PCB test system capable of eliminating system ground noise interference

Abstract

The utility model discloses a PCB circuit board test system capable of eliminating system ground noise interference, comprising a main PCB circuit board and N slave PCB circuit boards, the main PCB circuit board comprises a main power supply port, a first test voltage signal input port, a second test voltage signal access port, a main PCB circuit board ground terminal and a common mode voltage elimination module, the slave PCB circuit board comprises a slave power supply port, a test voltage signal output port and a slave PCB circuit board grounding end. A test voltage signal of the slave PCB is connected to a first test voltage signal input port of the master PCB, and a grounding end of the slave PCB is connected to a second test voltage signal input port of the master PCB. And the interference of the common-mode voltage between the ground ends of the main PCB and each slave PCB can be eliminated through a common-mode voltage elimination module connected with the first test voltage signal input port and the second test voltage signal input port.

Description

TECHNICAL FIELD

[0001] The utility model relates to PCB circuit test technical field especially relates to a kind of PCB circuit board test systems of system ground noise interference can be eliminated. BACKGROUND

[0002] In the PCB test system composed of multiple circuit boards, the noise interference problem between grounds (voltage reference points) is a common challenge. This noise interference is usually caused by the following reasons: the existence of resistance in the ground line of cable connection, wire length and unevenness, resulting in the ground potential between each circuit board not being completely the same, when the ground potential is inconsistent, a current loop can be formed, which in turn causes noise interference; when transmitting signals, cables can introduce certain resistance and inductance effects, which can cause signal distortion or waveform distortion, especially in the case of high frequency or small signal, the parasitic effects of the cable itself can be more obvious; since multiple circuit boards are connected by cables, the ground line can form a loop, especially when the signal path is long. This loop can cause ground current instability, thereby introducing noise and affecting the accuracy of measurement. When performing precision measurements, the influence of noise can cause significant errors, especially when measuring small signals.

[0003] Therefore, there is a need for a new solution. SUMMARY

[0004] The main purpose of the utility model is to solve the problem of noise caused by the resistance and inductance of cables in the prior art, by providing a PCB circuit board test system that can eliminate system ground noise interference.

[0005] To achieve the above purpose, the utility model provides a kind of PCB circuit board test systems of system ground noise interference can be eliminated, it includes main PCB circuit board and N from PCB circuit board, wherein, N is greater than or equal to 1 positive integer, the main PCB circuit board includes main power port, first test voltage signal input port, second test voltage signal access port, main PCB circuit board ground and common mode voltage elimination module, every from PCB circuit board includes from power port, test voltage signal output port and from PCB circuit board ground, the main power port is connected with the from power port of every from PCB circuit board, the first test voltage signal input port is connected with the test voltage signal output port of every from PCB circuit board, the second test voltage signal access port and the main PCB circuit board ground are connected with the from PCB circuit board ground of every from PCB circuit board, and the common mode voltage elimination module is connected with the first test voltage signal input port and the second test voltage signal access port.

[0006] In the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model, when N is equal to 1, the common mode voltage elimination module comprises a differential amplifier, the first test voltage signal input port is connected with the positive input end of the differential amplifier, and the second test voltage signal access port is connected with the reverse input end of the differential amplifier.

[0007] In the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model, when N is greater than 1, the common mode voltage elimination module further comprises a first line selection unit and a second line selection unit, the first test voltage signal input port is connected with the input end of the first line selection unit, the output end of the first line selection unit is connected with the positive input end of the differential amplifier, the second test voltage signal access port is connected with the input end of the second line selection unit, and the output end of the second line selection unit is connected with the reverse input end of the differential amplifier.

[0008] In the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model, the first line selection unit and the second line selection unit are multi-way switches.

[0009] The PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model has the following beneficial effects: in the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model, the test voltage signal of each slave PCB circuit board is connected with the first test voltage signal input port of the master PCB circuit board, the ground end of each slave PCB circuit board is connected with the second test voltage signal input port of the master PCB circuit board, and the common mode voltage elimination module connected with the first test voltage signal input port and the second test voltage signal input port can eliminate the interference of the common mode voltage between the ground (voltage reference point) of the master PCB circuit board and each slave PCB circuit board. BRIEF DESCRIPTION OF DRAWINGS

[0010] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are only the embodiments of the utility model, and for the ordinary skilled in the art, other drawings can be obtained according to the provided drawings without paying creative labor:

[0011] Figure 1 The principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model is shown;

[0012] Figure 2As shown in the principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the first embodiment of the utility model, N is equal to 1.

[0013] Figure 3 As shown in the principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the second embodiment of the utility model, N is greater than 1. DETAILED DESCRIPTION

[0014] In order to facilitate the understanding of the utility model, the utility model will be described more fully below with reference to the relevant drawings. The drawings show typical embodiments of the utility model. However, the utility model can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more thorough and comprehensive.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the utility model belongs. The terms used in the specification of the utility model herein are only for the purpose of describing specific embodiments and are not intended to limit the utility model.

[0016] Figure 1 As shown in the principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model. As shown in the principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the utility model, Figure 1The utility model provides a PCB circuit board test system, including main PCB circuit board 100 and N slave PCB circuit board 200, N is greater than or equal to 1 positive integer, through the main PCB circuit board 100 gathers every slave PCB circuit board 200's test voltage signal. Wherein, the main PCB circuit board 100 includes main power port 110, first test voltage signal input port 120, second test voltage signal access port 130, main PCB circuit board ground terminal 140 and common mode voltage elimination module 150, every slave PCB circuit board 200 includes slave power port 210, test voltage signal output port 220 and slave PCB circuit board ground terminal 230, the main power port 110 is connected every slave PCB circuit board 200's slave power port 210, first test voltage signal input port 120 is connected every slave PCB circuit board 200's test voltage signal output port 220, second test voltage signal access port 130 and main PCB circuit board ground terminal 140 are connected every slave PCB circuit board 200's slave PCB circuit board ground terminal 230, common mode voltage elimination module 150 is connected first test voltage signal input port 120 and second test voltage signal access port 130. Thus, every slave PCB circuit board's test voltage signal is accessed the first test voltage signal input port of main PCB circuit board, every slave PCB circuit board's ground terminal is accessed the second test voltage signal input port of main PCB circuit board, and then through the common mode voltage elimination module of first test voltage signal input port and second test voltage signal input port connection can eliminate the interference of common mode voltage between the ground (voltage reference point) between main PCB circuit board and every slave PCB circuit board.

[0017] The ground potential (i.e. reference voltage) of each circuit board can be inconsistent due to power supply noise or grounding problems between multiple circuit boards, resulting in ground potential differences. Such differences can cause common mode voltage, which in turn affects the accuracy of the signal. In the present embodiment, the master power port (110) provides power to multiple slave PCB circuit boards (200); the first test voltage signal input port (120) receives test voltage signals transmitted back from each slave PCB circuit board; the second test voltage signal access port (130) accesses the ground terminal of each slave PCB circuit board; and the common mode voltage elimination module (150) removes common mode voltage interference by connecting the first and second test voltage signal input ports. Thus, when the voltage signal of the slave PCB circuit board is accessed to the master PCB circuit board through the first test voltage signal input port, the ground terminal of the slave PCB circuit board is simultaneously accessed through the second test voltage signal access port. The common mode voltage elimination module processes these two signals to eliminate common mode noise, thereby ensuring accurate transmission of the signal. By eliminating common mode noise, it can be ensured that the test voltage signal of each slave PCB circuit board is not disturbed by the ground, increasing the accuracy and reliability of the test. Each slave PCB circuit board can be independently connected to the master PCB circuit board, and through the action of the common mode voltage elimination module, the system can be flexibly expanded and applied to different test requirements.

[0018] By adding a common mode voltage elimination module to the system, the present application effectively solves the problem of common mode voltage interference caused by ground differences. This design not only ensures the high precision and reliability of the test system, but also simplifies the complex debugging work in multi-PCB circuit board testing, and is an ideal solution for high-precision circuit testing requirements.

[0019] Figure 2 The principle diagram of the PCB circuit board test system capable of eliminating system ground noise interference provided by the first embodiment of the present application is shown, wherein N is equal to 1. As shown in Figure 2As shown, when N is equal to 1, the common mode voltage elimination module 150 includes a differential amplifier 160, the first test voltage signal input port 120 is connected to the positive input end of the differential amplifier 160, and the second test voltage signal access port 130 is connected to the negative input end of the differential amplifier 160. In this embodiment, the common mode voltage elimination module 150 uses a differential amplifier to realize the elimination of the common mode voltage. The differential amplifier is a circuit that can effectively amplify the difference between the two input signals while suppressing the common mode signal common to both. By connecting the first test voltage signal input port 120 to the positive input end of the differential amplifier, the voltage signal transmitted from the slave PCB circuit board is received; by connecting the second test voltage signal access port 130 to the negative input end of the differential amplifier, the ground signal or reference voltage signal received from the master PCB circuit board is received. In this way, when the voltage signal input difference between the master PCB circuit board and the slave PCB circuit board occurs, the differential amplifier amplifies and outputs the difference between the two, while suppressing the common mode noise caused by the difference in ground potential. Through the design of the differential amplifier, the noise caused by the difference in ground potential (i.e. the common mode voltage) is eliminated, thereby avoiding the interference of such noise on the signal test. Since the common mode voltage is suppressed, the effective part of the test signal can be transmitted more clearly and accurately, improving the measurement accuracy.

[0020] In this embodiment, the differential amplifier is used as the common mode voltage elimination module, which not only improves the anti-interference ability of the system, but also ensures the accuracy of signal transmission, and is an effective way to handle the ground problem and common mode noise in a multi-circuit board system.

[0021] Figure 3 As shown in the principle diagram of the PCB circuit board test system provided by the second embodiment of the utility model, N is greater than 1. When N is greater than 1, the common mode voltage elimination module 150 further includes a first line selection unit 170 and a second line selection unit 180, the first test voltage signal input port 120 is connected to the input end of the first line selection unit 170, the output end of the first line selection unit 170 is connected to the positive input end of the differential amplifier 160, the second test voltage signal access port 130 is connected to the input end of the second line selection unit 180, and the output end of the second line selection unit 180 is connected to the negative input end of the differential amplifier 160.

[0022] When N is greater than 1, the common-mode voltage cancellation module 150 adds a first line selection unit 170 and a second line selection unit 180. Their function is to dynamically adjust the input signal access path when there are multiple input signals. This allows the system to automatically select the appropriate signal path according to different situations, optimizing the common-mode voltage cancellation effect. The line selection unit is typically a switching circuit with multi-input selection functionality, capable of selecting a specific input signal based on different conditions; that is, the first line selection unit 170 and the second line selection unit 180 are multi-way switches. The first line selection unit 170 and the second line selection unit 180* are respectively connected to the first test voltage signal input port 120 and the second test voltage signal input port 130, and the corresponding signals are connected to the input terminals (positive input and negative input) of the differential amplifier through selection logic. With this design, the system can switch between different signal inputs or different signal paths as needed, ensuring that the signal is correctly processed by the differential amplifier and that common-mode voltage is eliminated. This design allows the system to adapt to more complex circuit environments, especially when multiple circuit boards are present, ensuring that each signal is properly processed and eliminating unnecessary common-mode voltage to the greatest extent possible.

[0023] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0024] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the above description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the following claims, the inventive aspect lies in fewer than all features of a single foregoing disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0025] Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0026] It should be noted that the above-mentioned examples illustrate rather than limit the application, and that those skilled in the art will be able to design many alternative examples without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word 'comprising' does not exclude the presence of elements or steps not listed in a claim. The word 'a' or 'an' preceding an element does not exclude the presence of a plurality of such elements. The application can be implemented by means of both hardware and software, and any combination thereof. In a unitary claim, several devices, apparatuses or means can be listed that can be implemented by one and the same item of hardware. These devices, apparatuses or means can also be implemented by means of one and the same item of hardware. The use of the terms first, second and third, etc. does not imply any ordering, but rather these terms are used as names.

Claims

1. A PCB test system capable of eliminating systematic noise interference, characterized in that, The application relates to a test circuit, which comprises a master PCB circuit board (100) and N slave PCB circuit boards (200), wherein N is a positive integer greater than or equal to 1, the master PCB circuit board (100) comprises a master power port (110), a first test voltage signal input port (120), a second test voltage signal access port (130), a master PCB circuit board ground terminal (140) and a common-mode voltage elimination module (150), each of the slave PCB circuit boards (200) comprises a slave power port (210), a test voltage signal output port (220) and a slave PCB circuit board ground terminal (230), the master power port (110) is connected with the slave power port (210) of each of the slave PCB circuit boards (200), the first test voltage signal input port (120) is connected with the test voltage signal output port (220) of each of the slave PCB circuit boards (200), the second test voltage signal access port (130) and the master PCB circuit board ground terminal (140) are connected with the slave PCB circuit board ground terminal (230) of each of the slave PCB circuit boards (200), and the common-mode voltage elimination module (150) is connected with the first test voltage signal input port (120) and the second test voltage signal access port (130).

2. The PCB test system of claim 1, wherein When N is equal to 1, the common-mode voltage elimination module (150) comprises a differential amplifier (160), the first test voltage signal input port (120) is connected with a positive input end of the differential amplifier (160), and the second test voltage signal access port (130) is connected with a negative input end of the differential amplifier (160).

3. The system of claim 2, wherein the system noise cancellation system further comprises: a system noise cancellation circuit configured to receive the system noise signal and the system noise cancellation signal and to generate a system noise cancellation signal; and a system noise cancellation amplifier configured to receive the system noise signal and the system noise cancellation signal and to generate the system noise cancellation signal. When N is greater than 1, the common-mode voltage elimination module (150) further comprises a first line selection unit (170) and a second line selection unit (180), the first test voltage signal input port (120) is connected with an input end of the first line selection unit (170), an output end of the first line selection unit (170) is connected with a positive input end of the differential amplifier (160), the second test voltage signal access port (130) is connected with an input end of the second line selection unit (180), and an output end of the second line selection unit (180) is connected with a negative input end of the differential amplifier (160).

4. The PCB circuit board testing system capable of eliminating system ground noise interference as described in claim 3, characterized in that, The first line selection unit (170) and the second line selection unit (180) are multiplexers.

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