Resistance value detection circuit
By combining the comparison module, latching module, and analog-to-digital conversion module of the resistance value detection circuit, the problems of insufficient real-time performance and accuracy in the existing resistance value detection technology are solved, realizing fast and accurate resistance value detection, which is suitable for applications with high real-time requirements.
Patent Information
- Application Number
- CN202511146644.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-15
- Publication Date
- 2025-10-28
AI Technical Summary
Existing technologies suffer from insufficient data accuracy and low real-time performance when rapidly testing or detecting resistance values in real time. In particular, data loss is severe during dynamic testing, making them unsuitable for applications requiring high real-time performance.
By employing a combination of a comparison module, a latching module, a processing module, and an analog-to-digital conversion module, the system compares the voltage to be measured with a reference voltage, latches abnormal signals, and triggers the analog-to-digital conversion module to read the resistance value. This reduces the operational burden on the analog-to-digital conversion module and improves detection speed and accuracy.
It enables rapid and accurate resistance detection in real-time applications, reduces the performance requirements of the analog-to-digital conversion module, reduces data processing in the processing module, and improves detection efficiency and accuracy.
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Figure CN120847481A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of integrated circuit technology, and in particular to a resistance value detection circuit. Background Technology
[0002] In related technologies, many DCR (Direct Current Resistance) tests power the product under test (DUT) with a constant current or constant voltage source, then use an ADC to read the sampled current and voltage values to calculate the DCR value. However, for applications requiring rapid testing or real-time detection, such as swing aging tests or tensile tests where the product's impedance or contact impedance needs to be measured during movement, this dynamic testing method typically uses a fast ADC (Analog-to-Digital Converter) to acquire signals. However, the long data reading time of a fast ADC results in a large data volume, which may lead to data loss and insufficient data accuracy. Large amounts of data also increase the MCU's processing time, making it unsuitable for applications with high real-time requirements.
[0003] In summary, the technical problems existing in the relevant technologies need to be improved. Summary of the Invention
[0004] The main objective of this application is to provide a resistance value detection circuit that can improve the detection speed and accuracy of resistance values.
[0005] To achieve the above objectives, one aspect of this application provides a resistance value detection circuit, which includes a comparison module, a latching module, a processing module, and an analog-to-digital conversion module. The comparison module is used to obtain the voltage to be measured of the resistor under test, compare the voltage to be measured with a preset reference voltage, and output the comparison result. The latch module is connected to the comparison module and is used to output an abnormal signal when the comparison result indicates an abnormal state. The processing module is connected to the latch module and is used to send a read signal to the analog-to-digital conversion module in response to the abnormal signal; The analog-to-digital conversion module is connected to the processing module and is used to send the voltage digital signal and current digital signal of the resistor under test to the processing module in response to the read signal. The processing module is also used to calculate the resistance value of the resistor under test based on the voltage digital signal and the current digital signal.
[0006] In some embodiments, the resistance detection circuit further includes a constant current electronic load module and a power supply module, wherein the power supply module is connected to the first terminal of the resistor under test, and the constant current electronic load module is connected to the second terminal of the resistor under test. The power module is used to provide an initial voltage to the resistor under test; The constant current electronic load module is used to control the current passing through the resistor under test to be a constant current.
[0007] In some embodiments, the resistance detection circuit further includes an operational amplifier, which is disposed between the comparison module and the resistor to be measured; The operational amplifier is used to acquire the initial voltage across the resistor under test; the initial voltage is amplified to obtain the voltage under test.
[0008] In some embodiments, the comparison module includes a first comparator and a second comparator, and the output terminal of the operational amplifier is connected to the positive input terminal of the first comparator and the negative input terminal of the second comparator, respectively. The negative input terminal of the first comparator is used to obtain the lower limit reference voltage; The positive input terminal of the second comparator is used to obtain the upper limit reference voltage; The first comparator is used to compare the voltage to be measured with the lower limit reference voltage; if the voltage to be measured is less than the lower limit reference voltage, a first comparison result indicating an anomaly is output. The second comparator is used to compare the voltage to be measured with the upper limit reference voltage; if the voltage to be measured is greater than the upper limit reference voltage, a second comparison result indicating an anomaly is output. The reference voltage includes the lower limit reference voltage and the upper limit reference voltage, and the comparison result includes the first comparison result and the second comparison result.
[0009] In some embodiments, the resistance detection circuit further includes a debouncing filter module, the input of which is connected to the output of the comparison module, and the output of which is connected to the input of the latch module. The debouncing filter module is used to filter out interference signals in the comparison result and send the comparison result after filtering out interference signals to the latch module.
[0010] In some embodiments, the latch module includes a first latch and a second latch, wherein the first latch is connected to the first comparator and the second latch is connected to the second comparator; The first latch is used to output a first exception signal in response to the first comparison result; The first latch is used to output a second exception signal in response to the second comparison result; The abnormal signals include a first abnormal signal and a second abnormal signal.
[0011] In some embodiments, the analog-to-digital conversion module includes a current acquisition unit, a voltage acquisition unit, and an analog-to-digital converter. The current acquisition unit is connected to the constant current electronic load module, and the voltage acquisition unit is connected to the operational amplifier. The current acquisition unit is used to acquire the differential current signal output by the constant current electronic load module and amplify the differential current signal to obtain the current input signal. The voltage acquisition unit is used to acquire the voltage to be measured output by the operational amplifier and filter the voltage to be measured to obtain a voltage input signal; The analog-to-digital converter is used to convert the current input signal into the current digital signal and the voltage input signal into the voltage digital signal in response to the read signal.
[0012] In some embodiments, the processing module is specifically used for: According to Ohm's law, the resistance value of the resistor to be measured is obtained by dividing the digital voltage signal by the digital current signal.
[0013] In some embodiments, the resistance detection circuit further includes a digital-to-analog converter, which is connected to the constant current electronic load module; The digital-to-analog converter is used to respond to a first control signal from the processing module to control the magnitude of the constant current through the constant current electronic load module.
[0014] In some embodiments, the resistance detection circuit further includes a switching circuit, which is connected to the power module and the resistor to be measured respectively. The switching circuit is used to control the connection between the power supply module and the resistor under test in response to a second control signal from the processing module.
[0015] The embodiments of this application include at least the following beneficial effects: This application provides a resistance value detection circuit, which includes a comparison module, a latch module, a processing module, and an analog-to-digital conversion module. The comparison module acquires the voltage to be measured of the resistor under test and compares it with a preset reference voltage, outputting the comparison result. The latching module outputs an abnormal signal if the comparison result indicates an abnormal state. The processing module responds to the abnormal signal by sending a read signal to the analog-to-digital converter (ADC). The ADC responds to the read signal by sending the digital voltage and current signals of the resistor under test to the processing module. The processing module calculates the resistance value of the resistor under test based on the digital voltage and current signals. This solution determines the range of resistance value variation by setting the reference voltage of the comparator. When the comparison result indicates an abnormal state, indicating that the resistance value exceeds the range, the processing module triggers the ADC to read the abnormal resistance value. This eliminates the need for the ADC to continuously read voltage and current data, reducing the performance requirements of the ADC, minimizing data processing by the processing module, saving computational resources, and improving detection efficiency and accuracy. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the resistance detection circuit provided in the embodiment of this application; Figure 2 This is a schematic diagram of the structure of the connection interface of the resistor under test provided in an embodiment of this application; Figure 3 This is a schematic diagram of the power module provided in an embodiment of this application; Figure 4 This is a schematic diagram of the structure of the constant current electronic load module provided in the embodiments of this application; Figure 5 This is a schematic diagram of the connection between the operational amplifier and the comparator module provided in an embodiment of this application; Figure 6 This is a schematic diagram of the connection between the debouncing filter module and the latch module provided in the embodiments of this application; Figure 7 This is a schematic diagram of the structure of the analog-to-digital converter provided in the embodiments of this application; Figure 8 This is a schematic diagram of the current acquisition unit provided in the embodiments of this application; Figure 9 This is a schematic diagram of the voltage acquisition unit provided in the embodiments of this application; Figure 10 This is a schematic diagram of the structure of the digital-to-analog converter provided in the embodiments of this application; Figure 11 This is a schematic diagram of the switching circuit provided in an embodiment of this application; Figure 12 This is a system schematic diagram of the resistance value detection circuit provided in the embodiments of this application; Figure 13This is a flowchart of the resistance value detection process provided in the embodiments of this application. Detailed Implementation
[0017] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to limit it. In the following description, when referring to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with those of this application; they are merely examples of apparatuses and methods consistent with some aspects of the embodiments of this application as detailed in the appended claims.
[0018] 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 this application belongs. The terminology used herein is for the purpose of describing embodiments of this application only and is not intended to limit this application.
[0019] In related technologies, many DCR (Direct Current Resistance) tests power the product under test (DUT) with a constant current or constant voltage source, then use an ADC to read the sampled current and voltage values, and finally calculate the DCR value. However, for some applications requiring rapid testing or real-time detection, such as swing aging tests or tensile tests where the product's impedance or contact impedance needs to be measured during movement, this dynamic testing method typically uses a fast ADC (Analog-to-Digital Converter) to acquire signals. However, fast ADC acquisition is very expensive, has a high data throughput, and requires high software processing speed, making it unsuitable for applications with high real-time requirements.
[0020] Based on this, this application proposes a resistance value detection circuit, which can reduce the operating burden of the analog-to-digital conversion module and improve detection speed and accuracy.
[0021] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the resistance value detection circuit provided in the embodiment of this application. The resistance value detection circuit includes a comparison module, a latch module, a processing module, and an analog-to-digital conversion module. The comparison module is used to obtain the voltage to be measured of the resistor under test, compare the voltage to be measured with the preset reference voltage, and output the comparison result; The latch module, connected to the comparison module, is used to output an abnormal signal when the comparison result indicates an abnormal state. The processing module, connected to the latch module, is used to send a read signal to the analog-to-digital conversion module in response to an abnormal signal; The analog-to-digital converter module, connected to the processing module, is used to send the voltage and current digital signals of the resistor under test to the processing module in response to the read signal. The processing module is also used to calculate the resistance value of the resistor under test based on the digital voltage signal and the digital current signal.
[0022] Specifically, a change in the resistance of the resistor under test will cause a corresponding change in the voltage under test. The comparison module includes multiple voltage comparators, which can compare the magnitudes of the voltages at two input terminals and output corresponding low-level or high-level signals. Therefore, the comparison result can be represented as a low-level or high-level signal. One input terminal of the voltage comparator receives a stable reference voltage, the magnitude of which is determined by the specific resistance variation range. When the level of the comparison result changes, it indicates that the voltage under test is higher or lower than the reference voltage, thus indicating that the resistance value of the resistor under test exceeds a preset variation range. For example, a high-level comparison result indicates an abnormal state. After receiving a high-level signal, the latch module latches and outputs an abnormal signal, which can be represented as a high-level or low-level signal. After receiving an abnormal signal, the processing module triggers an interrupt and reads the current digital voltage and current signals of the resistor under test through the analog-to-digital converter module to determine the current resistance value of the resistor under test. The processing module can be an MCU (Microcontroller Unit). The analog-to-digital converter module can convert analog voltage or current signals into digital signals. The resistance detection circuit provided in this embodiment significantly optimizes software processing time and reduces hardware costs. When the voltage to be measured exceeds the comparator's reference voltage, the comparator's level changes accordingly, thereby latching the abnormal state through a trigger. Then, the current signal state is obtained through an edge-triggered interrupt by the MCU, and the current and voltage are read by the ADC to obtain the impedance value where the abnormality occurred. Therefore, the software does not need to be in a detection state for a long time to process the signal; interrupt handling is only required when a signal abnormality occurs. This embodiment detects the resistance value in hardware, eliminating the need for software queries. It offers high monitoring efficiency and can detect instantaneous changes in resistance, making it well-suited for scenarios with high real-time requirements.
[0023] In some embodiments, the resistance detection circuit further includes a constant current electronic load module and a power supply module, wherein the power supply module is connected to the first end of the resistor under test and the constant current electronic load module is connected to the second end of the resistor under test. The power module is used to provide an initial voltage to the resistor under test; The constant current electronic load module is used to control the current passing through the resistor under test to be a constant current.
[0024] Specifically, please refer to Figure 2 , Figure 3 and Figure 4 , Figure 2 DUT_CON1 is the connector for the resistor under test (UUT). Connecting the UUT to DUT_CON1 allows monitoring of its resistance value. The connector has four interfaces. In this embodiment, the resistance is tested using the Kelvin four-wire method. SIGNAL_1_F_N represents the negative power input (Force line); SIGNAL_1_S_N represents the negative measurement terminal (Sense line); SIGNAL_1_F_P represents the positive power input (Force line); and SIGNAL_1_S_P represents the positive measurement terminal (Sense line). The Kelvin four-wire method can achieve low-resistance measurement with sub-milliohm accuracy. Figure 3 The circuits in (a) and (b) are power supply modules. They are powered by an external DC power input, and after passing through a power isolation module, the external power supply to the board is isolated. Then, an LDO (low dropout linear regulator) converts the voltage to provide voltage measurement for the resistor under test. The power input uses an isolation method, which can greatly eliminate the influence of external noise interference on the test. Figure 4 The constant current electronic load module is connected to DUT_CON1 via SIGNAL_1_F_N. This module ensures that the current flowing through the resistor under test (UTP) is constant, meaning the current is a fixed value. The UTP is connected to the power supply module via SIGNAL_1_F_P to obtain its initial voltage. Because the current through the UTP is constant, changes in its resistance can be characterized by changes in voltage.
[0025] In some embodiments, the resistance detection circuit further includes an operational amplifier, which is disposed between the comparison module and the resistor to be measured. An operational amplifier is used to obtain the initial voltage across the resistor under test; the initial voltage is amplified to obtain the voltage under test.
[0026] Specifically, please refer to Figure 5 The input terminals of the operational amplifier are connected to SIGNAL_1_S_P and SIGNAL_1_S_N respectively to obtain the initial voltage across the resistor under test. For small resistors, the voltage across them is relatively small. The initial voltage is differentially amplified and common-mode interference is suppressed by inputting a differential signal to operational amplifier U16, and finally the measured voltage V_Meas is output.
[0027] In some embodiments, the comparison module includes a first comparator and a second comparator, and the output terminal of the operational amplifier is connected to the positive input terminal of the first comparator and the negative input terminal of the second comparator, respectively. The negative input terminal of the first comparator is used to obtain the lower limit reference voltage; The positive input terminal of the second comparator is used to obtain the upper limit reference voltage; The first comparator is used to compare the voltage to be measured with the lower limit reference voltage; if the voltage to be measured is less than the lower limit reference voltage, the first comparison result indicating the abnormality is output. The second comparator is used to compare the voltage to be measured with the upper limit reference voltage; if the voltage to be measured is greater than the upper limit reference voltage, the second comparison result indicating an anomaly is output. The reference voltage includes a lower limit reference voltage and an upper limit reference voltage, and the comparison results include a first comparison result and a second comparison result.
[0028] Specifically, please refer to Figure 5 The comparison module U20 includes a first comparator and a second comparator. The voltage to be measured, V_Meas, is input to the positive input terminal (+INB) of the first comparator and the negative input terminal (-INA) of the second comparator. The negative input terminal (+INA) of the first comparator receives the lower limit reference voltage REFL1, and the positive input terminal (-INB) of the second comparator receives the upper limit reference voltage (REFH1). The first comparator compares the voltage to be measured with the lower limit reference voltage and outputs a first comparison result OUT_L1. OUT_L1 determines whether the voltage to be measured exceeds the lower limit of the voltage range, i.e., the resistance value of the resistor to be measured is lower than the lower limit of the resistance variation range. The second comparator compares the voltage to be measured with the upper limit reference voltage and outputs a second comparison result OUT_H1. OUT_H1 determines whether the voltage to be measured exceeds the upper limit of the voltage range, i.e., the resistance value of the resistor to be measured is higher than the upper limit of the resistance variation range. OUT_L1 and OUT_H1 can be high-level signals when indicating an abnormality, and low-level signals when normal.
[0029] In some embodiments, the resistance detection circuit further includes a debounce filter module, the input of which is connected to the output of the comparison module, and the output of which is connected to the input of the latch module. The debouncing filter module is used to filter out interference signals in the comparison results and send the comparison results after filtering out interference signals to the latch module.
[0030] For details, please refer to Figure 6 The debouncing filter module includes two debouncing filters (U24 and U25), which are connected to the outputs of the first and second comparators, respectively. They receive OUT_L1 and OUT_H1 and output OUT_L1 and OUT_H1 after filtering out interference signals. The debouncing filter module can be specifically configured to filter out high-frequency pulse signals, which are considered noise interference. After passing through the debouncing filter module, only valid signals from the circuit will trigger the subsequent latching module. This reduces the risk of false triggering caused by power system waveform or noise interference, improving the reliability and stability of the test.
[0031] In some embodiments, the latch module includes a first latch and a second latch, wherein the first latch is connected to a first comparator and the second latch is connected to a second comparator; The first latch is used to output a first exception signal in response to the first comparison result; The first latch is used to output a second exception signal in response to the second comparison result; The abnormal signals include a first abnormal signal and a second abnormal signal.
[0032] Specifically, please refer to Figure 6 The CLR terminal of the first latch U28 is connected to the output terminal OUT of U24, and the CLR terminal of the second latch U29 is connected to the output terminal OUT of U25. U28 can receive the output OUT_H1 after filtering out interference signals, and U29 can receive the output OUT_L1 after filtering out interference signals. U28 and U29 can be D flip-flops. If OUT_H1 is a high-level signal, U28 is triggered to latch, outputting a first abnormal signal, indicating that the resistance value is greater than the upper limit. If OUT_L1 is a high-level signal, U29 is triggered to latch, outputting a second abnormal signal, indicating that the resistance value is less than the lower limit. When U28 or U29 is triggered, the output terminals will change level. For example, U28 and U29 normally output a low level. After an abnormality occurs and they are triggered, they respectively output a first abnormal signal and a second abnormal signal to the processing module. The first and second abnormal signals can be high-level signals. At the instant the signal level of the latch output changes, the processing module triggers an interrupt and reads the voltage digital signal and current digital signal from the analog-to-digital converter module.
[0033] In some embodiments, the analog-to-digital conversion module includes a current acquisition unit, a voltage acquisition unit, and an analog-to-digital converter. The current acquisition unit is connected to a constant current electronic load module, and the voltage acquisition unit is connected to an operational amplifier. The current acquisition unit is used to acquire the differential current signal output by the constant current electronic load module and amplify the differential current signal to obtain the current input signal. The voltage acquisition unit is used to acquire the voltage to be measured output from the operational amplifier and filter the voltage to be measured to obtain the voltage input signal; An analog-to-digital converter is used to convert a current input signal into a digital current signal and a voltage input signal into a digital voltage signal in response to a read signal.
[0034] Specifically, please refer to Figures 7-9 , Figure 8The input terminals (IN+ and IN-) of the current acquisition unit are connected to the constant current electronic load module to receive differential current signals I_Meas+ and I_Meas-. Since the amplitudes of I_Meas+ and I_Meas- are small, the weak signals need to be amplified, and common-mode interference in the environment needs to be suppressed before outputting the current input signal AD0In. Figure 9 The input terminal (+IN) of the voltage acquisition unit is connected to the output terminal OUTA of the operational amplifier to receive the voltage to be measured V_Meas. V_Meas is isolated and driven to enhance the signal, providing a stable, low-noise voltage input signal AD1In for the ADC. Figure 9 This is a schematic diagram of the analog-to-digital converter. Figure 7 In the diagram, (a) is the analog-to-digital converter chip, (b) and (c) are the ADC input overvoltage protection (OVP) circuits, and (d) is the voltage reference circuit. The current input signal AD0In and the voltage input signal AD1In pass through the ADC input overvoltage protection circuit to protect the ADC input pins and prevent damage due to overvoltage. Finally, they are input to AIN0 and AIN1 of U43. The voltage reference circuit provides U43 with a high-precision 4.096V reference voltage (Vref_4V096) as a stable reference. U43 converts the analog signals (current input signal and voltage input signal) into digital signals (digital current signal and digital voltage signal) and sends them to the processing module via SPI communication.
[0035] In some embodiments, the processing module is specifically used for: According to Ohm's law, the resistance value of the resistor to be measured is obtained by dividing the digital voltage signal by the digital current signal.
[0036] Specifically, after receiving the digital voltage and current signals, the processing module calculates the corresponding resistance values according to Ohm's law. The processing module can then transmit the data to a display via serial communication for user convenience.
[0037] In some embodiments, the resistance detection circuit further includes a digital-to-analog converter, which is connected to a constant current electronic load module. A digital-to-analog converter is used to control the magnitude of a constant current via a constant current electronic load module.
[0038] Specifically, please refer to Figure 10The input of the digital-to-analog converter (DAC) is connected to the processing module, communicating via SPI. The outputs OUT0 and OUT1 are connected to the comparator module, outputting upper limit reference voltage REFH1 and lower limit reference voltage REFL1 respectively, serving as the reference voltages for the comparator module. Output OUT2 is connected to the constant current electronic load module. The processing module sends control commands to U42 via SPI communication. U42 responds to the control commands by controlling the magnitude of the constant current or changing the values of REFL1 and REFH1 through CC1_Set. The DAC can control the magnitude of the constant current, setting different constant current values for different resistors under test to adapt to different products.
[0039] In some embodiments, the resistance detection circuit further includes a switching circuit, which is connected to the power module and the resistor to be measured respectively. The switching circuit is used to control the connection between the power supply module and the resistor under test in response to a second control signal from the processing module.
[0040] Specifically, please refer to Figure 11 K1 can be a relay switch. Pin 6 of the relay switch receives the PP2V_1 power output from the power module. Pin 4 of the relay is connected to the SIGNAL_1_F_P of the resistor under test. The processing module controls the relay switch through the control signal CH1_PWR_EN, thereby controlling the on / off state between pin 6 and pin 4, and thus controlling whether to supply power to the resistor under test.
[0041] In some embodiments, please refer to Figure 12 The DUT represents the resistor under test. A power supply module and a constant current electronic load module are connected to the two ends of the DUT to provide voltage and control current. An operational amplifier's input is connected to the two ends of the DUT to read its voltage. The voltage is amplified and output to two comparators. The two comparators compare a reference voltage with the amplified voltage and output the comparison result to determine whether the DUT exceeds the upper or lower limit of its resistance variation range. The two outputs are debouncing filtered and then transmitted to two latches. In response to abnormal comparison results, the latches trigger a level change, causing the MCU to terminate, thereby reading the current voltage and current values of the DUT and determining its current resistance.
[0042] In some embodiments, please refer to Figure 13In the testing process, each module in the resistance detection circuit is first initialized. The reference voltage of the comparator is set through the digital-to-analog converter, and the magnitude of the Eload current through the resistor under test is set. Then, the state of the trigger is reset. After the resistor under test is powered on, the comparator compares the voltage under test amplified by the operational amplifier with the reference voltage. If the voltage under test does not exceed the range of the reference voltage, it continues to monitor. If the voltage under test exceeds the range of the reference voltage, the latch is triggered to latch the abnormal signal, causing the MCU to trigger an interrupt, thereby reading the abnormal resistance value.
[0043] The embodiments of this application have at least one of the following beneficial effects: It can accurately and reliably detect changes in resistance and precisely set the threshold for resistance changes. When the resistance change exceeds the reference value, it can latch whether the resistance change exceeds the lower or upper limit. Then, it reads the voltage and current values at the time of the abnormality through the ADC, calculates and records the abnormal resistance value. The resistance value is detected by hardware, eliminating the need for software queries. This method offers high monitoring efficiency and can detect even instantaneous changes in resistance. Adding a debounce filter circuit to the circuit can improve the reliability and stability of the test by addressing the problem of false triggering caused by power system waveform or noise interference. It offers high real-time performance, fast detection speed, and high detection accuracy, providing an optimal solution for monitoring impedance changes. It can flexibly monitor different impedances and precisely control the constant current load current value to adapt; When the impedance changes beyond the reference value, the ADC is triggered to measure the abnormal resistance value. This eliminates the need to continuously read the impedance value, reducing the processing burden on the MCU and decreasing the use of hardware resources, thereby improving testing efficiency and accuracy.
[0044] The embodiments described in this application are for the purpose of more clearly illustrating the technical solutions of this application, and do not constitute a limitation on the technical solutions provided in this application. As those skilled in the art will know, with the evolution of technology and the emergence of new application scenarios, the technical solutions provided in this application are also applicable to similar technical problems.
[0045] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.
[0046] The terms “first,” “second,” “third,” “fourth,” etc. (if present) in the specification and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.
[0047] It should be understood that in this application, "at least one (item)" means one or more, and "more than" means two or more. "And / or" is used to describe the relationship between related objects, indicating that three relationships can exist. For example, "A and / or B" can represent three cases: only A exists, only B exists, and both A and B exist simultaneously, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one (item) of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one (item) of a, b, or c can represent: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, and c can be single or multiple.
[0048] In the several embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of the above-mentioned units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.
[0049] The units described above as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of these units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
[0050] The preferred embodiments of the present application have been described above with reference to the accompanying drawings, but this does not limit the scope of the claims of the present application. Any modifications, equivalent substitutions, and improvements made by those skilled in the art without departing from the scope and substance of the embodiments of the present application shall be within the scope of the claims of the present application.
Claims
1. A resistance value detection circuit, characterized in that, The resistance value detection circuit includes a comparison module, a latch module, a processing module, and an analog-to-digital conversion module; The comparison module is used to obtain the voltage to be measured of the resistor under test, compare the voltage to be measured with a preset reference voltage, and output the comparison result. The latch module is connected to the comparison module, and the latch module is used to output an abnormal signal when the comparison result indicates an abnormal state. The processing module is connected to the latch module, and the processing module is used to send a read signal to the analog-to-digital conversion module in response to the abnormal signal; The analog-to-digital conversion module is connected to the processing module, and the analog-to-digital conversion module is used to send the voltage digital signal and current digital signal of the resistor under test to the processing module in response to the read signal. The processing module is also used to calculate the resistance value of the resistor under test based on the voltage digital signal and the current digital signal.
2. The resistance detection circuit according to claim 1, characterized in that, The resistance detection circuit further includes a constant current electronic load module and a power supply module. The power supply module is connected to the first terminal of the resistor under test, and the constant current electronic load module is connected to the second terminal of the resistor under test. The power module is used to provide an initial voltage to the resistor under test; The constant current electronic load module is used to control the current passing through the resistor under test to be a constant current.
3. The resistance detection circuit according to claim 2, characterized in that, The resistance detection circuit further includes an operational amplifier, which is disposed between the comparison module and the resistor to be measured. The operational amplifier is used to acquire the initial voltage across the resistor under test; the initial voltage is amplified to obtain the voltage under test.
4. The resistance detection circuit according to claim 3, characterized in that, The comparison module includes a first comparator and a second comparator, and the output terminal of the operational amplifier is connected to the positive input terminal of the first comparator and the negative input terminal of the second comparator, respectively. The negative input terminal of the first comparator is used to obtain the lower limit reference voltage; The positive input terminal of the second comparator is used to obtain the upper limit reference voltage; The first comparator is used to compare the magnitude of the voltage to be measured with the lower limit reference voltage; If the voltage to be measured is less than the lower limit reference voltage, output the first comparison result indicating the anomaly; The second comparator is used to compare the voltage to be measured with the upper limit reference voltage; If the voltage to be measured is greater than the upper limit reference voltage, a second comparison result indicating an anomaly is output. The reference voltage includes the lower limit reference voltage and the upper limit reference voltage, and the comparison result includes the first comparison result and the second comparison result.
5. The resistance detection circuit according to claim 1, characterized in that, The resistance detection circuit further includes a debounce filter module, the input of which is connected to the output of the comparison module, and the output of which is connected to the input of the latch module. The debouncing filter module is used to filter out interference signals in the comparison result and send the comparison result after filtering out interference signals to the latch module.
6. The resistance detection circuit according to claim 4, characterized in that, The latch module includes a first latch and a second latch, wherein the first latch is connected to the first comparator and the second latch is connected to the second comparator; The first latch is used to output a first exception signal in response to the first comparison result; The first latch is used to output a second exception signal in response to the second comparison result; The abnormal signals include a first abnormal signal and a second abnormal signal.
7. The resistance detection circuit according to claim 3, characterized in that, The analog-to-digital conversion module includes a current acquisition unit, a voltage acquisition unit, and an analog-to-digital converter. The current acquisition unit is connected to the constant current electronic load module, and the voltage acquisition unit is connected to the operational amplifier. The current acquisition unit is used to acquire the differential current signal output by the constant current electronic load module and amplify the differential current signal to obtain the current input signal. The voltage acquisition unit is used to acquire the voltage to be measured output by the operational amplifier and filter the voltage to be measured to obtain a voltage input signal; The analog-to-digital converter is used to convert the current input signal into the current digital signal and the voltage input signal into the voltage digital signal in response to the read signal.
8. The resistance detection circuit according to claim 1, characterized in that, The processing module is specifically used for: According to Ohm's law, the resistance value of the resistor to be measured is obtained by dividing the digital voltage signal by the digital current signal.
9. The resistance detection circuit according to claim 2, characterized in that, The resistance detection circuit also includes a digital-to-analog converter, which is connected to the constant current electronic load module. The digital-to-analog converter is used to respond to a first control signal from the processing module to control the magnitude of the constant current through the constant current electronic load module.
10. The resistance detection circuit according to claim 2, characterized in that, The resistance detection circuit also includes a switching circuit, which is connected to the power module and the resistor to be measured. The switching circuit is used to control the connection between the power supply module and the resistor under test in response to a second control signal from the processing module.