Resistance value correction circuit and correction method

Abstract

The invention relates to the technical field of integrated circuits, and provides a resistor resistance value correction circuit and correction method. The resistor resistance value correction circuit comprises a reference resistor selection unit, an adjustable constant current source and an analog-to-digital conversion unit, a signal branch of a resistor to be corrected and a target reference resistor corresponding to the resistor to be corrected is constructed through a reference resistor selection unit, and a corresponding target signal current is provided for the constructed signal branch through an adjustable constant current source. The analog-to-digital conversion unit is used for collecting voltages at the two ends of the target reference resistor and the resistor to be corrected in the constructed signal branch to obtain a target reference voltage and a target input voltage respectively, and then the corrected resistance value of the resistor to be corrected is determined based on the target reference voltage and the target input voltage. The circuit can efficiently and conveniently realize the correction of the resistors requiring high-precision resistance values, such as precision resistors, so that the working precision of the resistors when the resistors are used for providing high-precision resistance signal sources and other scenes is improved, and the working performance of related circuits is improved.

Description

Technical Field

[0001] The present application relates to the technical field of integrated circuits, and in particular to a resistor value correction circuit and correction method. Background Art

[0002] As the signal source in the production and testing process of thermistor temperature detection modules, the high-precision resistance signal source must have the characteristics of high precision and good stability to ensure that the accuracy index of the factory module meets the requirements. In practice, due to the limitation of hardware device characteristics, the initial accuracy of the high-precision thermal resistance temperature detection module to be tested cannot meet the accuracy index requirements. It needs to be calibrated first and then tested to ensure that the accuracy index of the module to be tested meets the requirements.

[0003] In the production process, multiple precision resistors are usually required for calibration and inspection. The multiple precision resistors can be connected to the high-precision thermal resistor temperature detection module by manual installation or by probe. The former requires manual participation and is therefore inefficient. The latter requires a wire to be connected between the probe and the switching board loaded with precision resistors, and the relay contacts and probe impedance change slowly and irregularly over time, so the obtained resistance signal source has poor accuracy and stability. Summary of the invention

[0004] In view of this, an embodiment of the present application provides a resistor value correction circuit and correction method to solve the problem in the prior art that a high-precision resistor signal source cannot be efficiently calibrated.

[0005] According to a first aspect of an embodiment of the present application, a resistor value correction circuit is provided, comprising:

[0006] Reference resistor selection unit, adjustable constant current source and analog-to-digital conversion unit;

[0007] The reference resistance selection unit selects a target reference resistance based on the resistance to be corrected of the resistance value correction circuit;

[0008] The adjustable constant current source provides a target signal current for the target reference resistor and the resistor to be corrected;

[0009] The analog-to-digital conversion unit is used to determine a target reference voltage based on a target signal current and a target reference resistance, determine a target input voltage based on a target signal current and a resistance to be corrected, and determine a correction resistance value of the resistance to be corrected based on the target reference voltage and the target input voltage.

[0010] In one implementation, the analog-to-digital conversion unit includes N pairs of reference signal ports and a pair of input signal ports, where N is a positive integer greater than 1;

[0011] Wherein, each pair of reference signal ports includes a first reference port and a second reference port, the first reference port is used to collect a positive reference signal, and the second reference port is used to collect a negative reference signal;

[0012] The input signal port includes a first input port and a second input port, the first input port is used to collect a positive input signal, and the second input port is used to collect a negative input signal.

[0013] In one embodiment, the reference resistor selection unit is composed of N relays and N reference resistors, the N relays correspond to the N reference resistors one-to-one, and the N pairs of reference signal ports also correspond to the N reference resistors one-to-one;

[0014] Among them, among the N relays, a first end of each relay is connected to a first end of a corresponding reference resistor in a double-contact parallel manner, and a second end is connected to an output end of an adjustable constant current source;

[0015] Among the N reference resistors, the first end of each reference resistor is also connected to the first reference port of the corresponding reference signal port pair, and the second end is connected to the second reference port of the corresponding reference signal port pair and connected to the first end of the resistor to be corrected.

[0016] In one embodiment, the reference resistor selection unit is composed of two relays and N reference resistors, wherein the first relay is connected in series with N / two reference resistors, the second relay is connected in series with the remaining N / two reference resistors, and the N pairs of reference signal ports correspond one to one with the N reference resistors;

[0017] In the two relays, a first end of each relay is connected to a first end of a reference resistor in a double-contact parallel manner, and a second end is connected to an output end of an adjustable constant current source;

[0018] Among the N / two reference resistors connected in series, the first section of each reference resistor is connected to the first reference port of the corresponding reference signal port pair, and the second end is connected to the second reference port of the corresponding reference signal port pair, and the first end of the first reference resistor is also connected to the corresponding relay, and the second end of the last reference resistor is also connected to the first end of the resistor to be corrected.

[0019] In one implementation, the adjustable constant current source includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a load resistor, an operational amplifier, and a digital-to-analog conversion unit;

[0020] A first end of the first resistor is grounded, and a second end is connected to the negative input terminal of the operational amplifier;

[0021] A first end of the second resistor is connected to the output end of the digital-to-analog conversion unit, and a second end is connected to the positive input end of the operational amplifier;

[0022] A first end of the third resistor is connected to the second end of the first resistor, a second end of the third resistor is connected to the output end of the operational amplifier, and is connected to the first end of the fifth resistor;

[0023] A first end of the fourth resistor is connected to the second end of the second resistor, and a second end of the fourth resistor is connected to the second end of the fifth resistor;

[0024] The first end of the load resistor is connected to the second end of the fifth resistor, and the second end is grounded;

[0025] The digital-to-analog conversion unit receives the digital control signal and outputs a corresponding output voltage, so that the adjustable constant current source generates a current corresponding to the target signal based on the output voltage;

[0026] The digital control signal is one of N digital control signals, and the N control signals correspond to the N reference resistors one by one.

[0027] In one implementation, the resistor value correction circuit further includes a bias resistor;

[0028] The first end of the bias resistor is connected to the resistor to be corrected, and the second end is grounded.

[0029] In a second aspect of an embodiment of the present application, a resistance signal source circuit is provided, the resistance signal source circuit comprising an initial resistance signal source circuit and a resistance value correction circuit;

[0030] The initial resistance signal source circuit includes a plurality of relays and precision resistors connected in series;

[0031] In the relays and precision resistors connected in series, the first end of each relay is connected to the first probe, the second end is connected to the first end of the corresponding precision resistor, and the second end of each precision resistor is connected to the second probe;

[0032] The resistor value correction circuit is a resistor value correction circuit as described in any one of the first aspects, wherein the first probe is connected to a first input port of the input signal port of the analog-to-digital conversion unit, and the second probe is connected to a second input port of the input signal port of the analog-to-digital conversion unit.

[0033] According to a third aspect of the embodiments of the present application, a method for correcting the resistance value of a resistor is provided. The method is performed by the resistor value correction circuit provided by the first aspect, and includes:

[0034] Determine a resistance to be corrected, and select a target reference resistance from a reference resistance selection unit based on the resistance to be corrected;

[0035] Use an adjustable constant current source to provide a target signal current for a target reference resistor and a resistor to be corrected;

[0036] Using an analog-to-digital conversion unit to obtain a target reference voltage from a target reference resistor and a target input voltage from a resistor to be corrected;

[0037] determining a first calibration coefficient based on a target reference voltage and a target input voltage;

[0038] Based on the first calibration coefficient and the resistance value of the target reference resistor, a correction resistance value of the resistor to be corrected is determined.

[0039] In one implementation, determining a first calibration coefficient based on a target reference voltage and a target input voltage includes:

[0040] Read the acquisition code value of the target input voltage, which is used to represent the proportional relationship between the target input voltage and the target reference voltage;

[0041] Determine a ratio of the acquisition code value to the resolution of the analog-to-digital conversion unit as a first calibration coefficient;

[0042] The step of determining the correction resistance value of the resistor to be corrected based on the first calibration coefficient and the resistance value of the target reference resistor includes:

[0043] The product of the first calibration coefficient and the resistance value of the target reference resistor is determined as the correction resistance value of the resistor to be corrected.

[0044] A fourth aspect of the embodiments of the present application provides a method for calibrating a thermal resistor temperature detection module, comprising:

[0045] Provide a high-precision resistance signal source for the thermal resistance temperature detection module through the probe;

[0046] Using the resistance value correction circuit as described in any one of the first aspects to correct the high-precision resistance signal source, to obtain a corrected high-precision resistance signal source;

[0047] Collect a first collected resistance value of a thermal resistance temperature detection module;

[0048] Calculating a second calibration coefficient based on the first collected resistance value and the corrected resistance value of the high-precision resistance signal source;

[0049] The thermal resistance temperature detection module is calibrated using the second calibration coefficient.

[0050] According to a fifth aspect of the embodiments of the present application, a method for testing a thermal resistor temperature detection module is provided, comprising:

[0051] Provide a high-precision resistance signal source for the thermal resistance temperature detection module through the probe;

[0052] Using the resistance value correction circuit as described in any one of the first aspects to correct the high-precision resistance signal source, to obtain a corrected high-precision resistance signal source;

[0053] Collect a second collected resistance value of the thermal resistance temperature detection module;

[0054] The second collected resistance value is compared with the resistance value of the corrected high-precision resistance signal source, and in response to the comparison result being less than or equal to a preset threshold, it is determined that the thermal resistance temperature detection module has passed the inspection.

[0055] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the embodiments of the present application provide a resistor value correction circuit, which includes a reference resistor selection unit, an adjustable constant current source, and an analog-to-digital conversion unit; a signal branch of a resistor to be corrected and a target reference resistor corresponding thereto is constructed by the reference resistor selection unit, a corresponding target signal current is provided to the constructed signal branch by the adjustable constant current source, and the voltages at both ends of the target reference resistor and the resistor to be corrected are collected in the constructed signal branch by the analog-to-digital conversion unit, and a target reference voltage and a target input voltage are obtained respectively, and then the corrected resistance value of the resistor to be corrected is determined based on the target reference voltage and the target input voltage. The circuit can efficiently and conveniently realize the correction of resistors that require high-precision resistance values, such as precision resistors, thereby improving the working accuracy of such resistors when used in scenarios such as providing high-precision resistor signal sources, and improving the working performance of related circuits. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, 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 only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0057] Figure 1 It is a scenario diagram of an application scenario of an embodiment of the present application.

[0058] Figure 2 It is a structural schematic diagram of a resistor value correction circuit provided in an embodiment of the present application.

[0059] Figure 3 It is a structural schematic diagram of another resistor value correction circuit provided in an embodiment of the present application.

[0060] Figure 4 It is a structural schematic diagram of an adjustable constant current source provided in an embodiment of the present application.

[0061] Figure 5 It is a flow chart of a method for determining a correction resistance value of a resistor to be corrected provided in an embodiment of the present application.

[0062] Figure 6It is a structural schematic diagram of a resistance signal source circuit provided in an embodiment of the present application.

[0063] Figure 7 It is a flow chart of a resistor value correction method provided in an embodiment of the present application.

[0064] Figure 8 It is a flow chart of a calibration method of a thermal resistor temperature detection module provided in an embodiment of the present application.

[0065] Fig. 9 It is a flow chart of a method for inspecting a thermal resistor temperature detection module provided in an embodiment of the present application.

[0066] Fig.10 It is a schematic diagram of an electronic device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0067] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0068] A resistor value correction circuit and method according to an embodiment of the present application will be described in detail below with reference to the accompanying drawings.

[0069] As mentioned above, in the actual production process, the high-precision thermistor temperature detection module to be tested needs to be calibrated first, then inspected, and then can be used to ensure that the accuracy index of the module to be tested meets the requirements.

[0070] Figure 1 Schematic diagram of an application scenario of an embodiment of the present application. The application scenario may include a high-precision thermal resistance detection module, a resistance signal source, a terminal device and a communication bus.

[0071] The high-precision thermal resistance detection module is a module to be calibrated and verified, and a high-precision resistance signal source is required during calibration and verification.

[0072] The resistance signal source module provides a high-precision resistance signal source for the high-precision thermal resistance detection module. In the production process, the calibration and inspection of the high-precision thermal resistance detection module usually require two precision resistors with a total of four resistance values, such as Figure 1The resistors R1 and R2 in the figure can be used as a set of calibration resistors, and the resistors R3 and R4 can be used as a set of test resistors. The resistance values ​​of the four resistors will be used as standard resistance values ​​and stored locally in the test equipment computer. The calibration and test processes use this standard value for calculation. The resistance test range of the thermal resistor detection module is usually 0 ohms (Ω) to 4 kilo-ohms (kΩ). Usually two resistors are provided in the resistance signal source module for calibration, and another two resistors are provided for testing. The two resistance values ​​used for calibration are usually 200Ω and 3.6kΩ, and the two resistance values ​​used for testing are usually 100Ω and 3kΩ.

[0073] Further, such as Figure 1 As shown, each resistor in the resistance signal source module is connected to a relay, wherein resistor R1 is connected to relay RL1, resistor R2 is connected to relay RL2, resistor R3 is connected to relay RL3, and resistor R4 is connected to relay RL4. At the same time, the other end of each relay and the other end of each resistor are respectively connected to probes, and the probes are connected to corresponding terminals in the high-precision thermal resistor detection module.

[0074] During the production process, the standard resistance values ​​of the two calibration resistors and the collected values ​​of the module to be tested can be used to perform calculations as required, and the calculated calibration coefficients will be stored in the module to be tested. This process is called calibration. The standard resistance values ​​of the two inspection resistors and the collected values ​​of the module to be tested are used to calculate the error to determine whether the module accuracy meets the requirements. This process is called inspection. Among them, the selection of resistors and part of the calculation can be implemented in the terminal device, and the terminal device is connected to the resistance signal source module and the high-precision thermal resistor detection module through a communication bus. Furthermore, the resistance signal source module can also include a communication conversion control circuit, which receives the conversion instruction sent by the terminal device, controls the conduction and disconnection of the relay, and then selects the corresponding high-precision resistor.

[0075] The terminal device can be hardware or software. When the terminal device is hardware, it can be various electronic devices with a display screen and supporting communication with the resistance signal source module and the high-precision thermal resistance detection module, including but not limited to smart phones, tablet computers, laptops, desktop computers, and servers; when the terminal device is software, it can be installed in the electronic devices described above. The terminal device can be implemented as multiple software or software modules, or as a single software or software module, and the embodiments of the present application are not limited to this.

[0076] There are two main ways to provide resistance signal sources in the existing production test process. One is to manually install precision resistors on the module to be tested. This method has high accuracy, but it is inefficient because it requires manual participation. The other is to provide resistance signal sources through probes. The probe head contacts the terminal of the module to be tested, and the tail is connected to a relay and a switching board of precision resistors through a wire. Each precision resistor is connected in series with a relay and then in parallel to the two ends of the probe. When in use, the required resistance signal source is automatically switched through the relay as needed. Although this method is efficient, the accuracy and stability of the resistance signal source are relatively poor due to the connection wire between the probe and the switching board, as well as the change in the impedance of the relay contact and the probe. The contact impedance of the relay contact and the probe is about 100mΩ, and it changes slowly and irregularly over time. This problem will cause the resistance error of the signal source to be more than 0.2% when the resistance value is small, which cannot meet the high-precision use requirements.

[0077] In view of this, the embodiment of the present application provides an automatically switched high-precision resistance signal source, which consists of a high-precision resistance signal source and a standard high-precision resistance detection module. The high-precision resistance signal source is used to switch through a relay to provide a precision resistance signal source with different resistance values. The standard high-precision resistance detection module is used to complete the software correction of the high-precision resistance signal source to ensure the stability and reliability of the accuracy of the high-precision resistance signal source.

[0078] Furthermore, the embodiment of the present application also provides a resistor value correction circuit, which includes a reference resistor selection unit, an adjustable constant current source and an analog-to-digital conversion unit; a signal branch of a resistor to be corrected and a target reference resistor corresponding thereto is constructed by the reference resistor selection unit, a corresponding target signal current is provided to the constructed signal branch by the adjustable constant current source, and the voltages at both ends of the target reference resistor and the resistor to be corrected are collected in the constructed signal branch by the analog-to-digital conversion unit to obtain a target reference voltage and a target input voltage, respectively, and then the corrected resistance value of the resistor to be corrected is determined based on the target reference voltage and the target input voltage. The circuit can efficiently and conveniently realize the correction of resistors that require high-precision resistance values, such as precision resistors, thereby improving the working accuracy of such resistors when used in scenarios such as providing high-precision resistor signal sources, and improving the working performance of related circuits.

[0079] Figure 2 Schematic diagram of a resistor value correction circuit provided in an embodiment of the present application. Figure 2 As shown, the resistance value correction circuit includes a reference resistance selection unit 1, an adjustable constant current source 2 and an analog-to-digital conversion unit 3. Further, the resistance value correction circuit is connected to the resistor to be corrected 5. The resistor to be corrected 5 can be a resistor in a high-precision resistance signal source, or other resistors that need to be corrected for high-precision resistance value, which is not limited here.

[0080] The reference resistor selection unit 1 is used to select a target reference resistor based on the resistor to be corrected 5 of the resistance value correction circuit. That is, a suitable target reference resistor can be selected according to the determined resistor to be corrected 5, and then the information of the selected target reference resistor is sent to the reference resistor selection unit 1, so that the reference resistor selection unit 1 controls the branch where the selected target reference resistor is located to be turned on.

[0081] In one example, if the resistance value correction circuit is used to correct the signal source resistance that provides a high-precision resistance signal source for a high-precision thermal resistor detection module, and the two resistance values ​​used for calibration in the high-precision thermal resistor detection module are 200Ω and 3.6kΩ, and the two resistance values ​​used for verification are 100Ω and 3kΩ, then the resistance values ​​of the resistors to be corrected can be 200Ω, 3.6kΩ, 100Ω, and 3kΩ. Further, in order to improve the correction accuracy, two reference resistors can be set, which are 220Ω and 3.9kΩ, respectively, wherein the 220Ω reference resistor is used as the reference reference resistor for the 100Ω and 200Ω resistors to be corrected, and the 3.9kΩ reference resistor is used as the reference reference resistor for the 3kΩ and 3.6kΩ resistors to be corrected. When correcting the resistance values ​​of the resistors to be corrected of 100Ω and 200Ω, the reference resistor selection unit can select a reference resistor with a target reference resistance of 220Ω; when correcting the resistance values ​​of the resistors to be corrected of 3kΩ and 3.6kΩ, the reference resistor selection unit can select a reference resistor with a target reference resistance of 3.9kΩ.

[0082] In the embodiment of the present application, the adjustable constant current source 2 is used to provide a target signal current for the target reference resistor and the resistor to be corrected. The output path of the constant current source includes the target reference resistor and the resistor to be corrected. Further, the output path may also include a bias resistor 4, one end of which is connected to the circuit to be corrected and the other end is grounded to form a complete current loop.

[0083] In an embodiment of the present application, the analog-to-digital conversion unit 3 is used to determine the target reference voltage based on the target signal current and the target reference resistance, and to determine the target input voltage based on the target signal current and the resistance to be corrected. Finally, the corrected resistance value of the resistance to be corrected is determined based on the determined target reference voltage and the target input voltage. In other words, the analog-to-digital conversion unit 3 collects the voltage across the target reference resistance as the target reference voltage. At the same time, the voltage across the resistance to be corrected is collected as the target input voltage. Afterwards, the analog-to-digital conversion unit calculates the proportional relationship between the target reference voltage and the target input voltage, and the proportional relationship between the target reference voltage and the target input voltage can also be the proportional relationship between the target reference resistance and the resistance value of the resistance to be corrected. Finally, the proportional relationship is calculated with the target reference resistance to obtain the corrected resistance value of the resistance to be corrected.

[0084] According to the technical solution provided in the embodiment of the present application, a signal branch of the resistor to be corrected and the target reference resistor corresponding thereto is constructed through a reference resistor selection unit, a corresponding target signal current is provided to the constructed signal branch through an adjustable constant current source, and the voltages at both ends of the target reference resistor and the resistor to be corrected are collected in the constructed signal branch through an analog-to-digital conversion unit to obtain a target reference voltage and a target input voltage, respectively, and then the corrected resistance value of the resistor to be corrected is determined based on the target reference voltage and the target input voltage. The circuit can efficiently and conveniently realize the correction of resistors such as precision resistors that require high-precision resistance values, thereby improving the working accuracy of such resistors when used in scenarios such as providing high-precision resistance signal sources, and improving the working performance of related circuits.

[0085] Figure 3 is a schematic diagram of the structure of another resistor value correction circuit provided in an embodiment of the present application. Figure 3 As shown, the resistance value correction circuit also includes a reference resistance selection unit 1, an adjustable constant current source 2 and an analog-to-digital conversion unit 3. Among them, the analog-to-digital conversion unit includes two pairs of reference signal ports and a pair of input signal ports. In some embodiments, the number of reference signal port pairs can be expanded according to actual needs, for example, set to three pairs, four pairs, etc. That is, the analog-to-digital conversion unit 3 can include N pairs of reference signal ports, and N is a positive integer greater than 1.

[0086] In the embodiment of the present application, each pair of reference signal ports includes a first reference port and a second reference port, wherein the first reference port is used to collect a positive reference signal, and the second reference port is used to collect a negative reference signal. Figure 3 As shown, the first reference signal port pair includes first reference ports REF0+ and REF0-, REF0+ is used to collect positive reference signals, and REF0- is used to collect negative reference signals. Similarly, the second reference signal port pair also includes first reference ports REF1+ and REF1-, REF1+ is used to collect positive reference signals, and REF1- is used to collect negative reference signals.

[0087] In the embodiment of the present application, the input signal port also includes a first input port and a second input port, wherein the first input port is used to collect positive input signals, and the second input port is used to collect negative input signals. Figure 3 As shown, the first reference signal port pair includes first reference ports AIN+ and AIN-, AIN+ is used to collect positive reference signals, and AIN- is used to collect negative reference signals.

[0088] In the embodiment of the present application, the reference resistor selection unit 1 may be composed of N relays and N reference resistors, the N relays correspond to the N reference resistors one by one, and the N pairs of reference signal ports also correspond to the N reference resistors one by one. Figure 3As shown, the reference resistor selection unit 1 is composed of two relays RL5 and RL6, and two reference resistors R5 and R6, wherein the relays RL5 and RL6 correspond to the reference resistors R5 and R6 one by one, and the reference signal ports (REF0+, REF0-) and (REF1+, REF1-) also correspond to the reference resistors R5 and R6 one by one. That is to say, when the relay RL5 is turned on, the output current mirror reference resistor R5 of the adjustable constant current source 2 flows to the resistor to be corrected 5, and finally grounded through the bias resistor 4.

[0089] The first end of each relay in the reference resistor selection unit 1 is connected to the first end of the corresponding reference resistor in a double-contact parallel connection mode, which can reduce the error introduced by the contact impedance compared to the single-contact contact mode. The second end of the relay is connected to the output end of the adjustable constant current source 2. Further, the first end of each reference resistor is also connected to the first reference port of the corresponding reference signal port pair, and the second end of the reference resistor is connected to the second reference port of the corresponding reference signal port pair, and is connected to the first end of the resistor to be corrected.

[0090] In an embodiment of the present application, the reference resistor selection unit 1 can also be composed of two relays and N reference resistors, wherein the first relay is connected in series with N / two reference resistors, the second relay is connected in series with the remaining N / two reference resistors, and the N pairs of reference signal ports correspond one-to-one to the N reference resistors.

[0091] Further, in the two relays, the first end of each relay is connected to the first end of a reference resistor in a double-contact parallel manner, and the second end is connected to the output end of the adjustable constant current source 2. In the N / two reference resistors connected in series, the first section of each reference resistor is connected to the first reference port of the corresponding reference signal port pair, the second end is connected to the second reference port of the corresponding reference signal port pair, and the first end of the first reference resistor is also connected to the corresponding relay, and the second end of the last reference resistor is also connected to the first end of the resistor to be corrected.

[0092] That is to say, when the number of resistors to be corrected is large and the difference between the resistance values ​​of each resistor is large, the number of reference resistors used as a reference may need to be more than two. At this time, the number of parallel branches consisting of relays and reference resistors mentioned above can be used for expansion. However, the increase in the number of parallel branches may lead to a decrease in detection accuracy, and then to a decrease in the accuracy of resistor resistance correction. In view of this, the embodiment of the present application proposes another reference resistor selection unit 1, in which the parallel branch consisting of two relays is still maintained, and in each branch where a relay is located, multiple reference resistors can be connected in series, and different reference resistors are connected to the first port and the second port of different reference signal port pairs in the analog-to-digital conversion unit 3, so that the analog-to-digital conversion unit 3 can collect the reference voltage of each reference resistor, and the last resistor in the series branch is also connected in series with the resistor to be corrected, so that the analog-to-digital conversion unit 3 can collect the input voltage. In this way, the number and type of resistors to be corrected can be expanded on the basis of ensuring a certain detection accuracy, and the scope of application of the circuit can be expanded.

[0093] Figure 4 Schematic diagram of an adjustable constant current source provided in an embodiment of the present application. Figure 4 As shown, the adjustable constant current source 2 includes a first resistor R7, a second resistor R8, a third resistor R9, a fourth resistor R10, a fifth resistor R11, a load resistor Rc, an operational amplifier and a digital to analog conversion unit (DAC). Wherein, the first end of the first resistor R7 is grounded, and the second end is connected to the negative input terminal of the operational amplifier. The first end of the second resistor R8 is connected to the output terminal of the digital to analog conversion unit, and the second end is connected to the positive input terminal of the operational amplifier. The first end of the third resistor R9 is connected to the second end of the first resistor R7, the second end is connected to the output terminal of the operational amplifier, and is connected to the first end of the fifth resistor R11. The first end of the fourth resistor R10 is connected to the second end of the second resistor R8, and the second end is connected to the second end of the fifth resistor R11. The first end of the load resistor Rc is connected to the second end of the fifth resistor R11, and the second end is grounded. The DAC receives a digital control signal and outputs a corresponding output voltage so that the adjustable constant current source generates a current corresponding to the target signal based on the output voltage.

[0094] In an embodiment of the present application, the digital control signal is one of N digital control signals, and the N control signals correspond to the N reference resistors one by one. In other words, the digital control signal can be determined according to the selected template reference resistor, and then the corresponding current is generated by the adjustable constant current source 2 based on the determined digital control signal. In the above example of setting two reference resistors of 220Ω and 3.9kΩ, respectively, the output current of the adjustable constant current source 2 can be 10 milliamperes (mA) and 0.6mA, respectively. It should be noted that the current adjustable range of the adjustable constant current source 2 can be between 0mA and 10mA, and by controlling the DAC to input two different digital control signals, the two actual required current values ​​of 10mA and 0.6mA can be obtained.

[0095] Specifically, if Figure 4 The output voltage of the DAC, that is, the voltage at point A, is U A , the voltages at points B and C are U B and U C , and I is the output current value of the adjustable constant current source 2. According to the virtual short and virtual open characteristics of the operational amplifier, formula (1) can be obtained as follows:

[0096]

[0097] Since the resistors R7, R8, R9 and R10 in the circuit are used to form a voltage divider network, their resistance values ​​are completely equal, so by simplifying the above formula (1), we can get formula (2) as follows:

[0098] U A =U B -U C (2)

[0099] Then the calculation formula (3) of the output current I of the constant current source is obtained as follows:

[0100]

[0101] Considering the DAC output voltage range, the resistance value of R11 can be selected to be 200Ω. When the DAC output voltage is 2V, the output current I of the adjustable constant current source 2 is 10mA. When the DAC output voltage is 0.12V, the output current of the adjustable constant current source 2 is 0.6mA.

[0102] Figure 5 It is a flow chart of a method for determining a correction resistance value of a resistor to be corrected provided in an embodiment of the present application. Figure 5 The method shown can be performed by the analog-to-digital conversion unit 3. Figure 5 As shown, the method comprises the following steps:

[0103] In step S501, a target reference voltage is acquired by using a reference signal port pair corresponding to a target reference resistance.

[0104] In step S502, the target input voltage is acquired by using the input signal port pair.

[0105] In step S503, the acquisition code value of the target input voltage is read, and the acquisition code value is used to represent the proportional relationship between the target input voltage and the target reference voltage.

[0106] In step S504, the ratio of the acquired code value to the resolution of the analog-to-digital conversion unit is determined as a first calibration coefficient.

[0107] In step S505, the product of the first calibration coefficient and the resistance value of the target reference resistor is determined as the corrected resistance value of the resistor to be corrected.

[0108] In the embodiment of the present application, the analog-to-digital conversion unit 3 can first use the reference signal port pair corresponding to the target reference resistor to acquire the target reference voltage, and use the input signal port pair to acquire the target input voltage. Next, read the acquisition code value of the target input voltage, and the acquisition code value is used to characterize the proportional relationship between the target input voltage and the target reference voltage. Finally, the ratio of the acquisition code value to the resolution of the analog-to-digital conversion unit is determined as the first calibration coefficient, and the product of the first calibration coefficient and the resistance value of the target reference resistor is determined as the correction resistance value of the resistor to be corrected.

[0109] by Figure 3 Taking the resistor value correction circuit shown in FIG. 1 as an example, if the target reference resistance determined based on the resistance to be corrected is R5, that is, the relay RL5 is turned on, then the target reference voltage acquired by the analog-to-digital conversion unit is the voltage across the target reference resistance R5, which can be expressed as formula (4):

[0110] U REF0 =I×R5 (4)

[0111] At the same time, the input reference voltage collected by the analog-to-digital conversion unit is the voltage across the resistor 5 to be corrected. If the resistor 5 to be corrected is represented by R0, formula (5) can be obtained:

[0112] U AIN =I×R0 (5)

[0113] The acquisition code value of the target input voltage in the analog-to-digital conversion unit can be read. The acquisition code value is used to characterize the proportional relationship between the target input voltage and the target reference voltage. It is represented by Code, and formula (6) can be obtained:

[0114]

[0115] Where K is the number of bits of the analog-to-digital conversion unit 3, 2 K is the resolution of the analog-to-digital conversion unit 3.

[0116] Substituting formula (4) and (5) into formula (6), we can obtain formula (7):

[0117]

[0118] in, is the first calibration coefficient. Simplifying formula (7) can obtain formula (8):

[0119]

[0120] That is to say, the corrected resistance value R0 of the resistor to be corrected can be calculated by multiplying the first calibration coefficient by the resistance value R5 of the target reference resistor.

[0121] By adopting the technical solution of the embodiment of the present application, the proportional relationship between the reference resistor and the resistor to be corrected is determined by utilizing the proportional relationship calculation capability of the analog-to-digital conversion unit itself between the reference voltage and the input voltage, and then the corrected resistance value of the resistor to be corrected is calculated based on the proportional relationship. The implementation is simple and the correction accuracy is high.

[0122] Figure 6 Schematic diagram of a resistance signal source circuit provided by an embodiment of the present application. Figure 6 As shown, the resistance signal source circuit includes an initial resistance signal source circuit 1 and a resistance value correction circuit 2. The initial resistance signal source circuit 1 can be composed of Figure 1 The resistance signal source circuit in the illustrated embodiment comprises a plurality of relays and precision resistors connected in series. Among the relays and precision resistors connected in series, the first end of each relay is connected to a first probe, the second end is connected to the first end of the corresponding precision resistor, and the second end of each precision resistor is connected to a second probe.

[0123] On the other hand, the resistance value correction circuit in the resistance signal source circuit can be composed of Figure 2 or Figure 3 The resistor value correction circuit in the embodiment shown is constructed as follows: the first probe is connected to the first input port of the input signal port of the analog-to-digital conversion unit, and the second probe is connected to the second input port of the input signal port of the analog-to-digital conversion unit.

[0124] That is to say, the high-precision resistance signal source can be composed of 4 relays, 4 precision resistors, communication conversion control circuit and probe. The relay completes the switching selection of 4 kinds of precision resistors. In one example, the Hongfa HFD5 type signal relay with gold-plated contacts can be selected, and the two contacts can be connected in parallel as the selection switch of the precision resistor. The purpose is to minimize the resistance error introduced by the contacts. In practice, the corresponding relay is closed as needed to make the corresponding resistance circuit conductive. The precision resistor can use the RJ711 series high-precision low-temperature drift metal foil precision resistor, with an accuracy of one ten-thousandth and a temperature drift of 5ppm, to ensure the stability and reliability of the resistor. The communication conversion control circuit is used to parse the control commands sent by the terminal device through the communication bus, and control the relay to perform the corresponding closing or disconnecting action. When the relay RL1 is closed and the other three relays are disconnected, the resistor R1 is the resistance signal source. Using the same method, the resistors R2, R3, and R4 can all be used as resistance signal sources. The probe is selected to be a type that can be welded on the printed circuit board to minimize the impedance and interference introduced by the connection between the probe and the switch board.

[0125] The resistor value correction circuit is mainly composed of an adjustable constant current source circuit, an analog-to-digital conversion unit, a precision resistor and a relay. The return path of the constant current source is the relay, the precision resistor R5 or R6, the resistor to be measured R0, and the bias resistor Rb. When the relay RL5 is closed and RL6 is disconnected, the return path is the precision resistor R5. When the relay RL6 is closed and RL5 is disconnected, the return path is the precision resistor R6. The analog-to-digital conversion unit can use a 24-bit ∑-△ type analog-to-digital conversion unit with two reference inputs. The two references are selected through the internal register of the analog-to-digital conversion unit. The acquisition code value of the analog-to-digital conversion unit is represented by Code. The voltage between REF0+ and REF0- is the reference 0 input voltage, represented by U REF0 Indicates that the voltage between AIN+ and AIN- is the input voltage collected by the analog-to-digital conversion unit, and is represented by U AIN Represented. The output current of the constant current source is represented by I. When relay RL5 is closed and RL6 is disconnected, and the constant current source loop path is RL5, R5, R0, and Rc, the reference voltage of the analog-to-digital conversion unit is calculated as shown in formula (4), the input voltage is calculated as shown in formula (5), and the calculation of the acquisition code value, reference, and input voltage of the analog-to-digital conversion unit is as shown in formula (6). Substituting formulas (4) and (5) into formula (6) yields formula (7), and formula (7) is simplified to yield formula (8). It can be seen from formulas (7) and (8) that the output current I of the constant current source will be offset, and resistor R5 serves as the reference for the resistor to be measured. According to the characteristics of the analog-to-digital conversion unit, the reference voltage U of the analog-to-digital conversion unit REF0It needs to be as large as possible to ensure that the resolution of the analog-to-digital conversion unit is higher and the acquisition accuracy is higher. In order to achieve the best test effect, the constant current source output current is required to be as large as possible, and the closer the resistance to be tested and the reference reference resistance are, the better. According to the characteristics that the two resistance values ​​used for calibration in the above-mentioned high-precision thermal resistor detection module are 200Ω and 3.6kΩ, and the two resistance values ​​used for inspection are 100Ω and 3kΩ, in order to improve the test accuracy, two reference resistors R5 and R6 can be selected, where R5 selects a 220Ω precision resistor as the reference reference resistor for 100Ω and 200Ω, and R6 selects a 3.9kΩ precision resistor as the reference reference resistor for 3kΩ and 3.6kΩ. When testing 100Ω and 200Ω, close RL5 and disconnect RL6, select R5 as the reference resistor, select REF0 as the reference reference, and the constant current source outputs 10mA. When testing 3kΩ and 3.6kΩ, close RL6 and disconnect RL5, select R6 as the reference resistor, select REF1 as the reference reference, and the constant current source outputs 0.6mA. By this method, the reference voltage of the analog-to-digital conversion unit is guaranteed to be above 2V during the test, the resolution is as large as possible, and the acquisition accuracy is as high as possible. R5 and R6 are selected as 0.005% precision resistors, and the acquisition error of the analog-to-digital conversion unit can be ignored. According to formula (8), the acquisition accuracy of 100Ω can reach 5mΩ, the acquisition accuracy of 200Ω can reach 10mΩ, the acquisition accuracy of 3kΩ can reach 180mΩ, and the acquisition accuracy of 3.6mΩ can reach 180mΩ.

[0126] Furthermore, the resistance signal source circuit provided in the embodiment of the present application can be used for calibration and inspection of thermistor temperature detection modules. During the production process of thermistor temperature detection modules, the temperature detection module of thermistor to be measured and the high-precision resistance signal source are connected through probes, wherein R1 and R2 are resistors for calibration, and R3 and R4 are resistors for inspection. The terminal device can communicate with the temperature detection module of thermistor to be measured and the high-precision resistance signal source through the communication bus, obtain the acquisition value of the temperature detection module of thermistor to be measured, and control the action of the high-precision resistance signal source relay. The terminal device can store the standard resistance values ​​RS1, RS2, RS3, and RS4 of R1, R2, R3, and R4 locally. The terminal device host controls the relay RL1 to be closed, and the other three are disconnected, and then obtains the resistance value RT1 of R1 collected by the module to be measured, and uses the same method to obtain the resistance value RT2 of R2, and then uses RS1, RS2, RT1, and RT2 to calculate the calibration coefficient through a certain algorithm, and writes the calibration coefficient into the temperature detection module of thermistor to be measured through the communication bus. The terminal device controls relay RL3 to close and the other three to disconnect through the communication bus. Then, the collected value RT3 corrected by the calibration coefficient of the module under test is obtained through the communication bus. RS3 is used as the standard value to calculate the RT3 error and determine whether the accuracy index is met. The same method is used to determine whether the collected value of R4 meets the accuracy index.

[0127] Before each use of the high-precision resistance signal source, the resistance correction circuit can be used to correct the resistance of the high-precision resistance signal source. The terminal device communicates with the resistance correction circuit and the high-precision resistance signal source through the communication bus to obtain the acquisition value of the resistance correction circuit, that is, the information of the resistance to be corrected, and then controls the action of the high-precision resistance signal source relay. The terminal device host first controls the relay RL5 to close and the other three to disconnect, obtain the acquisition value of the resistance correction circuit R5, and update the local acquisition RS1 to the actual acquisition value, and use the same method to update the local acquisition values ​​RS2, RS3, and RS4. This method eliminates the errors introduced by the time changes of the high-precision resistance signal source probe and relay contacts, ensuring the stability and reliability of the signal source accuracy.

[0128] Figure 7 is a flow chart of a method for correcting the resistance value of a resistor provided in an embodiment of the present application. The method can be performed as follows Figure 2 or Figure 3 The resistor value correction circuit in the embodiment shown is implemented. Figure 7 As shown, the method comprises the following steps:

[0129] In step S701 , a resistance to be corrected is determined, and a target reference resistance is selected from a reference resistance selection unit based on the resistance to be corrected.

[0130] In step S702, an adjustable constant current source is used to provide a target signal current for a target reference resistor and a resistor to be corrected.

[0131] In step S703, an analog-to-digital conversion unit is used to acquire a target reference voltage from a target reference resistor and a target input voltage from a resistor to be corrected.

[0132] In step S704 , a first calibration coefficient is determined based on the target reference voltage and the target input voltage.

[0133] In step S705 , a correction resistance value of the resistor to be corrected is determined based on the first calibration coefficient and the resistance value of the target reference resistor.

[0134] In the present application embodiment, when using Figure 2 or Figure 3When the resistance value correction circuit in the illustrated embodiment corrects the resistance value, the resistance to be corrected can be first determined, and the target reference resistance can be selected from the reference resistance selection unit based on the resistance to be corrected. Then, an adjustable constant current source is used to provide a target signal current for the target reference resistance and the resistance to be corrected. Next, an analog-to-digital conversion unit is used to collect a target reference voltage from the target reference resistance, and a target input voltage from the resistance to be corrected, and a first calibration coefficient is determined based on the target reference voltage and the target input voltage. Finally, based on the first calibration coefficient and the resistance value of the target reference resistance, the corrected resistance value of the resistance to be corrected is determined.

[0135] Further, determining the first calibration coefficient based on the target reference voltage and the target input voltage can be implemented in the following manner: reading the acquisition code value of the target input voltage, the acquisition code value is used to characterize the proportional relationship between the target input voltage and the target reference voltage; determining the ratio of the acquisition code value to the resolution of the analog-to-digital conversion unit as the first calibration coefficient. Determining the corrected resistance value of the resistor to be corrected based on the first calibration coefficient and the resistance value of the target reference resistor can be implemented in the following manner: determining the product of the first calibration coefficient and the resistance value of the target reference resistor as the corrected resistance value of the resistor to be corrected.

[0136] Figure 8 FIG. 1 is a flow chart of a method for calibrating a thermal resistor temperature detection module provided in an embodiment of the present application. Figure 8 As shown, the method comprises the following steps:

[0137] In step S801, a high-precision resistance signal source is provided to a thermal resistance temperature detection module through a probe.

[0138] In step S802, the high-precision resistance signal source is corrected using a resistance value correction circuit to obtain a corrected high-precision resistance signal source.

[0139] The resistance value correction circuit can be as follows: Figure 2 or Figure 3 The embodiment shown provides a resistor value correction circuit.

[0140] In step S803, a first collected resistance value of the thermal resistor temperature detection module is collected.

[0141] In step S804, a second calibration coefficient is calculated based on the first collected resistance value and the resistance value of the corrected high-precision resistance signal source.

[0142] In step S805, the thermal resistance temperature detection module is calibrated using the second calibration coefficient.

[0143] In the embodiment of the present application, when calibrating the thermal resistor temperature detection module, a high-precision resistance signal source can be first provided to the thermal resistor temperature detection module through a probe. Then, the high-precision resistance signal source is corrected using a resistance value correction circuit to obtain a corrected high-precision resistance signal source, wherein the resistance value correction circuit can be as follows: Figure 2 or Figure 3 The resistor value correction circuit provided in the embodiment shown. Next, the first collected resistance value of the thermal resistor temperature detection module is collected, and the second calibration coefficient is calculated based on the first collected resistance value and the resistance value of the corrected high-precision resistance signal source. Finally, the thermal resistor temperature detection module is calibrated using the second calibration coefficient.

[0144] Fig. 9 FIG. 1 is a flow chart of a method for testing a thermal resistor temperature detection module provided in an embodiment of the present application. Fig. 9 As shown, the method comprises the following steps:

[0145] In step S901, a high-precision resistance signal source is provided to a thermal resistance temperature detection module through a probe.

[0146] In step S902, the high-precision resistance signal source is corrected using a resistance value correction circuit to obtain a corrected high-precision resistance signal source.

[0147] The resistance value correction circuit can be as follows: Figure 2 or Figure 3 The embodiment shown provides a resistor value correction circuit.

[0148] In step S903, a second collected resistance value of the thermal resistor temperature detection module is collected.

[0149] In step S904, the second collected resistance value is compared with the resistance value of the corrected high-precision resistance signal source, and in response to the comparison result being less than or equal to a preset threshold, it is determined that the thermal resistance temperature detection module has passed the inspection.

[0150] In the embodiment of the present application, when testing the thermal resistor temperature detection module, a high-precision resistance signal source can be first provided to the thermal resistor temperature detection module through a probe. Then, the high-precision resistance signal source is corrected using a resistance value correction circuit to obtain a corrected high-precision resistance signal source, wherein the resistance value correction circuit can be as follows: Figure 2 or Figure 3 The resistor value correction circuit provided in the embodiment shown. Next, the second collected resistance value of the thermal resistor temperature detection module is collected. Finally, the second collected resistance value is compared with the resistance value of the corrected high-precision resistance signal source, and in response to the comparison result being less than or equal to the preset threshold, it is determined that the thermal resistor temperature detection module has passed the inspection.

[0151] By adopting the technical solution of the embodiment of the present application, a high-precision resistance signal source can be provided for the scene where different resistances used for calibration and inspection in production need to be automatically switched. The resistance signal source provided by the embodiment of the present application uses two contacts of the electrical appliance in parallel as a switching switch for precision resistance switching, which reduces the error introduced by the contact impedance compared to a single contact; the precision resistor uses the RJ711 series metal foil precision resistor, which has the characteristics of high precision and low temperature drift, ensuring that the resistance signal source is stable and reliable; the probe is directly welded on the printed circuit board, eliminating the wire impedance and noise when the probe and the printed circuit board are wound and connected; the standard high-precision thermal resistor detection module is used as a software correction calibration source for the high-precision resistance signal source, which can dynamically correct the standard resistance value of the high-precision resistance signal source; the resistance value correction circuit can be implemented as a standard high-precision thermal resistor detection module, which uses the voltage generated by the constant current source current on the reference high-precision resistor as the reference reference voltage, eliminating the influence of the constant current source on the test result and improving the test accuracy; the standard high-precision thermal resistor detection module uses an adjustable constant current source and a dynamically switchable high-precision resistance reference benchmark to improve the test accuracy.

[0152] The resistance signal source provided in the embodiment of the present application has high precision, high stability, high production efficiency, and software correction. Through the method of software correction, the error of the resistance signal source changing over time is eliminated, and the accuracy of the resistance signal source is guaranteed to be within 0.005%. Compared with the manual installation resistance solution and the ordinary relay switching solution in the prior art, the accuracy and efficiency are greatly improved.

[0153] All the above optional technical solutions can be arbitrarily combined to form optional embodiments of the present application, which will not be described one by one here.

[0154] Fig.10 Schematic diagram of an electronic device provided in an embodiment of the present application. Fig.10 As shown, the electronic device 10 of this embodiment includes: a processor 1001, a memory 1002, and a computer program 1003 stored in the memory 1002 and executable on the processor 1001. When the processor 1001 executes the computer program 1003, the steps in the above-mentioned method embodiments are implemented. Alternatively, when the processor 1001 executes the computer program 1003, the functions of the modules / units in the above-mentioned device embodiments are implemented.

[0155] The electronic device 10 may be a desktop computer, a notebook, a PDA, a cloud server, or other electronic device. The electronic device 10 may include, but is not limited to, a processor 1001 and a memory 1002. Those skilled in the art will appreciate that Fig.10 The electronic device 10 is merely an example and does not limit the electronic device 10 . The electronic device 10 may include more or fewer components than shown in the figure, or different components.

[0156] Processor 1001 can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0157] The memory 1002 may be an internal storage unit of the electronic device 10, for example, a hard disk or memory of the electronic device 10. The memory 1002 may also be an external storage device of the electronic device 10, for example, a plug-in hard disk, a smart media card (SMC), a secure digital (SD) card, a flash card (FlashCard), etc. equipped on the electronic device 10. The memory 1002 may also include both an internal storage unit of the electronic device 10 and an external storage device. The memory 1002 is used to store computer programs and other programs and data required by the electronic device.

[0158] Those skilled in the art can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. In actual applications, the above-mentioned functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units.

[0159] If the integrated module / unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned various method embodiments when executed by the processor. The computer program may include computer program code, which may be in source code form, object code form, executable file or some intermediate form. Computer-readable media may include: any entity or device capable of carrying computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium, etc.

[0160] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A resistor value correction circuit, characterized in that: include: Reference resistor selection unit, adjustable constant current source and analog-to-digital conversion unit; The reference resistance selection unit selects a target reference resistance based on the resistance to be corrected of the resistance value correction circuit; The adjustable constant current source provides a target signal current for the target reference resistor and the resistor to be corrected; The analog-to-digital conversion unit is used to determine a target reference voltage based on the target signal current and the target reference resistance, determine a target input voltage based on the target signal current and the resistance to be corrected, and determine a correction resistance value of the resistance to be corrected based on the target reference voltage and the target input voltage.

2. The circuit according to claim 1, characterized in that The analog-to-digital conversion unit includes N pairs of reference signal ports and a pair of input signal ports, where N is a positive integer greater than 1; Each pair of reference signal ports includes a first reference port and a second reference port, wherein the first reference port is used to collect a positive reference signal, and the second reference port is used to collect a negative reference signal; The input signal port includes a first input port and a second input port, the first input port is used to collect a positive input signal, and the second input port is used to collect a negative input signal.

3. The circuit according to claim 2, characterized in that The reference resistor selection unit is composed of N relays and N reference resistors, the N relays correspond to the N reference resistors one-to-one, and the N pairs of reference signal ports also correspond to the N reference resistors one-to-one; Among the N relays, a first end of each relay is connected to a first end of a corresponding reference resistor in a double-contact parallel manner, and a second end is connected to an output end of the adjustable constant current source; Among the N reference resistors, the first end of each reference resistor is also connected to the first reference port of the corresponding reference signal port pair, and the second end is connected to the second reference port of the corresponding reference signal port pair and connected to the first end of the resistor to be corrected.

4. The circuit according to claim 2, characterized in that The reference resistor selection unit is composed of two relays and N reference resistors, wherein the first relay is connected in series with N / two reference resistors, the second relay is connected in series with the remaining N / two reference resistors, and the N pairs of reference signal ports correspond one to one with the N reference resistors; In the two relays, a first end of each relay is connected to a first end of a reference resistor in a double-contact parallel manner, and a second end is connected to an output end of the adjustable constant current source; Among the N / two reference resistors connected in series, the first section of each reference resistor is connected to the first reference port of the corresponding reference signal port pair, and the second end is connected to the second reference port of the corresponding reference signal port pair, and the first end of the first reference resistor is also connected to the corresponding relay, and the second end of the last reference resistor is also connected to the first end of the resistor to be corrected.

5. The circuit according to any one of claims 2 to 4, characterized in that The adjustable constant current source comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a load resistor, an operational amplifier and a digital-to-analog conversion unit; A first end of the first resistor is grounded, and a second end is connected to the negative input terminal of the operational amplifier; A first end of the second resistor is connected to the output end of the digital-to-analog conversion unit, and a second end is connected to the positive input end of the operational amplifier; The first end of the third resistor is connected to the second end of the first resistor, the second end is connected to the output end of the operational amplifier, and is connected to the first end of the fifth resistor; The first end of the fourth resistor is connected to the second end of the second resistor, and the second end of the fourth resistor is connected to the second end of the fifth resistor; The first end of the load resistor is connected to the second end of the fifth resistor, and the second end is grounded; The digital-to-analog conversion unit receives a digital control signal and outputs a corresponding output voltage, so that the adjustable constant current source generates a current corresponding to the target signal based on the output voltage; The digital control signal is one of N digital control signals, and the N control signals correspond one-to-one to the N reference resistors.

6. The circuit according to claim 1, characterized in that The resistance value correction circuit also includes a bias resistor; The first end of the bias resistor is connected to the resistor to be corrected, and the second end is grounded.

7. A resistance signal source circuit, characterized in that: The resistance signal source circuit includes an initial resistance signal source circuit and a resistance value correction circuit; The initial resistance signal source circuit includes a plurality of relays and precision resistors connected in series; Among the relays and precision resistors connected in series, the first end of each relay is connected to the first probe, the second end is connected to the first end of the corresponding precision resistor, and the second end of each precision resistor is connected to the second probe; The resistance value correction circuit is the resistance value correction circuit as described in any one of claims 1 to 6, the first probe is connected to the first input port of the input signal port of the analog-to-digital conversion unit, and the second probe is connected to the second input port of the input signal port of the analog-to-digital conversion unit.

8. A method for correcting the resistance value of a resistor, characterized in that: The method is performed by the resistor value correction circuit according to any one of claims 1 to 7, and the method comprises: Determine a resistance to be corrected, and select a target reference resistance from the reference resistance selection unit based on the resistance to be corrected; Using the adjustable constant current source to provide a target signal current for the target reference resistor and the resistor to be corrected; Using the analog-to-digital conversion unit to respectively acquire a target reference voltage from the target reference resistor and acquire a target input voltage from the resistor to be corrected; determining a first calibration coefficient based on the target reference voltage and the target input voltage; Based on the first calibration coefficient and the resistance value of the target reference resistor, a correction resistance value of the resistor to be corrected is determined.

9. The method according to claim 8, characterized in that The determining a first calibration coefficient based on the target reference voltage and the target input voltage comprises: Reading an acquisition code value of the target input voltage, wherein the acquisition code value is used to characterize a proportional relationship between the target input voltage and a target reference voltage; Determine a ratio of the acquisition code value to a resolution of the analog-to-digital conversion unit as the first calibration coefficient; The step of determining the corrected resistance value of the resistor to be corrected based on the first calibration coefficient and the resistance value of the target reference resistor comprises: The product of the first calibration coefficient and the resistance value of the target reference resistor is determined as the corrected resistance value of the resistor to be corrected.

10. A method for calibrating a thermal resistance temperature detection module, characterized in that: include: Providing a high-precision resistance signal source for the thermal resistance temperature detection module through a probe; Using the resistance value correction circuit as described in any one of claims 1 to 6 to correct the high-precision resistance signal source, to obtain a corrected high-precision resistance signal source; Collecting a first collected resistance value of the thermal resistance temperature detection module; Calculating a second calibration coefficient based on the first collected resistance value and the resistance value of the corrected high-precision resistance signal source; The thermal resistance temperature detection module is calibrated using the second calibration coefficient.

11. A method for testing a thermal resistance temperature detection module, characterized in that: include: Providing a high-precision resistance signal source for the thermal resistance temperature detection module through a probe; Using the resistance value correction circuit as described in any one of claims 1 to 6 to correct the high-precision resistance signal source, to obtain a corrected high-precision resistance signal source; Collecting a second collected resistance value of the thermal resistance temperature detection module; The second collected resistance value is compared with the resistance value of the corrected high-precision resistance signal source, and in response to the comparison result being less than or equal to a preset threshold, it is determined that the thermal resistance temperature detection module has passed the inspection.

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