Low-frequency digital signal transmission anti-interference circuit and circuit protection board

Abstract

The utility model provides a low-frequency digital signal transmission anti-interference circuit and a circuit protection board. The low-frequency digital signal transmission anti-interference circuit comprises an input module, a transmission module and an output module, the input module comprises an input anti-interference unit, and the output module comprises an output anti-interference unit; according to the invention, through signal anti-logic transmission, the transmitted high level can be independent, and the amplitude of the transmitted signal is improved, so that the interference capability is enhanced. When the low-frequency digital signal transmission anti-interference circuit receives a high-level signal transmitted by a superior circuit, the received interference signal can be discharged to a ground loop through an input anti-interference module; when the low-frequency digital signal transmission anti-interference circuit receives a low-level signal transmitted by a superior circuit, the anti-interference capability of the circuit can be improved through the output anti-interference module. The output module further comprises a voltage dividing module which is used for improving the opening threshold of the output module. The circuit is simple in design and low in cost.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of circuit design transmission, in particular to a low-frequency digital signal transmission anti-interference circuit and a circuit protection board. BACKGROUND

[0002] With the rapid development of science and technology and the improvement of people's living standards, electronic products are becoming more and more popular in daily life and have become an indispensable tool for people. The invention of digital signals greatly improves the reliability of electronic products, enabling digital circuits to play an important role in circuit design and promoting the popularization and diversification of intelligent devices.

[0003] In the design of modern product interconnection, I2C, UART, SPI and PWM interfaces are widely used. These technologies not only support efficient communication between devices, but also simplify the system design process. Many chip manufacturers continue to integrate these mature interface technologies into various integrated circuit (IC) design schemes to meet market demand for high performance and high reliability.

[0004] However, as the requirement for electromagnetic compatibility (EMC) reliability of electronic products increases, the challenge of multiple PCBA board-level interconnection becomes more and more obvious. Long-distance communication lines are extremely susceptible to external electromagnetic interference, resulting in signal distortion and affecting the overall performance of the device. Traditional anti-interference design usually requires complex layout and additional shielding measures, which is relatively high in cost, making it not economical and practical for large-scale electronic product applications. CONTENT OF THE INVENTION

[0005] To solve the above technical problems, the application provides a low-frequency digital signal transmission anti-interference circuit and a circuit protection board, which simplifies the anti-interference circuit design and improves the stability and reliability of signal transmission.

[0006] In a first aspect, the application provides a low-frequency digital signal transmission anti-interference circuit, which comprises an input module, a transmission module and an output module.

[0007] The input module is used to receive digital signals transmitted by the upper circuit and output anti-level digital signals to the transmission module.

[0008] The input module includes an input anti-interference unit, and the transmission module input end is connected to the input anti-interference unit to receive the anti-level digital signals and output to the output module.

[0009] The output module includes an output anti-interference unit, and the output anti-interference unit is connected to the transmission module output end.

[0010] The output module further comprises a voltage division unit for improving the opening threshold of the output module.

[0011] The output module is used for receiving the inverted digital signal and outputting the anti-interference digital signal to a lower circuit.

[0012] The application can separate the transmitted high level and improve the signal amplitude of the transmission, thereby enhancing the interference ability. When the low-frequency digital signal transmission anti-interference circuit receives the high level signal transmitted by the upper circuit, the interference signal received can be discharged to the ground circuit through the transmission module combined with the input anti-interference module; when the low-frequency digital signal transmission anti-interference circuit receives the low level signal transmitted by the upper circuit, the anti-interference ability of the circuit can be improved through the transmission module combined with the output anti-interference module.

[0013] Further, the input module further comprises a resistor R5 and a resistor R6; the input anti-interference unit comprises a Mos tube Q1.

[0014] Further, the input module further comprises that the gate of the Mos tube Q1 is connected to the upper circuit through the resistor R5; the drain of the gate of the Mos tube Q1 is grounded; the source of the Mos tube Q1 is connected to the transmission module; and the resistor R4 is connected between the gate and the drain of the Mos tube Q1.

[0015] The input module comprises an input anti-interference unit, and the input anti-interference unit comprises a Mos tube Q1. Through the above connection design, the interference signal received on the transmission module can be discharged to the ground end, and it can be ensured that after the input module receives the digital signal transmitted by the upper circuit, the inverted digital signal is output to the transmission module.

[0016] Further, the transmission module comprises a signal transmission line bundle, and the length of the signal transmission line bundle ranges from 0.3 m to 1 m.

[0017] Further, the input end of the signal transmission line bundle is connected to the input anti-interference unit, and the output end of the signal transmission line bundle is connected to the output anti-interference unit.

[0018] The transmission module is located between the input module and the output module and plays a role of transition anti-interference.

[0019] Further, the output module further comprises a resistor R4, a triode Q2 and a direct current power supply VDD; the output anti-interference unit comprises a pull-up resistor R1 and a direct current power supply VCC; and the voltage division module comprises a resistor R2, a resistor R3 and a capacitor C2.

[0020] Further, the output module further comprises: a collector of the transistor Q2 is connected with the lower circuit and the direct current power supply VDD through the resistor R4; an emitter of the transistor Q2 is grounded; a base of the transistor Q2 is connected with the transmission module through a resistor; the direct current power supply VCC is connected with the transmission module through the pull-up resistor R1; and the capacitor C2 and the resistor R2 are connected between the emitter and the base of the transistor Q2.

[0021] The input module comprises an output anti-interference unit, the output anti-interference unit comprises a pull-up resistor R1, and the above-mentioned connection design can reduce the low-level interference signal received on the transmission module; the input module further comprises a voltage division unit, the input module is driven after voltage division through two resistors, so that the threshold of NPN opening is improved, and the anti-interference capability of the product is finally improved. The input module further comprises a transistor Q2, so that after the input module receives the inverted level digital signal of the transmission module, the digital signal can be output to the lower circuit.

[0022] In the second aspect, the application provides a circuit protection board, comprising: the low-frequency digital signal transmission anti-interference circuit and a circuit substrate, wherein the low-frequency digital signal transmission anti-interference circuit is integrated on the circuit substrate.

[0023] In summary, the application provides a low-frequency digital signal transmission anti-interference circuit and a circuit protection board, wherein the low-frequency digital signal transmission anti-interference circuit comprises: an input module, a transmission module and an output module; the input module comprises an input anti-interference unit, and the output module comprises an output anti-interference unit.

[0024] Compared with the prior art, the application has at least the following beneficial effects:

[0025] The application can separate the transmitted high level, improve the signal amplitude of transmission, and thus enhance the interference capability through signal inversion logic transmission. When the low-frequency digital signal transmission anti-interference circuit receives the high-level signal transmitted by the upper circuit, the interference signal received can be discharged to the ground circuit through the input anti-interference module; when the low-frequency digital signal transmission anti-interference circuit receives the low-level signal transmitted by the upper circuit, the anti-interference capability of the circuit can be improved through the output anti-interference module. Moreover, the output module further comprises a voltage division module for improving the opening threshold of the output module. The circuit is simple in design and low in cost. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a low-frequency digital signal transmission anti-interference circuit system diagram shown in the embodiment of the utility model.

[0027] Figure 2 It is a low-frequency digital signal transmission anti-interference circuit circuit diagram shown in the embodiment of the utility model.

[0028] Figure 3 This is a parameter scan diagram of VCC-OUTPUT shown in an embodiment of this utility model.

[0029] Figure 4 This is an actual waveform diagram of the WIRE harness shown in this embodiment of the utility model.

[0030] Figure 5 This is a waveform diagram of the input and output of the low-frequency digital signal transmission anti-interference circuit shown in an embodiment of this utility model. Detailed Implementation

[0031] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely...

[0032] These are some, but not all, embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without inventive effort should fall within the scope of protection of this application.

[0033] The following sections will provide detailed explanations.

[0034] The terms "first," "second," "third," and "number" in the specification, claims, and accompanying drawings of this application are as follows.

[0035] The use of "four" etc. is to distinguish different objects, not to describe a specific order. Furthermore, the term "comprising," and any variations thereof, is intended to cover non-exclusive inclusion. For example, a system that includes a series of modules and devices is not limited to those listed, but may optionally include modules and devices not listed, or may optionally include other modules and devices inherent to these systems.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] Example 1:

[0038] like Figure 1 As shown, this application proposes a low-frequency digital signal transmission anti-interference circuit, which includes an input module, a transmission module, and an output module.

[0039] The input module is used to receive digital signals transmitted from the upper-level circuit and output inverse-level digital signals to the transmission module.

[0040] The input module includes an input anti-interference unit, and the input terminal of the transmission module is connected to the input anti-interference unit to receive the inverse level digital signal and output it to the output module.

[0041] The output module includes an output anti-interference unit, which is connected to the output terminal of the transmission module.

[0042] The output module also includes a voltage divider unit for increasing the opening threshold of the output module.

[0043] The output module is used to receive the anti-level digital signal and output the interference-free digital signal to the next stage circuit.

[0044] As attached Figure 2 As shown, this is a specific low-frequency digital signal transmission anti-interference circuit in this embodiment.

[0045] In this embodiment of the present invention, optionally, the input module further includes: resistor R5 and resistor R6; the input anti-interference unit includes: MOSFET Q1.

[0046] In this embodiment of the present invention, optionally, the input module further includes: the gate of the MOSFET Q1 is connected to the upper-level circuit through a resistor R5; the drain of the gate of the MOSFET Q1 is grounded; the source of the MOSFET Q1 is connected to the transmission module; and the resistor R4 is connected between the gate and drain of the MOSFET Q1.

[0047] A MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) is a widely used semiconductor device in electronic circuits, primarily for switching and signal amplification. Its operating principle is based on the modulation of semiconductor materials by an electric field, offering advantages such as high input impedance and low power consumption.

[0048] In this embodiment, the input module further includes an AC power supply V2, whose positive terminal is connected to the upper-level circuit and whose negative terminal is grounded; used to simulate an interference source.

[0049] In this embodiment, the MOSFET used is an NMoS MOSFET.

[0050] In this embodiment of the present invention, optionally, the transmission module includes: a signal transmission harness, the length of which is 0.3m-1m; the input end of the signal transmission harness is connected to the input anti-interference unit, and the output end of the signal transmission harness is connected to the output anti-interference unit.

[0051] In the embodiment of the utility model, optionally, the transmission module further includes: capacitor C1, the capacitor C1 input end connects the signal transmission wire harness middle end, the capacitor C1 output end connects the alternating current power supply V1 anode, the alternating current power supply V1 cathode is grounded, be used for analog interference source.

[0052] In the embodiment of the utility model, optionally, the output module further includes: resistor R4, triode Q2 and direct current power supply VDD, the output anti-interference unit includes: pull-up resistor R1 and direct current power supply VCC, the voltage division module includes: resistor R2, resistor R3 and capacitor C2.

[0053] In the embodiment of the utility model, optionally, the output module further includes: the collector of triode Q2 is connected with the lower circuit and is connected with direct current power supply VDD through resistor R4, the emitter of triode Q2 is grounded, the base of triode Q2 is connected with the transmission module through resistance, direct current power supply VCC is connected with the transmission module through pull-up resistor R1, capacitor C2 and resistor R2 are connected between the emitter and base of triode Q2.

[0054] Triode is a kind of basic semiconductor device, is widely used in electronic circuit, mainly for signal amplification and switch control.Triode is divided into two main types: NPN type and PNP type.In the embodiment, the triode used is NPN triode.

[0055] In the embodiment, when INPUT is high level, it is low level on the middle WIRE wire harness.At this time, NMOS tube is in the on state, provides low impedance path (mohm level), and the interference received on WIRE wire is discharged to ground end, so that the output OUTPUT end can output high level with small interference.

[0056] In the embodiment, when INPUT is low, the level on WIRE wire is high, and the anti-interference ability is improved by the pull-up level of Sink end.At the same time, NPN circuit B pole is driven after being divided by two resistors, so as to improve the threshold of NPN opening, and finally improve the anti-interference ability of product.

[0057] In the embodiment, when INPUT is low level, Q1 is high resistance state, VCC is pulled up by R1, so that Q2 triode remains in the on state, so that OUTPUT is low level.For Q2 triode, the input level of NPN triode is raised by the circuit composed of R2 and R3.

[0058] As Figure 3The figure shows the parameter scanning diagram of VCC-OUTPUT. It represents the output voltage of OUTPUT under different VCC voltage. When the VCC voltage is about 1.92V, the NPN output is less than 0.3V, which is low level. It can be considered that when the voltage on the WIRE wire bundle is greater than 2V, the OUTPUT output is low.

[0059] As Figure 4 The figure is the actual waveform diagram of the WIRE wire bundle, and the reason for the interference. The high level has a peak interference signal greater than 3V, and the low level is relatively stable (the effect of the NMOS circuit). As shown in the simulation above, the OUTPUT circuit will output low when the signal level on the WIRE wire bundle is greater than 2V, so it is ensured that the output is not interfered.

[0060] Figure 5 The figure is the waveform diagram of the input and output of the low-frequency digital signal transmission anti-interference circuit, and the red color is the Source end INPUT input signal and the blue color is the Sink end OUTPUT output signal.

[0061] It should be noted that the power supply VCC of the pull-up on the Source end is taken as an example of 5V here, and in fact it can be set according to the peak-to-peak value of the interference signal, the frequency of the transmission signal, and the conduction threshold of the NPN transistor. The circuit has relatively high flexibility.

[0062] Embodiment two:

[0063] The application provides a circuit protection board, which comprises the low-frequency digital signal transmission anti-interference circuit in the first aspect and a circuit substrate, and the low-frequency digital signal transmission anti-interference circuit is integrated on the circuit substrate.

[0064] In summary, the application provides a low-frequency digital signal transmission anti-interference circuit and a circuit protection board, wherein the low-frequency digital signal transmission anti-interference circuit comprises an input module, a transmission module and an output module; the input module comprises an input anti-interference unit, the output module comprises an output anti-interference unit, and the output module further comprises a voltage division module.

[0065] The application can separate the transmission high level by signal inversion logic transmission, improve the signal amplitude of transmission, and thus enhance the interference ability. When the low-frequency digital signal transmission anti-interference circuit receives a high level signal transmitted by a superior circuit, the received interference signal can be discharged to the ground circuit through the input anti-interference module; when the low-frequency digital signal transmission anti-interference circuit receives a low level signal transmitted by a superior circuit, the anti-interference ability of the circuit can be improved through the output anti-interference module. Moreover, the output module further comprises a voltage division module for improving the opening threshold of the output module. The circuit is simple in design and low in cost.

[0066] In several embodiments provided in the present application, it can be understood that each block in the flowchart or block diagram can represent a module, a segment or a portion of code which includes one or more executable instructions for implementing the specified logic function. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figure. For example, two blocks noted in succession can in fact be executed substantially concurrently or in the reverse order, depending on the functionality involved.

[0067] The functions described above if implemented in software can be stored in a computer readable storage medium. Based on the understanding of the above, the technical solutions of the present application or the parts of the technical solutions which are essential or make contributions to the prior art or the parts of the technical solutions can be embodied in the form of software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing an electronic device to execute all or part of the steps of the method described in the embodiments of the present application. The storage medium mentioned above includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk and other various media which can store program codes.

[0068] The specific embodiments described above further illustrate the purposes, technical solutions and beneficial effects of the present application. It should be understood that the above description is only for specific embodiments of the present application and is not intended to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A low frequency digital signal transmission anti-jamming circuit, characterized in that, The low-frequency digital signal transmission anti-interference circuit comprises an input module, a transmission module and an output module. The input module is configured to receive a digital signal transmitted by a superior circuit and output an inverted level digital signal to the transmission module. The input module comprises an input anti-interference unit, the input end of the transmission module is connected to the input anti-interference unit, the inverted level digital signal is received and output to the output module. The output module comprises an output anti-interference unit, the output anti-interference unit is connected to the output end of the transmission module. The output module further comprises a voltage dividing unit for improving the opening threshold of the output module. The output module is configured to receive the inverted level digital signal and output an anti-interference digital signal to a subordinate circuit.

2. The low frequency digital signal transmission anti-jamming circuit according to claim 1, characterized in that, The input module further comprises a resistor R5 and a resistor R6, and the input anti-interference unit comprises a Mos transistor Q1.

3. The low frequency digital signal transmission anti-jamming circuit according to claim 2, wherein, The input module further comprises that the gate of the Mos transistor Q1 is connected to the superior circuit through the resistor R5, the drain of the gate of the Mos transistor Q1 is grounded, the source of the Mos transistor Q1 is connected to the transmission module, and the resistor R4 is connected between the gate and the drain of the Mos transistor Q1.

4. The low frequency digital signal transmission anti-jamming circuit of claim 1, wherein, The transmission module comprises a signal transmission wire harness, and the length of the signal transmission wire harness ranges from 0.3 m to 1 m.

5. The low frequency digital signal transmission anti-jamming circuit according to claim 4, characterized in that, The transmission module comprises that the input end of the signal transmission wire harness is connected to the input anti-interference unit, and the output end of the signal transmission wire harness is connected to the output anti-interference unit.

6. The low frequency digital signal transmission anti-jamming circuit of claim 1, wherein, The output module further comprises a resistor R4, a triode Q2 and a direct current power supply VDD, the output anti-interference unit comprises a pull-up resistor R1 and a direct current power supply VCC, and the voltage dividing unit comprises a resistor R2, a resistor R3 and a capacitor C2.

7. The low frequency digital signal transmission anti-jamming circuit according to claim 6, wherein, The output module further comprises that the collector of the triode Q2 is connected to the subordinate circuit and connected to the direct current power supply VDD through the resistor R4, the emitter of the triode Q2 is grounded, the base of the triode Q2 is connected to the transmission module through a resistor, the direct current power supply VCC is connected to the transmission module through the pull-up resistor R1, and the capacitor C2 and the resistor R2 are connected between the emitter and the base of the triode Q2.

8. A circuit protection board, characterized by The circuit protection board comprises the low-frequency digital signal transmission anti-interference circuit according to any one of claims 1-7 and a circuit substrate, and the low-frequency digital signal transmission anti-interference circuit is integrated on the circuit substrate.

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