frequency, and the capacitance with a small capacitance value often does not filter. However, the capacitance with a larger capacitance value causes the rising or falling edge of the signal. The slowing down, even the waveform distortion is distorted, so that when the medium and low frequency interference is filtered out by increasing the capacitance value in the passive filtering device, the signal rise time and the fall time cannot satisfy the signal transmission requirement.

This paper provides an anti-noise interference system to solve the problem that the signal rise time and fall time can not meet the signal transmission requirements when the medium and low frequency interference is filtered out by increasing the capacitance value of the passive filter device.

An anti-noise system that includes:

a first digital signal transmitting and receiving device, a second digital signal transmitting and receiving device, a first impedance matching device, a passive filtering device, and a first compensating device, wherein one end of the first impedance matching device is connected to the first digital signal transmitting and receiving device, The other end of the first impedance matching device is connected to the second digital signal transmitting and receiving device, and one end of the passive filtering device is connected to the other end of the first impedance matching device, wherein

The first compensation device includes: a first resistor and a first capacitor, one end of the first resistor is connected to one end of the first capacitor, and the other end of the first resistor is connected to the first impedance matching device One end of the first capacitor is connected to the other end of the first impedance matching device.

Optionally, the system further includes: a second compensation device and a second impedance matching device, wherein the second compensation device and the second impedance matching device are connected in parallel, and one end of the second impedance matching device and the first Two digital signal transceiving devices are connected, and the other end of the second impedance matching device is connected to the first impedance matching device.

Optionally, the second compensation device includes: a second resistor and a second capacitor, one end of the second resistor is connected to one end of the second capacitor, and the other end of the second resistor is opposite to the first One end of the two impedance matching device is connected, and the other end of the second capacitor is connected to the other end of the second impedance matching device.

Optionally, the passive filtering device includes: a third capacitor, one end of the third capacitor is connected to the first impedance matching device, and the other end of the third capacitor is grounded.

Optionally, a capacitance of the third capacitor is smaller than a capacitance of the first capacitor, and a capacitance of the third capacitor is smaller than a capacitance of the second capacitor.

Other aspects will be apparent upon reading and understanding the drawings and detailed description.

BRIEF abstract

1 is a schematic structural diagram of a digital signal transmission system of the related art;

2 is a schematic structural diagram of Embodiment 1 of an anti-noise interference system according to the present invention;

FIG. 3 is a schematic structural diagram of Embodiment 2 of the anti-noise interference system of the present invention.

Embodiments of the invention

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, in the case of no conflict, the features in the embodiments and the embodiments in the present application may be arbitrarily combined with each other.

2 is a schematic structural diagram of Embodiment 1 of the anti-noise interference system of the present invention. As shown in FIG. 2, the anti-noise interference system provided by the embodiment of the present invention can be applied to a digital signal transmission scenario, and the anti-noise interference system can include: a digital signal transceiving device 11, a second digital signal transceiving device 12, a first impedance matching device 13, a passive filtering device 14, and a first compensating device 15, one end of the first impedance matching device 13 and the first number The signal transceiving device 11 is connected, the other end of the first impedance matching device 13 is connected to the second digital signal transceiving device 12, and one end of the passive filtering device 14 and the other end of the first impedance matching device 13 Connected, among them,

The first compensating device 15 is connected in parallel with the first impedance matching device 13. The first compensating device 15 includes: a first resistor R1 and a first capacitor C1, one end of the first resistor R1 and the first One end of a capacitor C1 is connected, and the other end of the first resistor R1 is connected to one end of the first impedance matching device 13. The other end of the first capacitor C1 is connected to the other end of the first impedance matching device 13. connection.

In this embodiment, the first digital signal transmitting and receiving device 11 is a device that generates a digital signal; and the second digital signal transmitting and receiving device 12 is a device that receives the digital signal.

And during the rising of the digital signal signal, causing the digital signal to charge the passive filtering device by the first compensation device; during the digital signal being held at a high level, the digital signal passes the first An impedance matching device is transmitted to the second digital signal transceiver; during the falling of the digital signal, the passive filtering device is discharged by the first compensation device; the digital signal is held during a low level, the digital A signal is transmitted to the second digital signal transceiving device via the first impedance matching device.

For example, the anti-noise interference system may include: a first digital signal transmitting and receiving device 11, that is, a digital signal transmitting device, a second digital signal transmitting and receiving device 12, that is, a digital signal receiving device, and a first The first matching device 15 includes a first resistor R1 and a first capacitor C1, One end of a resistor R1 is connected to one end of the first capacitor C1, the other end of the first resistor R1 is connected to the digital signal transmitting device 11, and the other end of the first capacitor C1 is connected to the digital signal receiving device 12, the third One end of the capacitor C3 is connected to the other end of the first capacitor C1, and the other end of the third capacitor C3 is grounded.

In this embodiment, the anti-noise interference system includes: a first digital signal transmitting and receiving device 11, a second digital signal transmitting and receiving device 12, a first impedance matching device 13, a passive filtering device 14, and a first compensating device 15, One end of the first impedance matching device 13 is connected to the first digital signal transmitting and receiving device 11, and the other end of the first impedance matching device 13 is connected to the second digital signal transmitting and receiving device 12, and the passive filtering device 14 is connected. One end is connected to the other end of the first impedance matching device 13, wherein the first digital signal transmitting and receiving device 11 is a device for generating a digital signal; and the second digital signal transmitting and receiving device 12 is for receiving the digital signal. The first compensating device 15 includes: a first resistor R1 and a first capacitor C1, one end of the first resistor R1 is connected to one end of the first capacitor C1, and the other end of the first resistor R1 is Connected to one end of the first impedance matching device 13, the other end of the first capacitor C1 is connected to the other end of the first impedance matching device 13. It avoids the interference of low frequency and low frequency in digital signal transmission, and further realizes that the signal rise time and fall time can meet the requirements of signal transmission when the filter capacitor is increased. In the present embodiment, the digital signal is generated and output by the digital signal transmitting means, and is received by the digital signal receiving means via the transmission line. The resistance of the first resistor R1 in the first compensation device 15 is small, and is generally selected to be several tens of milliohms, mainly to prevent signal oscillation, and the actual circuit can be replaced by the ESR of the capacitor. The signal is generated and output by the digital signal transmitting device, and the impedance of the third resistor R3 is higher than the first resistor R1 and the first capacitor C1 during the rising time of the low-level digital signal to the high-level digital signal. The impedance of the compensation device 15 is much larger, and the signal charges the passive filter device 14, that is, the third capacitor C3, through the first resistor R1 and the first capacitor C1. At this time, the signal instantaneously generates a relatively large current, and the third capacitor C3 is charged. Fast completion, so that the digital signal rise time meets the signal quality requirements of signal transmission. During the process of keeping the digital signal high, the impedance of the third resistor R3 is much smaller than the impedance of the first compensation device 15, so that the digital signal can be transmitted to the third capacitor C3 through the third resistor R3, thereby maintaining the third capacitor C3. Is high. When the digital signal jumps from a high level to a low level, the impedance of the third resistor R3 is much larger than the resistance of the first compensating device 15. The digital signal can be discharged to the third capacitor C3 through the first compensating device 15, and the digital signal instantaneously generates a relatively large current, and the discharging of the third capacitor C3 can be completed quickly, thereby realizing the digital signal falling time to satisfy the digital signal. Signal quality requirements for transmission. During the process of keeping the digital signal low, the impedance of the third resistor R3 is much smaller than the impedance of the first compensating device 15, and the digital signal maintains the third capacitor C3 at a low level through the third resistor R3. During the entire transmission of the digital signal, the intermediate low frequency interference signal can be filtered out through the third resistor R3 and the third capacitor C3 having a larger capacitance value.

The embodiment of the present invention further provides an anti-noise interference system. Based on the foregoing embodiment, as shown in FIG. 3, the anti-noise interference system may further include: a second compensation device 16 and a second impedance matching device 17, The second compensating device 16 and the second impedance matching device 17 are connected in parallel, one end of the second impedance matching device 17 is connected to the second digital signal transceiving device 12, and the second impedance matching device 17 is further connected. One end is connected to the first impedance matching device 13.

3 is a schematic structural diagram of Embodiment 2 of the anti-noise interference system of the present invention. As shown in FIG. 3, based on the foregoing embodiment, the anti-noise interference system may include: a first digital signal transceiver device 11 and a second digital signal. The transceiver device 12, the third capacitor C3 (ie, the passive filter device 14), the third resistor R3 (ie, the first impedance matching device 13), the first compensation device 15, and the fourth resistor R4 (ie, the second impedance matching device 17) And a second compensating device 16, the third resistor R3 is connected in parallel with the first compensating device 15, and the fourth resistor R4 is connected in parallel with the second compensating device. The first compensating device 15 may include: a first resistor R1 and a first capacitor C1, One end of the first resistor R1 is connected to one end of the first capacitor C1, the other end of the first resistor R1 is connected to the first digital signal transceiver device 11, and the other end of the first capacitor C1 is connected to one end of the fourth resistor R4. The other end of the fourth resistor R4 is connected to the second digital signal transceiver 12, and the second compensation device 16 may include: a second resistor R2 and a second capacitor C2, the second resistor R2 and the second capacitor C2 is connected. One end of the third capacitor C3 is connected to the other end of the first capacitor C1, and the other end of the third capacitor C3 is grounded. The capacitance of the third capacitor C3 is smaller than the capacitance of the first capacitor C1. The capacitance of the third capacitor C3 is smaller than the capacitance of the second capacitor C2.

The difference between the embodiment and the embodiment shown in FIG. 2 is that in the embodiment, the first digital signal transmitting and receiving device 11 and the second digital signal transmitting and receiving device 12 are both digital signal transmitting and receiving devices, and can output digital signals or digital signals. . The device is suitable for the case of bidirectional transmission of signals. When the first digital signal transceiving device 11 outputs a digital signal, the process of transmitting the digital signal to point A is as shown in FIG. 2 In the illustrated embodiment, the digital signal can be transmitted to the second digital signal transmitting and receiving device 12 through the second compensating device 16 because the impedance of the second compensating device 16 is much smaller than the fourth resistor R4 during the rise time of point A. When the digital signal remains at the high point A, since the impedance of the fourth resistor R4 is much smaller than the second compensating device 16, the digital signal is transmitted to the second digital signal transmitting and receiving device 12 through the fourth resistor R4. When the digital signal falls from a high level to a low level at point A, the digital signal at the second digital signal transmitting and receiving device 12 rapidly drops by following the point A by the second compensating means 16. During the period in which the point A is kept low, the digital signal at the second digital signal transmitting and receiving device 12 is kept in line with the potential of the point A through the fourth resistor R4. When the second digital signal transmitting and receiving device 12, that is, generates a digital signal, the transmission process of the digital signal is reversed from the above process. During the whole digital signal transmission, the low-frequency interference signal can be filtered out through the third resistor R3, the fourth resistor R4, and the third capacitor C3 with a larger capacitance.

Industrial applicability

Through the embodiments of the present invention, the interference of the low frequency and the low frequency in the digital signal transmission is avoided, and the signal rise time and the fall time can still satisfy the requirements of the signal transmission when the filter capacitor is increased.

Claims

An anti-noise interference system, comprising: a first digital signal transceiving device, a second digital signal transceiving device, a first impedance matching device, a passive filtering device and a first compensating device, one end of the first impedance matching device The first digital signal transceiving device is connected, the other end of the first impedance matching device is connected to the second digital signal transceiving device, and one end of the passive filtering device is connected to the other end of the first impedance matching device. ,among them,

The first compensation device includes: a first resistor and a first capacitor, one end of the first resistor is connected to one end of the first capacitor, and the other end of the first resistor is connected to the first impedance matching device One end of the first capacitor is connected to the other end of the first impedance matching device.
The system according to claim 1, further comprising: a second compensating means and a second impedance matching means, said second compensating means and said second impedance matching means being connected in parallel, one end of said second impedance matching means The second digital signal transmitting and receiving device is connected, and the other end of the second impedance matching device is connected to the first impedance matching device.
The system according to claim 2, wherein said second compensating means comprises: a second resistor and a second capacitor, one end of said second resistor being connected to one end of said second capacitor, said second resistor The other end is connected to one end of the second impedance matching device, and the other end of the second capacitor is connected to the other end of the second impedance matching device.
The system according to claim 3, wherein said passive filtering means comprises: a third capacitor, one end of said third capacitor being connected to said first impedance matching means, and the other end of said third capacitor being grounded .
The system according to claim 4, wherein a capacitance of the third capacitor is smaller than a capacitance of the first capacitor, and a capacitance of the third capacitor is smaller than a capacitance of the second capacitor.