High-precision resistor resistance value detection circuit

Abstract

The invention is suitable for the technical field of circuit detection, provides a high-precision resistance value detection circuit, and aims to realize high-precision measurement of resistance value of a resistor through an accurate current source, stable reference voltage, efficient analog-to-digital conversion and stable power management. The circuit comprises a current source module, an input voltage buffer module, a conversion circuit module, a reference voltage circuit module, an MCU module and a clock circuit module. The current source provides constant current, the input voltage buffer module reduces noise, the conversion circuit module converts voltage into digital signals, the reference voltage circuit module provides stable reference voltage, the MCU module calculates resistance, and the clock circuit module synchronously samples and converts. The circuit overcomes the problem that the cost and the precision are difficult to consider at the same time, improves the accuracy and the stability of measurement, and is suitable for occasions needing high-precision resistance measurement.

Description

Technical Field

[0001] The invention belongs to the technical field of circuit detection, and in particular relates to a high-precision resistor value detection circuit. Background Art

[0002] Traditional resistance measurement includes the use of voltammetry, Wheatstone bridge and other methods. For example, voltammetry is simple but has limited accuracy, while Wheatstone bridge has high accuracy but requires precise components and balance adjustment, and the measurement cost is high. In addition, power supply fluctuations and environmental changes may affect the stability of resistance measurement. In scenarios where a large number of resistors need to be measured quickly, traditional methods may not respond quickly enough, but high-precision measurement equipment is often expensive.

[0003] Therefore, the prior art has defects. Summary of the invention

[0004] The purpose of the present invention is to overcome the above-mentioned shortcomings of the prior art that cost and accuracy cannot be taken into account at the same time, and to provide a high-precision resistor value detection circuit.

[0005] The present invention is implemented as follows: a high-precision resistance value detection circuit, comprising:

[0006] A current source module, used for providing a constant current to the resistor to be measured;

[0007] An input voltage buffer module, which buffers the input voltage of the current source module and is connected to the resistor to be measured;

[0008] A conversion circuit module, used for converting the voltage across the resistor to be tested into a digital signal;

[0009] The reference voltage circuit module includes a buffer module to generate and stabilize the reference voltage, which is directly supplied to the reference voltage input terminal of the conversion circuit module;

[0010] MCU module, the conversion circuit module is connected to the MCU module through an SPI interface, the MCU module receives the digital signal from the conversion circuit module, calculates and outputs the resistance value of the resistor to be measured;

[0011] The clock circuit module is connected to the conversion circuit module and is used to generate a stable clock signal to synchronize the sampling and conversion process of the conversion circuit module.

[0012] Furthermore, it also includes an analog circuit voltage supply module to provide a stable voltage for the current source module, the input voltage buffer module and the conversion circuit module.

[0013] Furthermore, it also includes a digital circuit voltage supply module to provide a stable voltage for the conversion circuit module and the clock circuit module.

[0014] Furthermore, the current source module, the resistor to be measured, the input voltage buffer module, the conversion circuit module and the MCU module are connected in series in sequence.

[0015] Furthermore, the conversion circuit module includes an ADR3425 chip, one end of the ADR3425 chip is connected to the reference voltage circuit, the reference voltage circuit provides a stable reference voltage module for the ADR3425 chip to perform the conversion function, and the other end is connected to communicate with the MCU module through the SPI interface.

[0016] Furthermore, the circuit also includes a power management module, which includes a U6 RS3236-3.3Yf3 chip arranged in the analog circuit voltage supply module and a U4 RS3236-3.3Yf3 chip arranged in the digital circuit voltage supply module, both of which are used to provide a stable voltage.

[0017] Furthermore, the reference voltage circuit module provides a stable 2.5V power supply.

[0018] Furthermore, the power management module is used to provide a stable 3.3V power supply.

[0019] A high-precision resistor value detection circuit provided by the present invention improves measurement accuracy through a stable reference voltage circuit module and a constant current source module, so that high-precision measurement can be achieved without increasing excessive costs; voltage fluctuations and noise are reduced through an input voltage buffer module, the integrity of signals during transmission is ensured, signal loss and interference are reduced, system errors are reduced, the accuracy of measurement results is improved, the additional costs caused by signal problems are reduced, and the measurement quality is improved within a cost-controllable range; the stable reference voltage circuit module and the clock circuit module reduce the impact of environmental changes on measurement results, enhance the stability of the entire measurement system, and maintain measurement accuracy at a relatively low cost; the entire measurement circuit achieves the goal of obtaining high-precision measurement results at a relatively low cost by improving measurement accuracy and system stability while reducing power consumption and maintenance costs, and effectively overcomes the deficiencies in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] The following drawings are only intended to illustrate and explain the present invention, and are not intended to limit the scope of the present invention.

[0022] Figure 1 The invention provides a circuit block diagram of a high-precision resistor value detection circuit.

[0023] Figure 2 The invention discloses a circuit diagram of a high-precision resistor value detection circuit.

[0024] Description of the drawings: 1. Current source module; 2. Input voltage buffer module; 3. Conversion circuit module; 4. Reference voltage circuit module; 41. Buffer module; 5. MCU module; 6. Clock circuit module; 7. Analog circuit voltage supply module; 8. Digital circuit voltage supply module. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0026] See also Figure 1-Figure 2 , is a high-precision resistance value detection circuit disclosed in the invention, which can accurately detect the resistance value of the resistance to be measured. The detection circuit specifically includes a current source module 1, an input voltage buffer module 412, a conversion circuit module 3, a reference voltage circuit module 4, an MCU module 5 and a clock circuit module 6. Among them: the resistance to be measured, the input voltage buffer module, the conversion circuit module 3 and the MCU module 5 are connected in series in sequence, and the reference voltage circuit module 4 and the clock circuit module 6 are connected to the conversion circuit module 3 at the same time.

[0027] The current source module 1 is directly connected to both ends of the resistor to be measured to ensure that the current flows stably, and is used to provide a constant current to the resistor to be measured. The constant current reduces the current fluctuation during the measurement process and improves the accuracy of the measurement.

[0028] The input voltage buffer module 412 buffers the input voltage of the current source module 1 and connects it to the resistor to be measured, thereby buffering the voltage sampled from the resistor to be measured, reducing voltage fluctuation and noise, and improving signal stability. The input voltage buffer module 412 is located after the resistor to be measured, and the voltage across the resistor to be measured is processed by the input voltage buffer module 412 and then transmitted to the conversion circuit module 3. The input voltage buffer module 412 reduces the influence of voltage noise on the measurement result and improves the measurement accuracy.

[0029] The conversion circuit module 3 is used to convert the voltage across the resistor to be measured into a digital signal, and the reference voltage circuit module 4 includes a buffer module 41 to generate and stabilize the reference voltage, which is directly supplied to the reference voltage input terminal of the conversion circuit module 3. The reference voltage circuit module 4 specifically provides a stable 2.5V power supply, which is a standard voltage for many circuits to ensure compatibility. Specifically, the conversion circuit module 3 includes an ADR3425 chip, and the task of performing the function of converting analog signals to digital signals is mainly completed by the ADR3425 chip. One end of the ADR3425 chip is connected to the reference voltage circuit, and the reference voltage circuit provides a stable reference voltage module for the ADR3425 chip to perform the conversion function, and the other end is connected to communicate with the MCU module 5 through the SPI interface.

[0030] The MCU module 5 and the conversion circuit module 3 are connected to the MCU module 5 via an SPI interface. The MCU module 5 receives the digital signal from the conversion circuit module 3, processes the digital signal, calculates and outputs the resistance value of the resistor to be measured. The precise calculation capability of the MCU module 5 ensures the accurate conversion from the digital signal to the resistance value.

[0031] The detection circuit also mainly includes a clock circuit module 6, which is connected to the conversion circuit module 3 and is used to generate a stable clock signal to synchronize the sampling and conversion process of the conversion circuit module 3 to ensure the synchronization of sampling and conversion. The stable clock signal reduces clock jitter and improves the accuracy of sampling and conversion.

[0032] Furthermore, an analog circuit voltage supply module 7 is included, wherein the analog circuit processes continuously changing signals, which may be in the form of voltage, current or frequency, etc. In this detection circuit, the current source module 1, the input voltage buffer module 412 and the conversion circuit module 3 are all classified as the analog circuit. The analog circuit voltage supply module 7 specifically provides a stable voltage for the analog circuit, that is, the analog circuit voltage supply module 7 provides a stable voltage for the current source module 1, the input voltage buffer module 412 and the conversion circuit module 3. The stable voltage supply reduces the influence of power supply fluctuations on the measurement results.

[0033] Furthermore, a digital circuit voltage supply module 8 is included, wherein the digital circuit processes discrete binary signals, which have only two states, usually represented as 0 and 1, and represent digital information. In this detection circuit, the conversion circuit module 3 and the clock circuit module 6 are both classified as digital circuits. The digital circuit voltage supply module 8 specifically provides a stable voltage for the digital circuit, that is, the digital circuit voltage supply module 8 provides a stable voltage for the conversion circuit module 3 and the clock circuit module 6. A stable voltage supply is essential for the stable operation of the digital circuit.

[0034] In the above-mentioned analog circuit and digital circuit, the conversion circuit module 3 is included. Since the conversion circuit module 3 itself is a mixed signal device, it processes analog signals and digital signals at the same time. The conversion circuit module 3 needs to obtain signals from the analog circuit, which are usually the voltage on the resistor to be measured. The analog circuit voltage supply module 7 provides a stable power supply for the relevant analog signal path to ensure the integrity and accuracy of the signal. After the conversion circuit module 3 converts the analog signal into a digital signal, it is necessary to send these digital signals to the digital circuit for further processing and analysis. The digital circuit voltage supply module 8 provides a stable power supply for the digital part of the conversion circuit module 3 and the MCU module 5 communicating with it. By providing independent power supplies for the analog and digital parts of the conversion circuit module 3, the mutual interference between the two parts can be reduced and the signal integrity of the entire circuit can be improved. A stable power supply is essential to the performance of the conversion circuit module 3, especially in high-precision measurement applications. Ensuring that both the analog and digital parts of the conversion circuit module 3 have appropriate power supplies helps to improve the accuracy and reliability of the measurement.

[0035] Furthermore, the circuit also includes a power management module, which includes a U6 RS3236-3.3Yf3 chip provided in the analog circuit voltage supply module 7 and a U4 RS3236-3.3Yf3 chip provided in the digital circuit voltage supply module 8, both of which are used to provide a stable voltage. The power management module is used to specifically provide a stable 3.3V power supply. The 3.3V voltage level is relatively low, which helps to reduce the power consumption of the integrated circuit, and the low voltage operation reduces the energy consumption during switching. In high-speed digital circuits, the 3.3V power supply helps to maintain good signal integrity, reduce noise and interference, ensure the power supply stability of each part of the circuit, and reduce the influence of power supply fluctuations on the measurement results.

[0036] The current source module 1 and the power management module ensure a constant current and a stable voltage supply, reducing the impact of power supply fluctuations on the measurement results. The reference voltage circuit module 4 provides an accurate reference voltage for the conversion circuit module 3, ensuring the accuracy of the conversion. The conversion circuit module 3 accurately converts the analog signal into a digital signal, reducing the error in the conversion process. The clock circuit module 6 provides a stable clock signal for the conversion circuit module 3, reducing clock jitter and improving the accuracy of sampling and conversion. The MCU module 5 accurately calculates the conversion from digital signals to resistance values, ensuring the accuracy of the final result. Through the collaborative work of the above modules, this circuit achieves high-precision measurement of the resistance value, overcoming the shortcomings of the prior art that cost and accuracy cannot be taken into account.

[0037] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-precision resistance value detection circuit, characterized in that: include: A current source module (1), used for providing a constant current to the resistor to be measured; An input voltage buffer module (41) (2) buffers the input voltage of the current source module (1) and connects it to the resistor to be measured; A conversion circuit module (3), used for converting the voltage across the resistor to be measured into a digital signal; The reference voltage circuit module (4) comprises a buffer module (41) for generating and stabilizing the reference voltage, which is directly supplied to the reference voltage input terminal of the conversion circuit module (3); An MCU module (5), wherein the conversion circuit module (3) is connected to the MCU module (5) via an SPI interface, and the MCU module (5) receives a digital signal from the conversion circuit module (3), calculates and outputs the resistance value of the resistor to be measured; The clock circuit module (6) is connected to the conversion circuit module (3) and is used to generate a stable clock signal to synchronize the sampling and conversion process of the conversion circuit module (3).

2. A high-precision resistance value detection circuit according to claim 1, characterized in that: It also includes an analog circuit voltage supply module (7) for providing a stable voltage to the current source module (1), the input voltage buffer module (41) (2) and the conversion circuit module (3).

3. A high-precision resistance value detection circuit according to claim 2, characterized in that: It also includes a digital circuit voltage supply module (8) for providing a stable voltage to the conversion circuit module (3) and the clock circuit module (6).

4. The high-precision resistance value detection circuit according to claim 1, characterized in that: The current source module (1), the resistor to be measured, the input voltage buffer module, the conversion circuit module (3) and the MCU module (5) are sequentially connected in series.

5. The high-precision resistance value detection circuit according to claim 1, characterized in that: The conversion circuit module (3) comprises an ADR3425 chip, one end of the ADR3425 chip is connected to the reference voltage circuit, the reference voltage circuit provides a stable reference voltage module for the ADR3425 chip to perform the conversion function, and the other end is connected to communicate with the MCU module (5) via an SPI interface.

6. The high-precision resistance value detection circuit according to claim 3, characterized in that: The circuit also includes a power management module, which includes a U6 RS3236-3.3Yf3 chip arranged in the analog circuit voltage supply module (7) and a U4 RS3236-3.3Yf3 chip arranged in the digital circuit voltage supply module (8), both of which are used to provide a stable voltage.

7. The high-precision resistance value detection circuit according to claim 1, characterized in that: The reference voltage circuit module (4) provides a stable 2.5V power supply.

8. The high-precision resistance value detection circuit according to claim 6, characterized in that: The power management module is used to provide a stable 3.3V power supply.

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