A broadband voltage buffer

Abstract

The application discloses a broadband voltage buffer and belongs to the technical field of voltage measurement and signal conditioning. The application comprises a signal input module, an attenuation module, a buffer module, a filter module, a gain adjustment module and a signal output module; the signal input module is used for receiving a measured voltage signal, and the measured voltage signal is sequentially attenuated, buffered, filtered and gain-processed through the attenuation module, the buffer module, the filter module and the gain adjustment module, and then the processed measured voltage signal is output to an external device by the output module. The application constructs a modular voltage signal conditioning structure, so that the functional units work cooperatively, the anti-interference ability and environmental adaptability of the device are improved, and the protection ability of the back-end measuring equipment is enhanced.

Description

Technical Field

[0001] This invention relates to the field of voltage measurement and signal conditioning technology, and more specifically, to a wideband voltage buffer. Background Technology

[0002] With the continuous development of applications such as transient measurement, electromagnetic compatibility testing, high-voltage testing, and high-speed electronic testing in power systems, the demand for accurate measurement of wideband voltage signals is increasing. In actual measurement processes, the signals under test usually have characteristics such as wide bandwidth, fast rate of change, and obvious transient characteristics. Therefore, the front-end signal conditioning circuit needs to achieve stable transmission and effective isolation of the voltage signal while minimizing the impact on the operating state of the system under test.

[0003] In existing technologies, voltage buffer circuits often use operational amplifier follower structures or simple voltage divider networks to achieve signal conditioning, but these still have certain limitations in wideband application scenarios.

[0004] On the one hand, the input impedance of some buffer circuits is insufficient, which can easily create an additional load on the circuit under test, thereby changing the original electrical characteristics and affecting the measurement accuracy. On the other hand, traditional circuits have limited amplitude-frequency response performance and are prone to gain attenuation and phase distortion at high frequencies, making it difficult to guarantee high-fidelity signal transmission.

[0005] Furthermore, in environments with high common-mode voltage or strong electromagnetic interference, the lack of effective electrical isolation between the preceding and following stages can easily lead to interference coupling or even damage to downstream measurement equipment.

[0006] Meanwhile, the noise immunity and output drive capability of the existing device still have room for improvement, and output instability may occur under different load conditions. Summary of the Invention

[0007] To address the above problems, this invention proposes a wideband voltage buffer, comprising: a signal input module, an attenuation module, a buffer module, a filtering module, a gain adjustment module, and a signal output module; The signal input module is used to receive the measured voltage signal, and through the attenuation module, the buffer module, the filter module and the gain adjustment module, the measured voltage signal is attenuated, buffered, filtered and gain-processed in sequence, and then the output module outputs the processed measured voltage signal to an external device.

[0008] Optionally, the attenuation module includes: a resistor-capacitor (RC) compensation voltage divider structure, wherein the upper branch resistor and the lower branch resistor of the RC compensation voltage divider structure are respectively connected in parallel with compensation capacitors. By matching the time constant of each branch, the RC compensation voltage divider structure maintains a stable attenuation ratio over a wide frequency range to reduce amplitude error and phase distortion. At least one compensation capacitor Cc in the RC compensation voltage divider structure is an adjustable capacitor used to calibrate the frequency response to improve the accuracy of wideband signal measurement.

[0009] Optionally, the attenuation module also includes a multi-component voltage network, which allows for the selection of different attenuation ratios within the multi-component voltage network via a switching circuit to extend the dynamic measurement range.

[0010] Optionally, the buffer module adopts a multi-level buffer structure, including: a first-level high input impedance buffer circuit and a second-level high drive capability buffer circuit connected in sequence. The first-stage buffer circuit is used to perform primary isolation on the attenuated measured voltage signal and provide high input impedance to reduce the load effect on the front-end measured circuit. The second-stage buffer circuit is used to improve the output current driving capability and reduce the output impedance; The first-stage buffer circuit uses a voltage follower structure composed of a high-speed operational amplifier, and a damping resistor is set at the input terminal. The second-stage buffer circuit can be constructed using a high-bandwidth amplifier or a power-driven operational amplifier to drive low-impedance loads or long-distance transmission lines, while a matching resistor is set at the output.

[0011] Optionally, the filtering module is used to filter out high-frequency noise and out-of-band interference components in the measured voltage signal.

[0012] Optionally, the gain adjustment module can controllably adjust the amplification factor of the measured voltage signal to effectively compensate for the amplitude loss introduced by the attenuation module. The gain adjustment module adopts an adjustable amplifier circuit structure, and the gain can be matched and set according to the attenuation coefficient to make the total transmission coefficient approach 1.

[0013] Optionally, the output terminal of the output module can adopt a commonly used interface form.

[0014] Optionally, the signal input module, attenuation module, buffer module, filter module, gain adjustment module, and signal output module are connected in sequence.

[0015] Optionally, the wideband voltage buffer further includes an optocoupler isolation module, which is connected between the buffer module and the filter module for electrical isolation between the input signal channel and the output signal channel.

[0016] Optionally, the wideband voltage buffer may further include a power supply module for providing stable power to the wideband voltage buffer.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: This invention provides a wideband voltage buffer, comprising: a signal input module, an attenuation module, a buffer module, a filtering module, a gain adjustment module, and a signal output module. The signal input module receives the voltage signal to be measured, and through the attenuation module, the buffer module, the filtering module, and the gain adjustment module, the voltage signal is sequentially attenuated, buffered, filtered, and gain-processed, respectively. The output module then outputs the processed voltage signal to an external device. This invention constructs a modular voltage signal conditioning structure, enabling the functional units to work collaboratively to improve the device's anti-interference capability and environmental adaptability, and enhance the protection capability for downstream measurement equipment. This device is suitable for complex operating conditions such as high electromagnetic interference or high common-mode voltage, providing a reliable technical solution for the stable acquisition and safe transmission of wideband voltage signals. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the wideband voltage buffer of the present invention; Figure 2 This is a schematic diagram of the attenuation module of the wideband voltage buffer of the present invention; Figure 3 This is a schematic diagram of the buffer module of the wideband voltage buffer of the present invention. Detailed Implementation

[0019] Exemplary embodiments of the invention will now be described with reference to the accompanying drawings. However, the invention may be embodied in many different forms and is not limited to the embodiments described herein. These embodiments are provided to fully and completely disclose the invention and to fully convey its scope to those skilled in the art. The terminology used in the exemplary embodiments illustrated in the drawings is not intended to limit the invention. In the drawings, the same units / elements are referred to by the same reference numerals.

[0020] Unless otherwise stated, the terms used herein (including technical terms) have their common meaning as understood by one of ordinary skill in the art. Furthermore, it is understood that terms defined in commonly used dictionaries should be understood to have a meaning consistent with the context of their relevant field, and not to be interpreted as having an idealized or overly formal meaning.

[0021] Example 1: This invention proposes a wideband voltage buffer, such as... Figure 1As shown, it includes: a signal input module, an attenuation module, a buffer module, a filtering module, a gain adjustment module, and a signal output module; The signal input module is used to receive the measured voltage signal, and through the attenuation module, the buffer module, the filter module and the gain adjustment module, the measured voltage signal is attenuated, buffered, filtered and gain-processed in sequence, and then the output module outputs the processed measured voltage signal to an external device.

[0022] The attenuation module includes a resistor-capacitor (RC) compensation voltage divider structure. The upper and lower branch resistors of the RC compensation voltage divider structure are connected in parallel with compensation capacitors. By matching the time constants of each branch, the RC compensation voltage divider structure maintains a stable attenuation ratio over a wide frequency range to reduce amplitude error and phase distortion. At least one compensation capacitor Cc in the RC compensation voltage divider structure is an adjustable capacitor used to calibrate the frequency response to improve the accuracy of wideband signal measurement.

[0023] The attenuation module also includes a multi-component voltage network, which uses a switching circuit to select different attenuation ratios in the multi-component voltage network to extend the dynamic measurement range.

[0024] The buffer module adopts a multi-level buffer structure, including: a first-level high input impedance buffer circuit and a second-level high drive capability buffer circuit connected in sequence. The first-stage buffer circuit is used to perform primary isolation on the attenuated measured voltage signal and provide high input impedance to reduce the load effect on the front-end measured circuit. The second-stage buffer circuit is used to improve the output current driving capability and reduce the output impedance; The first-stage buffer circuit uses a voltage follower structure composed of a high-speed operational amplifier, and a damping resistor is set at the input terminal. The second-stage buffer circuit can be constructed using a high-bandwidth amplifier or a power-driven operational amplifier to drive low-impedance loads or long-distance transmission lines, while a matching resistor is set at the output.

[0025] The filtering module is used to filter out high-frequency noise and out-of-band interference components in the measured voltage signal.

[0026] Among them, the gain adjustment module can controllably adjust the amplification factor of the measured voltage signal, so that the amplitude loss introduced by the attenuation module can be effectively compensated. The gain adjustment module adopts an adjustable amplifier circuit structure, and the gain can be matched and set according to the attenuation coefficient to make the total transmission coefficient approach 1.

[0027] The output terminal of the output module can adopt a commonly used interface form.

[0028] The signal input module, attenuation module, buffer module, filtering module, gain adjustment module, and signal output module are connected in sequence.

[0029] The wideband voltage buffer also includes an optocoupler isolation module, which is connected between the buffer module and the filter module and is used for electrical isolation between the input signal channel and the output signal channel.

[0030] The wideband voltage buffer also includes a power supply module for providing stable power to the wideband voltage buffer.

[0031] The invention will be further illustrated below with specific examples: A wideband voltage buffer, such as Figure 1 As shown, the wideband voltage buffer includes a signal input unit, an attenuation module, a buffer module, an optocoupler isolation module, a filtering module, a gain adjustment module, a signal output unit, and a power supply module connected in sequence.

[0032] The signal input unit is used to receive the measured voltage signal, transmit the signal to the attenuation module, and set up an overvoltage protection circuit to improve the safety of the device.

[0033] The attenuation module adopts a resistor-capacitor compensated voltage divider structure, with the upper branch resistor and the lower branch resistor connected in parallel with compensation capacitors. This is achieved by matching the time constants of each branch (the resistance-capacitance relationship satisfies: ...). This ensures the circuit maintains a stable attenuation ratio over a wide frequency range, thereby reducing amplitude error and phase distortion. At least one compensation capacitor Cc in the attenuation circuit is adjustable and used to calibrate the frequency response, improving the accuracy of wideband signal measurements. Specifically, as shown... Figure 2 As shown. Furthermore, the attenuation module may include a multi-component voltage network, and different attenuation ratios may be selected through a switching circuit to extend the dynamic measurement range of the device.

[0034] The buffer module, such as Figure 3As shown, a multi-stage buffer structure is adopted, including a first-stage high-input-impedance buffer circuit and a second-stage high-drive-capability buffer circuit connected in sequence. The first-stage buffer circuit is used for primary isolation of the attenuated voltage signal, providing high input impedance to reduce the load effect on the front-end measured circuit. The second-stage buffer circuit is used to improve the output current drive capability and reduce the output impedance, thereby enhancing the device's adaptability to downstream measurement equipment or transmission lines. Specifically, the first-stage buffer circuit preferably adopts a voltage follower structure composed of a high-speed operational amplifier, with a damping resistor at the input to suppress high-frequency oscillations and improve the phase stability of the circuit, enabling stable transmission of wideband signals. The second-stage buffer circuit can be composed of a high-bandwidth amplifier or a power-driven operational amplifier to drive low-impedance loads or long-distance transmission lines, while a matching resistor is set at the output to reduce the impact of capacitive loads on system stability. Through the above multi-stage collaborative design, the front-end focuses on reducing measurement disturbances, while the rear-end focuses on enhancing drive capability, enabling the buffer module to balance high input impedance and low output impedance over a wide frequency range, thereby effectively reducing amplitude-frequency distortion and improving signal integrity.

[0035] The wideband voltage buffer also includes an optocoupler isolation module, located after the buffer module and before the filter module, for achieving electrical isolation between the input signal channel and the output signal channel. This optocoupler isolation module includes a light-emitting unit and a light-receiving unit. The light-emitting unit is connected to the output terminal of the buffer module, converting the electrical signal into an optical signal for transmission. The light-receiving unit receives the optical signal, converts it back to an electrical signal, and outputs it to the subsequent circuit, thereby cutting off the direct electrical connection between the preceding and following stages while allowing continuous signal transmission. Preferably, the bandwidth of the optocoupler isolation module is not less than the target operating bandwidth of the wideband voltage buffer.

[0036] The wideband voltage buffer also includes a filtering module, located after the optocoupler isolation module, for frequency shaping and noise suppression of the isolated signal. The filtering module removes high-frequency noise and out-of-band interference while maintaining amplitude stability and phase consistency of the signal within the target frequency band, thereby improving output signal quality and measurement accuracy. The cutoff frequency of the filtering module is higher than the upper limit of the target measurement frequency band, making signal attenuation within the target frequency band close to zero, while effectively suppressing out-of-band noise, thus avoiding measurement errors or system instability caused by high-frequency interference entering subsequent circuits.

[0037] The gain adjustment module is located after the filtering module and before the output terminal. It is used to perform amplitude compensation and fine adjustment on the voltage signal after pre-stage attenuation and buffering. The gain adjustment module works in conjunction with the attenuation module. By controllably adjusting the signal amplification factor, the amplitude loss introduced by the attenuation module is effectively compensated, thereby achieving proportional transmission between the overall input and output voltages of the buffer. The gain adjustment module adopts an adjustable amplifier circuit structure, and its gain can be matched and set according to the attenuation coefficient, making the overall transmission coefficient of the system approach 1, achieving a 1:1 voltage following output, and improving signal amplitude fidelity.

[0038] The output module is located after the gain adjustment module and is used to stably output the buffered, isolated, filtered, and gain-compensated voltage signal to external devices. The output terminal can adopt various commonly used interface types to enhance the device's versatility and engineering adaptability.

[0039] The wideband voltage buffer also includes a power supply module to provide stable power to each functional circuit, thereby reducing the impact of power fluctuations on wideband signal transmission.

[0040] This embodiment constructs a buffer device for broadband voltage measurement. The overall signal link sequentially includes a signal input unit, an attenuation module, a multi-level buffer module, an optocoupler isolation module, a filtering module, a gain adjustment module, a power supply module, and a signal output unit. Each module is installed in a metal shielded shell to reduce the influence of external electromagnetic interference on high-frequency signals.

[0041] (1) Signal input and protection: The signal input terminal uses a BNC coaxial interface with a characteristic impedance of 50Ω. A transient suppression diode (such as an SMBJ series TVS) and a gas discharge tube are connected in parallel at the input terminal to absorb transient overvoltages, thereby protecting the subsequent precision circuitry.

[0042] (2) Attenuation module: The attenuation module adopts a resistor-capacitor compensated voltage divider structure, wherein: The upper branch resistance is 900 kΩ. The lower branch resistance is 100 kΩ. This results in an attenuation ratio of approximately 10:1.

[0043] Compensating capacitors are connected in parallel to the upper and lower branches to ensure that the time constant matching relationship is met. R1C1 ≈ R2C2 The compensation capacitors are C0G / NP0 ceramic capacitors with stable high-frequency performance. At least one capacitor is a 2–10 pF adjustable capacitor, used to calibrate the high-frequency response during the commissioning phase, so that the amplitude-frequency error is preferably less than ±1dB within the target bandwidth.

[0044] Furthermore, by switching different voltage divider networks using relays, multiple attenuation levels of 1:1, 10:1, and 100:1 can be achieved to expand the input dynamic range.

[0045] (3) Multi-level buffer module: The buffer module includes a two-level structure: The first-stage buffer circuit uses a high-speed voltage feedback operational amplifier, such as the OPA656, AD8065, or other devices with a gain-bandwidth product of at least 300 MHz, to form a voltage follower. A damping resistor of approximately 20–100 Ω is connected in series at the input to suppress parasitic oscillations and improve phase margin.

[0046] The input impedance of this stage is preferably not less than 1 MΩ.

[0047] The second-stage buffer circuit employs a high-drive-capability amplifier, such as AD811, THS3091, or similar devices, to ensure that the output current capability is preferably no less than ±50 mA, thereby enabling the drive of low-impedance loads or long coaxial cables.

[0048] A matching resistor of approximately 49.9Ω is connected in series at the output terminal to reduce system instability caused by capacitive loads.

[0049] (4) Optical isolation module: The isolation module employs high-speed analog optocouplers, such as HCNR200 / HCNR201 or linear optocoupler structures, to achieve electrical isolation between the input and output. The isolation bandwidth is preferably no less than 1 MHz (or at least three times that based on the target bandwidth) to avoid becoming a system frequency bottleneck.

[0050] The isolation withstand voltage is preferably not less than 2.5 kVrms, thereby improving the safety of the device.

[0051] (5) Filtering module: The filtering module adopts a second-order active low-pass filter structure, and the cutoff frequency is preferably set to 5 MHz–20 MHz, which is higher than the upper limit of the target measurement bandwidth, so that the signal attenuation in the target frequency band is close to zero, while effectively suppressing out-of-band noise.

[0052] (6) Gain adjustment module: The gain adjustment module employs an adjustable feedback amplifier circuit, for example, by constructing a non-inverting amplifier structure using a precision resistor network. The feedback resistor can be a 0.1% precision thin-film resistor, calibrated using a fine-tuning potentiometer to ensure the overall system transfer coefficient meets the following requirements: 0.98 ≤ Vout / Vin ≤ 1.02 This achieves near unity gain transmission.

[0053] (7) Power supply and shielding structure: The power supply module uses a ±12V or ±15V bipolar linear power supply. The front stage is equipped with a switching power supply, and the rear stage uses a low-noise LDO (such as LT3045 type device) for secondary voltage regulation to reduce the impact of power supply ripple on wideband signals.

[0054] Each functional circuit adopts a partitioned layout, and a single-point grounding method is preferred to reduce ground loop noise.

[0055] The entire device is installed inside an aluminum alloy shielded housing, and key signal paths use coaxial or shielded wiring to reduce electromagnetic coupling interference.

[0056] (8) Output module: The output terminal uses a 50Ω BNC interface and provides low output impedance through a driver circuit, so that the device can maintain a stable voltage output when connected to devices such as oscilloscopes, data acquisition cards or spectrum analyzers.

[0057] In this embodiment, the broadband performance of the device of the present invention is tested: Ambient temperature: 20±2℃; Relative humidity: not higher than 70%; Test equipment: Function generator + 500 MHz bandwidth digital oscilloscope; Input signal range: 10Hz – 200kHz sine wave; The test results are as follows:

[0058] Test results show that: Gain error is less than ±0.01dB; Phase deviation less than 0.05°; It maintains stable output even under a 50Ω load condition; This verifies that the present invention has good amplitude and phase frequency characteristics over a wide frequency range.

[0059] Compared with the prior art, the present invention provides a wideband voltage buffer that, through the coordinated design of signal attenuation, buffer isolation, frequency shaping and gain compensation, enables the device to achieve high-fidelity and low-distortion voltage transmission over a wide frequency range. It has the advantages of high measurement accuracy, strong system stability and good engineering adaptability.

[0060] Specifically, the present invention has at least the following beneficial effects: (1) High broadband attenuation stability; By employing a voltage divider structure with RC compensation and matching the time constants of each branch, the attenuation ratio remains stable over a wide frequency range, effectively reducing amplitude error and phase distortion. At the same time, an adjustable compensation capacitor is set for frequency response calibration, thereby further improving the measurement accuracy of wideband signals.

[0061] (2) Balancing high input impedance and low output impedance; Employing a multi-stage buffer structure, the front stage provides high input impedance to reduce the load effect on the circuit under test, while the rear stage enhances current drive capability and reduces output impedance, enabling the device to maintain stable voltage transmission characteristics when connected to different loads, thereby improving signal integrity.

[0062] (3) Strong electrical isolation capability and high system security; By setting up an optocoupler isolation module, electrical isolation between input and output is achieved. While ensuring continuous signal transmission, direct electrical connection is cut off, effectively suppressing the impact of common-mode interference and abnormal voltage on downstream circuits, and improving the safety and anti-interference capability of the device operation.

[0063] (4) The output signal quality is better; After isolation, a filtering module is set up to suppress out-of-band noise and high-frequency interference, while maintaining the consistency of amplitude and phase within the target frequency band, thereby reducing measurement errors and enhancing system stability.

[0064] (5) Achieve near unity gain transmission overall; The gain adjustment module and the attenuation module work together to effectively compensate for the amplitude loss caused by attenuation, making the overall transmission coefficient of the buffer approach 1, realizing proportional transmission between input and output, and improving the signal amplitude fidelity.

[0065] This invention constructs a modular voltage signal conditioning structure, enabling the functional units to work collaboratively to improve the device's anti-interference capability and environmental adaptability, and enhance the protection capability for downstream measurement equipment. This device is suitable for complex operating conditions such as high electromagnetic interference or high common-mode voltage, providing a reliable technical solution for the stable acquisition and safe transmission of broadband voltage signals.

[0066] Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present invention can be implemented using various computer languages, such as the object-oriented programming language Java and the interpreted scripting language JavaScript.

[0067] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0068] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0069] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0070] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0071] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A wideband voltage buffer, characterized in that, include: The signal input module, attenuation module, buffer module, filtering module, gain adjustment module, and signal output module are all included. The signal input module is used to receive the measured voltage signal, and through the attenuation module, the buffer module, the filter module and the gain adjustment module, the measured voltage signal is attenuated, buffered, filtered and gain-processed in sequence, and then the output module outputs the processed measured voltage signal to an external device.

2. The wideband voltage buffer according to claim 1, characterized in that, The attenuation module includes: a resistor-capacitor compensation voltage divider structure, wherein the upper branch resistor and the lower branch resistor of the resistor-capacitor compensation voltage divider structure are respectively connected in parallel with compensation capacitors. By matching the time constant of each branch, the resistor-capacitor compensation voltage divider structure maintains a stable attenuation ratio over a wide frequency range to reduce amplitude error and phase distortion. At least one compensation capacitor Cc in the resistor-capacitor compensation voltage divider structure is an adjustable capacitor used to calibrate the frequency response to improve the accuracy of wideband signal measurement.

3. The wideband voltage buffer according to claim 2, characterized in that, The attenuation module also includes a multi-component voltage network, which uses a switching circuit to select different attenuation ratios in the multi-component voltage network to expand the dynamic measurement range.

4. The wideband voltage buffer according to claim 1, characterized in that, The buffer module adopts a multi-level buffer structure, including: a first-level high input impedance buffer circuit and a second-level high drive capability buffer circuit connected in sequence. The first-stage buffer circuit is used to perform primary isolation on the attenuated measured voltage signal and provide high input impedance to reduce the load effect on the front-end measured circuit. The second-stage buffer circuit is used to improve the output current driving capability and reduce the output impedance; The first-stage buffer circuit uses a voltage follower structure composed of a high-speed operational amplifier, and a damping resistor is set at the input terminal. The second-stage buffer circuit can be constructed using a high-bandwidth amplifier or a power-driven operational amplifier to drive low-impedance loads or long-distance transmission lines, while a matching resistor is set at the output.

5. The wideband voltage buffer according to claim 1, characterized in that, The filtering module is used to filter out high-frequency noise and out-of-band interference components in the measured voltage signal.

6. The wideband voltage buffer according to claim 1, characterized in that, The gain adjustment module controls the amplification factor of the measured voltage signal, thereby effectively compensating for the amplitude loss introduced by the attenuation module. The gain adjustment module adopts an adjustable amplifier circuit structure, and the gain can be matched and set according to the attenuation coefficient to make the total transmission coefficient approach 1.

7. The wideband voltage buffer according to claim 1, characterized in that, The output terminal of the output module can adopt a commonly used interface form.

8. The wideband voltage buffer according to claim 1, characterized in that, The signal input module, attenuation module, buffer module, filtering module, gain adjustment module, and signal output module are connected in sequence.

9. The wideband voltage buffer according to claim 8, characterized in that, Also includes: An optocoupler isolation module is connected between the buffer module and the filter module, and is used for electrical isolation between the input signal channel and the output signal channel.

10. The wideband voltage buffer according to claim 1, characterized in that, Also includes: The power supply module is used to provide stable power to the wideband voltage buffer.

Images