Multichannel multiplexing active probe

Abstract

The utility model provides a multichannel multiplexing active probe. The multichannel multiplexing active probe comprises a multichannel multiplexing active circuit, an MCU-based channel selection and control circuit and an output circuit, and the multichannel multiplexing active circuit is connected with the oscilloscope through the MCU-based channel selection and control circuit and the output circuit in sequence. The utility model has the beneficial effects that: 1, the multi-channel probe can process signals of a plurality of channels at the same time, thereby greatly improving the signal processing efficiency and solving the problem of low efficiency of a single-channel probe; and 2, the oscilloscope channel can be multiplexed with extremely low distortion degree, so that the signal processing precision is ensured. And 3, a multiplexing channel can be selected through the upper computer, so that the operation steps are greatly simplified, the operation difficulty is reduced, and the working efficiency is improved. And 4, the signal acquisition function of different test items can be realized, the flexibility of the system is enhanced, and the system can adapt to more application scenes.

Description

Technical Field

[0001] The utility model relates to the technical fields of signal processing, probe design and multi-channel multiplexing technology. Specifically, it relates to a multi-channel multiplexing active probe. Background Art

[0002] In the technical fields of signal processing, probe design and multi-channel multiplexing technology, the acquisition and processing of signals are an important link. The design and performance of the probe directly affect the accuracy and efficiency of signal processing, while multi-channel multiplexing technology can improve the efficiency and flexibility of signal processing. In many data acquisition tasks that require capturing DC or AC signals at different circuit nodes, the design and performance of the probe are particularly important.

[0003] The existing solutions mainly use single-channel probes for signal acquisition and processing, and the problems thereof mainly include the following points:

[0004] Firstly, the efficiency of single-channel probes is low and cannot meet the requirements of modern signal processing.

[0005] Secondly, when processing AC detection signals, single-channel probes have high requirements for signal probe leads and are prone to detection distortion phenomena such as signal edge degradation and overshoot. These problems not only affect the accuracy of signal processing but also reduce the work efficiency.

[0006] Finally, the existing single-channel probes are complex to operate and require a large amount of manual settings and adjustments, which not only reduces the work efficiency but also increases the operation difficulty. Summary of the Utility Model

[0007] The utility model aims to provide a multi-channel multiplexing active probe to solve the problems existing in using single-channel probes for signal acquisition and processing.

[0008] A multi-channel multiplexing active probe provided by the utility model includes:

[0009] A multi-channel multiplexing active circuit, a channel selection and control circuit based on MCU, and an output circuit;

[0010] The multi-channel multiplexing active circuit is connected to an oscilloscope through a channel selection and control circuit based on MCU and an output circuit in sequence.

[0011] In one embodiment, each channel in the multi-channel multiplexing active circuit includes a voltage division circuit and a high-bandwidth buffer BUF1; the voltage division circuit is connected to a corresponding input terminal on the channel selection and control circuit based on MCU through the high-bandwidth buffer BUF1.

[0012] In one embodiment, the voltage dividing circuit includes a first voltage dividing network and a second voltage dividing network; on the one hand, the first voltage dividing network is connected to the high-bandwidth buffer BUF1, and on the other hand, it is grounded through the second voltage dividing network.

[0013] In one embodiment, the first voltage dividing network includes a resistor R1 and a capacitor C1 connected in parallel; the second voltage dividing network includes a resistor R2 and a capacitor C2 connected in parallel.

[0014] In one embodiment, the first voltage dividing network further includes a variable resistor R1'; after the resistor R1 and the variable resistor R1' are connected in series, they are then connected in parallel with the capacitor C1; the second voltage dividing network further includes a variable resistor R2'; after the resistor R2 and the variable resistor R2' are connected in series, they are then connected in parallel with the capacitor C2.

[0015] Preferably, the capacitors C1 and C2 are adjustable capacitors.

[0016] In one embodiment, the MCU-based channel selection and control circuit includes a multiplexing switch MUX and a microprocessor MCU; the control terminal of the multiplexing switch MUX is connected to the host computer through the microprocessor MCU.

[0017] The N input terminals of the multiplexing switch MUX are correspondingly connected to the N channel output terminals in the multi-channel multiplexing active circuit; the output terminal of the multiplexing switch MUX is connected to the oscilloscope through the output circuit.

[0018] In one embodiment, N can take values of 4, 8, 16, 24, 32 or 48.

[0019] Further, the output circuit includes a high-bandwidth buffer BUF2, a resistor R3 and a coaxial cable Cable1; the high-bandwidth buffer BUF2 is connected to the oscilloscope through the resistor R3 and the coaxial cable Cable1 in sequence.

[0020] Preferably, the resistance value of the resistor R3 is equal to the input impedance R5 of the oscilloscope.

[0021] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present utility model are as follows:

[0022] 1. High efficiency: The multi-channel multiplexing active probe provided by the present utility model can process signals of multiple channels simultaneously, greatly improving the signal processing efficiency and solving the problem of low efficiency of single-channel probes. This has great advantages for data acquisition work that needs to capture DC or AC signals at different circuit nodes.

[0023] 2. High precision: The multi-channel multiplexing active probe of the present utility model can multiplex oscilloscope channels with extremely low distortion, thus ensuring the accuracy of signal processing. This has important practical value for occasions where probe leads that require precise signal capture are needed to avoid detection distortion phenomena such as signal edge degradation and overshoot.

[0024] 3. Easy to operate: The multi-channel multiplexing active probe of the present utility model can select multiplexing channels through a host computer, greatly simplifying the operation steps, reducing the operation difficulty, and improving the work efficiency. This has important practical value for occasions that require a large number of settings and adjustments.

[0025] 4. Strong flexibility: The multi-channel multiplexing active probe of the present utility model can realize the signal acquisition function for different test items, enhancing the flexibility of the system and enabling the system to adapt to more application scenarios. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the accompanying drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present utility model, and thus should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is the schematic diagram of the multi-channel multiplexing active probe in the embodiment of the present utility model.

[0028] Figure 2 It is the schematic diagram of the first implementation method of the multi-channel multiplexing active circuit in the embodiment of the present utility model.

[0029] Figure 3 It is the schematic diagram of the second implementation method of the multi-channel multiplexing active circuit in the embodiment of the present utility model.

[0030] Figure 4 It is the schematic diagram of the third implementation method of the multi-channel multiplexing active circuit in the embodiment of the present utility model.

[0031] Figure 5 It is the schematic diagram of the channel selection and control circuit based on MCU in the embodiment of the present utility model.

[0032] Figure 6 It is the schematic diagram of the output circuit in the embodiment of the present utility model. Detailed Implementation Manner

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Generally, the components of the embodiments of the present utility model described and illustrated herein can be arranged and designed in various different configurations.

[0034] Therefore, the following detailed description of the embodiments of the present utility model provided in the drawings is not intended to limit the scope of the claimed present utility model, but merely represents selected embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts fall within the scope of protection of the present utility model.

[0035] Embodiment

[0036] As Figure 1 shown, this embodiment provides a multi-channel multiplexing active probe, which includes:

[0037] A multi-channel multiplexing active circuit, a channel selection and control circuit based on an MCU, and an output circuit;

[0038] The multi-channel multiplexing active circuit is connected to an oscilloscope through a channel selection and control circuit based on an MCU and an output circuit in sequence.

[0039] (1) Multi-channel multiplexing active circuit

[0040] In this embodiment, the designed multi-channel multiplexing active circuit has N (such as N = 4, 8, 16, 24, 32, 48, etc.) channels, the bandwidth of each channel is 100 MHz, and the input impedance is 10 MΩ. It should be noted that these parameters can all be designed according to actual needs. As Figure 2 、 Figure 3 、 Figure 4 shown, each channel in the multi-channel multiplexing active circuit includes a voltage division circuit and a high-bandwidth buffer BUF1; the voltage division circuit is connected to a corresponding input terminal on the channel selection and control circuit based on an MCU through the high-bandwidth buffer BUF1.

[0041] More specifically, the voltage division circuit includes a first voltage division network and a second voltage division network; on the one hand, the first voltage division network is connected to the high-bandwidth buffer BUF1, and on the other hand, it is grounded through the second voltage division network.

[0042] The implementation manner of the multi-channel multiplexing active circuit is as Figure 2 shown:

[0043] The first voltage dividing network includes a resistor R1 and a capacitor C1 connected in parallel; the second voltage dividing network includes a resistor R2 and a capacitor C2 connected in parallel. The resistance ratio of resistor R1 and resistor R2 can be designed as 9:1. For example, resistor R1 = 9 MΩ, resistor R2 = 1 MΩ. Resistor R1 and resistor R2 form a 10:1 DC voltage dividing network with an input impedance of 10 MΩ to divide the DC signal to be collected. Capacitor C1 and capacitor C2 form an AC voltage dividing network, and then output to the subsequent circuit through a high-bandwidth buffer BUF1.

[0044] The second implementation method of the multi-channel multiplexing active circuit is as Figure 3 shown:

[0045] On the basis of Figure 2 , the first voltage dividing network further includes a variable resistor R1'; after resistor R1 and variable resistor R1' are connected in series, they are then connected in parallel with capacitor C1; the second voltage dividing network further includes a variable resistor R2'; after resistor R2 and variable resistor R2' are connected in series, they are then connected in parallel with capacitor C2. Variable resistor R1' and variable resistor R2' are used to finely adjust the voltage division ratio to accurately adjust the voltage division ratio of the resistor network.

[0046] The third implementation method of the multi-channel multiplexing active circuit is as Figure 4 shown:

[0047] On the basis of Figure 3 , capacitor C1 and capacitor C2 are adjustable capacitors. The parasitic capacitance parameters of the circuit can be measured through experiments to adjust the values of adjustable capacitor C1 and adjustable capacitor C2, so that the phase of the input AC signal CHx-IN remains unchanged after passing through this voltage dividing network.

[0048] (2) MCU-based channel selection and control circuit

[0049] As Figure 5 shown, the MCU-based channel selection and control circuit includes a multiplexing selection switch MUX and a microprocessor MCU; the control terminal of the multiplexing selection switch MUX is connected to the host computer through the microprocessor MCU; the N input terminals of the multiplexing selection switch MUX are correspondingly connected to the N channel output terminals in the multi-channel multiplexing active circuit; the output terminal of the multiplexing selection switch MUX is connected to the oscilloscope through an output circuit.

[0050] The host computer outputs a control signal to the microprocessor MCU, and the microprocessor MCU controls the selection of the corresponding channel (one or more channels) for signal acquisition according to the received control signal. Thus, through the control of the host computer, the signal acquisition of different test items can be realized.

[0051] (3) Output circuit

[0052] As Figure 6As shown, the output circuit includes a high-bandwidth buffer BUF2, a resistor R3, and a coaxial cable Cable1; the high-bandwidth buffer BUF2 is connected to an oscilloscope through the resistor R3 and the coaxial cable Cable1 in sequence.

[0053] That is, the multi-channel multiplexed array output signal output by the multiplexing selection switch MUX is input to the oscilloscope through the coaxial cable Cable1 after passing through the high-bandwidth buffer BUF2. Among them, the resistance value of the resistor R3 is equal to the input impedance R5 of the oscilloscope, achieving impedance matching for signal transmission.

[0054] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A multi-channel multiplexed active probe, characterized in that: include: Multi-channel multiplexing active circuit, MCU-based channel selection and control circuit and output circuit; The multi-channel multiplexing active circuit is connected to the oscilloscope in sequence via the channel selection and control circuit based on the MCU and the output circuit.

2. The multi-channel multiplexed active probe according to claim 1, characterized in that: Each channel in the multi-channel multiplexing active circuit includes a voltage divider circuit and a high-bandwidth buffer BUF1; the voltage divider circuit is connected to a corresponding input terminal of a channel selection and control circuit based on an MCU via the high-bandwidth buffer BUF1.

3. The multi-channel multiplexed active probe according to claim 2, characterized in that: The voltage divider circuit includes a first voltage divider network and a second voltage divider network; the first voltage divider network is connected to the high-bandwidth buffer BUF1 on one hand, and is grounded via the second voltage divider network on the other hand.

4. The multi-channel multiplexed active probe according to claim 3, characterized in that: The first voltage-dividing network includes a resistor R1 and a capacitor C1 connected in parallel; the second voltage-dividing network includes a resistor R2 and a capacitor C2 connected in parallel.

5. The multi-channel multiplexed active probe according to claim 4, characterized in that: The first voltage-dividing network further includes an adjustable resistor R1'; the resistor R1 and the adjustable resistor R1' are connected in series and then connected in parallel with the capacitor C1; the second voltage-dividing network further includes an adjustable resistor R2'; the resistor R2 and the adjustable resistor R2' are connected in series and then connected in parallel with the capacitor C2.

6. The multi-channel multiplexed active probe according to claim 4 or 5, characterized in that: The capacitor C1 and the capacitor C2 are adjustable capacitors.

7. The multi-channel multiplexed active probe according to claim 1, characterized in that: The MCU-based channel selection and control circuit includes a multiplexing selection switch MUX and a microprocessor MCU; the control end of the multiplexing selection switch MUX is connected to a host computer via the microprocessor MCU; The N input terminals of the multiplexing selection switch MUX are correspondingly connected to the N channel output terminals in the multi-channel multiplexing active circuit; The output end of the multiplexing selection switch MUX is connected to the oscilloscope via the output circuit.

8. The multi-channel multiplexed active probe according to claim 7, characterized in that: The value of N is 4, 8, 16, 24, 32 or 48.

9. The multi-channel multiplexed active probe according to claim 1, characterized in that: The output circuit includes a high-bandwidth buffer BUF2, a resistor R3 and a coaxial cable Cable1; the high-bandwidth buffer BUF2 is connected to an oscilloscope via the resistor R3 and the coaxial cable Cable1 in sequence.

10. The multi-channel multiplexed active probe according to claim 9, characterized in that: The resistance value of resistor R3 is equal to the input impedance R5 of the oscilloscope.

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