Voltage reference source calibration method and self-calibration type voltage reference source

Abstract

The invention belongs to the technical field of electronics, and particularly relates to a voltage reference source calibration method and a self-calibration type voltage reference source. In the operation process of the voltage reference source, calibration is triggered regularly or when the working temperature variation of the calibration reference in the voltage reference source is larger than a temperature variation threshold value; the calibration process comprises the steps that the output voltage of the calibration reference is detected, if the output voltage of the calibration reference changes, the error compensation voltage is determined according to the current working temperature of the calibration reference, the output voltage of the calibration reference is adjusted based on the error compensation voltage, and the adjusted output voltage of the calibration reference is detected. If the output voltage of the calibration reference does not meet the reference voltage output requirement, adjustment continues until the output voltage of the calibration reference meets the reference voltage output requirement, output deviation is corrected online through closed-loop control, the compensation precision is high, meanwhile, internal self-calibration is directly achieved without depending on an external calibration tool, and the maintenance cost is reduced.

Description

Technical Field

[0001] This invention belongs to the field of electronic technology, specifically relating to a voltage reference source calibration method and a self-calibrating voltage reference source. Background Technology

[0002] In modern electronic systems, high-precision voltage references are core components ensuring the accuracy of signal links. Their precise and stable output reference voltages are widely used in circuit systems across precision measurement, industrial control, communication equipment, and medical instruments. However, environmental disturbances significantly limit the long-term stability of voltage references. Factors such as temperature drift, power supply noise, and mechanical vibration can cause cumulative deviations in the output voltage. Especially in complex industrial scenarios or wide-temperature applications, errors can reach ±0.1% or more, far exceeding the sub-millivolt accuracy requirements of high-precision voltage references. Therefore, calibration of the reference voltage source is necessary to achieve the expected voltage output accuracy.

[0003] Existing solutions typically employ static calibration, such as offline calibration or periodic manual calibration. Static calibration requires shutting down the system containing the voltage reference source, relying on expensive precision instruments and professional personnel. It cannot achieve real-time compensation, and the long system downtime significantly increases maintenance costs. To reduce calibration costs, Chinese Patent CN217133620U discloses a voltage reference source circuit, device, and vehicle. This invention connects a second resistor and a thermistor with complementary characteristics to the adjustable reference source in parallel at the adjustable reference source. When the ambient temperature varies within the range of -40°C to +25°C, as the ambient temperature decreases, the voltage at the reference electrode of the adjustable reference source decreases, and the resistance of the thermistor increases. This, in turn, increases the resistance of the parallel combination of the thermistor and the second resistor. The increased resistance of the parallel combination of the thermistor and the second resistor leads to an increased voltage drop between the reference electrode and the cathode of the adjustable reference source. This reduces the fluctuations in the reference voltage output by the adjustable reference source due to changes in ambient temperature, ensuring the stability of the reference voltage output by the voltage reference source circuit. This method uses a thermistor to roughly compensate for the output voltage accuracy of the voltage reference source under temperature changes. However, the compensation accuracy is low, the output voltage deviation after compensation is still large, and it lacks a dynamic closed-loop feedback mechanism, making it unsuitable for voltage reference source calibration in high-precision scenarios. Summary of the Invention

[0004] The purpose of this invention is to provide a voltage reference source calibration method and a self-calibrating voltage reference source to solve the problem that the output voltage deviation of existing voltage reference sources is still large after calibration.

[0005] To address the aforementioned technical problems, this invention provides a voltage reference source calibration method, comprising: periodically triggering calibration during the operation of the voltage reference source, or triggering calibration when the change in the operating temperature of the calibration reference in the voltage reference source exceeds a temperature change threshold; the calibration process includes: detecting the output voltage of the calibration reference; if the output voltage of the calibration reference changes, determining an error compensation voltage based on the current operating temperature of the calibration reference; adjusting the output voltage of the calibration reference based on the error compensation voltage; detecting the adjusted output voltage of the calibration reference; if the output voltage of the calibration reference does not meet the reference voltage output requirement, continuing adjustment until the output voltage of the calibration reference meets the reference voltage output requirement, then using it as the reference voltage output; and updating the error compensation voltage corresponding to meeting the reference voltage output requirement to the error compensation voltage at that operating temperature; if the requirement is met, then directly using it as the reference voltage output.

[0006] Furthermore, meeting the reference voltage output requirement means that the error between the output voltage of the calibration reference and the output voltage of the main reference is less than or equal to the zero-point error; the main reference is used to provide a reference voltage reference for the voltage reference source; the zero-point error refers to the value at which the error between the output voltage of the calibration reference and the output voltage of the main reference meets the accuracy requirements of the voltage reference source after the voltage reference source is initialized and calibrated during the production stage.

[0007] Furthermore, the method for determining if the output voltage of the calibration reference has changed is as follows: the output voltage of the calibration reference and the output voltage of the main reference are collected. When the error between the output voltage of the calibration reference and the output voltage of the main reference is greater than the zero-point error, it is determined that the output voltage of the calibration reference has changed.

[0008] Furthermore, the method for determining the error compensation voltage is as follows: based on the current operating temperature of the calibration reference, find the corresponding error compensation voltage at each pre-calibrated operating temperature. The calibration process is as follows: test the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, determine the corresponding compensation coefficient based on the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, and calculate the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration in the production stage.

[0009] Furthermore, when adjusting the output voltage of the calibration reference based on the error compensation voltage, the output voltage of the calibration reference is adjusted in a step-by-step manner.

[0010] The beneficial effects of the above technical solution are as follows: This invention is a pioneering invention. During the operation of the voltage reference source, the operating temperature is detected, and online self-calibration is performed periodically, or when the change in operating temperature exceeds the temperature change threshold, online self-calibration is performed. When the output voltage changes, the error compensation voltage that needs to be calibrated is determined based on the current real-time operating temperature. The calibration reference is adjusted based on the error compensation voltage and then detected again. If the reference voltage output requirement is not met, the adjustment continues until the output voltage of the calibration reference meets the reference voltage output requirement and is used as the reference voltage output. The error compensation voltage at this operating temperature is updated for accurate adjustment next time. This invention can dynamically offset the voltage drift caused by ambient temperature, correct the output deviation online through closed-loop control, and has high compensation accuracy. At the same time, it can directly achieve internal self-calibration without relying on external calibration tools, reducing maintenance costs.

[0011] To address the aforementioned technical problems, this invention also provides a self-calibrating voltage reference source, comprising a calibration reference, a temperature detection module, a feedback circuit module, and a self-calibration control module. The temperature detection module is used to acquire the operating temperature of the calibration reference in the voltage reference source. The self-calibration control module is used to periodically trigger calibration or to trigger calibration when the change in the operating temperature of the calibration reference exceeds a temperature change threshold. The calibration process includes: using the feedback circuit module to detect the output voltage of the calibration reference; if the output voltage of the calibration reference changes, the self-calibration control module determines an error compensation voltage based on the current operating temperature of the calibration reference; adjusting the output voltage of the calibration reference based on the error compensation voltage; using the feedback circuit module to detect the adjusted output voltage of the calibration reference; if the output voltage of the calibration reference does not meet the reference voltage output requirement, adjustment continues until the output voltage of the calibration reference meets the reference voltage output requirement, and then it is used as the reference voltage output. The error compensation voltage corresponding to meeting the reference voltage output requirement is updated to the error compensation voltage at that operating temperature; if it meets the requirement, it is directly used as the reference voltage output.

[0012] Furthermore, it also includes a primary reference, which is used to provide a reference voltage for the voltage reference source; the feedback circuit module is also connected to the primary reference and is used to obtain the error between the output voltage of the calibration reference and the output voltage of the primary reference; when the error between the output voltage of the calibration reference and the output voltage of the primary reference is less than or equal to the zero-point error, it is determined that the output voltage of the calibration reference meets the reference voltage output requirements; the zero-point error refers to the value at which the error between the output voltage of the calibration reference and the output voltage of the primary reference meets the accuracy requirements of the voltage reference source after the voltage reference source is initialized and calibrated during the production stage.

[0013] Furthermore, the method for determining if the output voltage of the calibration reference has changed is as follows: when the error between the output voltage of the calibration reference obtained by the feedback circuit module and the output voltage of the main reference is greater than the zero-point error, it is determined that the output voltage of the calibration reference has changed.

[0014] Furthermore, the self-calibration control module determines the error compensation voltage based on the current operating temperature of the calibration reference by finding the corresponding error compensation voltage at each pre-calibrated operating temperature. The calibration process involves testing the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, determining the corresponding compensation coefficient based on the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, and calculating the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration during the production stage.

[0015] Furthermore, the self-calibration control module stores the zero-point error and the error compensation voltage corresponding to each pre-calibrated operating temperature, and updates the error compensation voltage when the reference voltage output requirement is met at each operating temperature.

[0016] The beneficial effects of the above technical solution are as follows: This invention is a pioneering invention. During the operation of the voltage reference source, the operating temperature is detected, and online self-calibration is performed periodically, or when the change in operating temperature exceeds the temperature change threshold, online self-calibration is performed. When the output voltage changes, the error compensation voltage that needs to be calibrated is determined based on the current real-time operating temperature. The calibration reference is adjusted based on the error compensation voltage and then detected again. If the reference voltage output requirement is not met, the adjustment continues until the output voltage of the calibration reference meets the reference voltage output requirement and is used as the reference voltage output. The error compensation voltage at this operating temperature is updated for accurate adjustment next time. This invention can dynamically offset the voltage drift caused by ambient temperature, correct the output deviation online through closed-loop control, and has high compensation accuracy. At the same time, it can directly achieve internal self-calibration without relying on external calibration tools, reducing maintenance costs. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the self-calibrating voltage reference system according to an embodiment of the present invention. Figure 2 This is an initialization calibration flowchart of an embodiment of the self-calibrating voltage reference source system of the present invention; Figure 3 This is a flowchart illustrating the self-calibration process during operation of the self-calibrating voltage reference source system of the present invention. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the present invention clearer, the specific embodiments of the present invention will be further described below with reference to the accompanying drawings.

[0019] This invention combines online monitoring and closed-loop control of temperature detection and calibration reference output voltage to dynamically offset voltage drift caused by ambient temperature, thereby improving the accuracy of voltage reference source calibration.

[0020] Self-calibrating voltage reference source implementation method The present invention provides a self-calibrating voltage reference source for realizing online self-calibration of a high-precision voltage reference source.

[0021] In one embodiment, the self-calibrating voltage reference source includes a calibration reference, a temperature detection module, a feedback circuit module, a self-calibration control module, and an output buffer circuit module.

[0022] The calibration reference, controlled by the self-calibration control module, can output different voltage values ​​to provide a reference voltage for external loads. It typically consists of a high-precision voltage output digital-to-analog converter (DAC) and its associated circuitry, connected to the self-calibration module, which can control its output voltage.

[0023] The temperature detection module monitors the operating temperature of the calibration reference in the voltage reference source in real time. It typically consists of a high-precision temperature sensor and its associated circuitry, and is connected to the self-calibration module to provide the self-calibration control module with the real-time operating temperature of the self-calibrating voltage reference source.

[0024] The feedback circuit module is used to detect the output voltage of the calibration reference. It typically consists of a high-precision analog-to-digital converter (ADC) and its associated circuitry, and is connected to the self-calibration control module.

[0025] The self-calibration control module includes a controller, a memory, and its auxiliary circuitry. It adjusts the output voltage of the calibration reference based on the parameters stored in the built-in memory, achieving self-calibration of the voltage reference. The controller can be a DSP or FPGA, and the memory can be an EEPROM. The DSP or FPGA adjusts the output voltage of the calibration reference according to the parameters stored in the built-in memory. During operation, it adjusts the calibration voltage output based on real-time temperature and changes in the calibration reference output voltage, achieving self-calibration. The memory parameters include the zero-point error and the error compensation voltages corresponding to each pre-calibrated operating temperature. The memory also updates the error compensation voltage and offset used to ensure the output voltage of the calibration reference meets the reference voltage output requirements. The zero-point error refers to the value at which the error between the output voltage of the calibration reference and the output voltage of the main reference meets the accuracy requirements of the voltage reference source after initial calibration during the production stage.

[0026] The output buffer circuit module is a voltage shaping circuit after the calibration reference stage, ensuring a stable output calibrated voltage.

[0027] In another embodiment, such as Figure 1 As shown, a self-calibrating voltage reference source also includes a main reference, which provides a reference voltage for the entire self-calibrating voltage reference source. It typically consists of a voltage reference chip or a Zener diode and its associated circuitry. A buffer circuit can be added to the self-calibrating voltage reference source to isolate the main reference from the load, preventing load fluctuations from affecting the reference stability. Feedback circuit module ( Figure 1 The error amplification and feedback circuit module in the system connects the calibration reference and the main reference. It is used to collect the output voltage of the calibration reference and the output voltage of the main reference, and to obtain the error between the output voltage of the calibration reference and the output voltage of the main reference. It can also further amplify the error to improve the detection accuracy.

[0028] Since the noise and stability of core components directly affect the absolute accuracy of a programmable voltage reference, the reference chip or core components such as Zener diodes, operational amplifiers, ADCs, DACs, DSPs, or FPGAs in a self-calibrating voltage reference source should be selected with low temperature drift coefficients and low voltage noise. Aging screening of the selected components can also be performed to achieve high stable voltage output and ensure the output accuracy of the self-calibrating voltage reference source system.

[0029] The self-calibration process of a self-calibrating voltage reference source consists of two stages: initial calibration (first calibration), which is performed during the production stage; and runtime self-calibration (dynamic calibration), which is triggered periodically during the operation of the voltage reference source or when the operating temperature change of the reference exceeds a temperature change threshold. These are explained in detail below.

[0030] 1. Initialize calibration.

[0031] The initial calibration process is as follows: Figure 2 As shown, it includes: 1) Disconnect the load to ensure all circuit connections are normal, activate the master reference and wait for warm-up.

[0032] 2) Set the output voltage of the calibration reference: The controller of the self-calibration control module controls the output voltage of the calibration reference DAC to match the output voltage of the main reference.

[0033] 3) Acquire raw data: Use the feedback circuit module ADC to continuously sample the output voltage of the main reference and the output voltage of the calibration reference, and calculate the average value of the output voltage of the main reference and the average value of the output voltage of the calibration reference.

[0034] 4) Calculate the initial error. The initial error is the offset between the average value of the output voltage of the main reference and the average value of the output voltage of the calibration reference. If the initial error exceeds the threshold (e.g., ±1mV), proceed to parameter adjustment.

[0035] 5) Parameter adjustment: The output voltage of the calibration reference DAC is adjusted by the PID algorithm of the self-calibration control module, so that the error between the output voltage of the calibration reference and the output voltage of the main reference is reduced to the zero-point error, that is, close to 0, to achieve gain and offset calibration. At the same time, the zero-point error is recorded and stored in EEPROM.

[0036] 2. Runtime self-calibration.

[0037] The runtime self-calibration process is as follows: Figure 3 As shown, it includes: 1) Trigger self-calibration.

[0038] During the operation of the voltage reference source, calibration is triggered periodically or when the operating temperature change of the reference in the voltage reference source exceeds a temperature change threshold. The triggering period can be customized, for example, triggering self-calibration every 10 minutes.

[0039] The operating temperature of the calibration reference is collected in real time. When the change in operating temperature is greater than the temperature change threshold, self-calibration is triggered. The temperature change threshold can be set according to the actual situation, for example, it can be set to 0.5℃. When the change in operating temperature ΔT>0.5℃, self-calibration is triggered.

[0040] 2) Determine whether the output voltage of the calibration reference has changed, and perform dynamic error compensation if it has changed.

[0041] The method for determining if the output voltage of the calibration reference has changed is as follows: The feedback circuit module acquires the error between the output voltage of the calibration reference and the output voltage of the main reference. When the error between the output voltage of the calibration reference and the output voltage of the main reference is greater than the zero-point error, it is determined that the output voltage of the calibration reference has changed. Alternatively, the output voltage of the calibration reference is acquired, and when the output voltage of the calibration reference is not equal to the output voltage of the calibration reference determined after initial calibration, it is determined that the output voltage of the calibration reference has changed.

[0042] If the output voltage of the calibration reference changes, the self-calibration control module determines the error compensation voltage based on the current operating temperature of the calibration reference. Based on this error compensation voltage, the output voltage of the calibration reference is adjusted. The feedback circuit module detects the adjusted output voltage of the calibration reference. If the output voltage does not meet the reference voltage output requirement, adjustment continues until the output voltage meets the requirement, at which point it is used as the reference voltage output. The error compensation voltage corresponding to when the requirement is met is then updated to the error compensation voltage at that operating temperature. If the requirement is met, it is directly used as the reference voltage output. During adjustment, the output voltage of the calibration reference DAC is adjusted using a PID algorithm based on the aging characteristics of the voltage reference source device until the output voltage meets the reference voltage output requirement, at which point it is used as the reference voltage output.

[0043] The self-calibration control module determines the error compensation voltage based on the current operating temperature of the calibration reference by: finding the corresponding error compensation voltage at each pre-calibrated operating temperature based on the current operating temperature of the calibration reference; the calibration process involves: testing the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature; determining the corresponding compensation coefficient based on the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature; and calculating the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration during the production stage.

[0044] Meeting the reference voltage output requirement means that the error between the output voltage of the calibration reference and the output voltage of the main reference is less than or equal to the zero-point error, or that the output voltage of the calibration reference is equal to or the output voltage of the calibration reference determined after initial calibration is less than the error threshold range.

[0045] Temperature drift compensation can be achieved by directly adjusting the output voltage of the calibration reference based on the error compensation voltage. Preferably, the output voltage of the calibration reference is adjusted gradually (e.g., incrementally). For example, the DAC output can be gradually corrected using Kalman filtering to avoid sudden changes in the output voltage data.

[0046] 3) Parameter saving.

[0047] The error compensation voltage at the operating temperature is compared with the pre-calibrated error compensation voltage value in the EEPROM. If they differ, the error compensation voltage and offset at the corresponding operating temperature in the EEPROM are updated. The offset refers to the error between the output voltage of the calibration reference and the output voltage of the main reference at the corresponding operating temperature. Since voltage reference source devices have aging characteristics, if the factory calibration values ​​are used continuously, their electronic characteristics will change with use. Therefore, this invention continuously adjusts the parameters and saves the corresponding error compensation voltage and offset during actual operation of the voltage reference source, adapting to parameter changes caused by the aging of the voltage reference source device and preventing the original parameters from becoming inapplicable when the device characteristics change.

[0048] Method Implementation The present invention provides a voltage reference source calibration method, which achieves self-calibration based on the self-calibrating voltage reference source described in the embodiment of the self-calibrating voltage reference source.

[0049] The self-calibration process consists of two stages: initial calibration (first calibration), which is performed during the production phase; and runtime self-calibration (dynamic calibration), which occurs during the operation of the voltage reference source. These are explained in detail below.

[0050] Initial calibration includes: disconnecting the load to ensure all circuit connections are normal, activating the master reference and waiting for warm-up. Setting the calibration reference output voltage: controlling the calibration reference DAC output to match the master reference output voltage. Acquiring raw data: continuously sampling the output voltages of the master reference and the calibration reference, simultaneously calculating the average values ​​of their output voltages. Calculating the initial error: the difference between the average values ​​of the master reference and the calibration reference output voltages. If the initial error exceeds a threshold (e.g., ±1mV), parameter adjustment begins. Performing parameter adjustment: adjusting the calibration reference DAC output voltage using a PID algorithm to reduce the error between the calibration reference and the master reference output voltage to zero-point error, achieving gain and offset calibration. Simultaneously, the zero-point error is recorded and stored in EEPROM.

[0051] Runtime self-calibration. Includes: S1: Trigger self-calibration.

[0052] During the operation of the voltage reference source, calibration is triggered periodically or when the operating temperature change of the calibration reference exceeds the temperature change threshold.

[0053] S2: Determine whether the output voltage of the calibration reference has changed, and perform dynamic error compensation if it has changed.

[0054] The method for determining if the output voltage of the calibration reference has changed is as follows: The error between the output voltage of the calibration reference and the output voltage of the main reference is considered a change if the error is greater than the zero-point error. Alternatively, the output voltage of the calibration reference can be collected; if the output voltage of the calibration reference is not equal to the output voltage determined after initial calibration, the change is also considered a change.

[0055] The error compensation voltage is determined as follows: It is calculated based on the current operating temperature of the voltage reference source and a pre-stored model. The pre-stored model refers to the error compensation voltage model corresponding to each operating temperature, which has been calibrated in advance. That is, the error compensation voltage corresponding to each pre-calibrated operating temperature is found. The calibration process involves: testing the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature; determining the corresponding compensation coefficient based on the deviation between the output voltage of the calibration reference and the main reference at each operating temperature; and calculating the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration during the production phase.

[0056] Meeting the reference voltage output requirement means that the error between the output voltage of the calibration reference and the output voltage of the main reference is less than or equal to the zero-point error, or that the output voltage of the calibration reference is equal to or the output voltage of the calibration reference determined after initial calibration is less than the error threshold range.

[0057] Temperature drift compensation can be achieved by directly adjusting the output voltage of the calibration reference based on the error compensation voltage. Preferably, the output voltage of the calibration reference is adjusted stepwise based on the error compensation voltage. For example, the DAC output can be gradually corrected through Kalman filtering to avoid sudden changes in the output voltage data.

[0058] This invention continuously corrects errors based on the error compensation voltage at the current operating temperature when the output voltage of the voltage reference source changes, which is superior to traditional static calibration. It combines a temperature sensor and a PID algorithm model to dynamically offset voltage drift caused by ambient temperature. Compared with the manual calibration mode of traditional solutions, this invention directly achieves internal self-calibration, and realizes full closed-loop feedback compensation from ADC sampling to DAC compensation (response time <1ms), without relying on external calibration tools. This results in higher compensation accuracy and reduced maintenance costs.

Claims

1. A voltage reference source calibration method, characterized in that, include: During the operation of the voltage reference source, calibration is triggered periodically or when the operating temperature change of the reference in the voltage reference source exceeds the temperature change threshold. The calibration process includes: detecting the output voltage of the calibration reference; if the output voltage of the calibration reference changes, determining the error compensation voltage based on the current operating temperature of the calibration reference; adjusting the output voltage of the calibration reference based on the error compensation voltage; detecting the adjusted output voltage of the calibration reference; if the output voltage of the calibration reference does not meet the reference voltage output requirement, continuing the adjustment until the output voltage of the calibration reference meets the reference voltage output requirement, then using it as the reference voltage output, and updating the error compensation voltage corresponding to when the reference voltage output requirement is met to the error compensation voltage at that operating temperature; if it meets the requirement, then directly using it as the reference voltage output.

2. The voltage reference source calibration method according to claim 1, characterized in that, Meeting the reference voltage output requirement means that the error between the output voltage of the calibration reference and the output voltage of the main reference is less than or equal to zero-point error; the main reference is used to provide a reference voltage for the voltage reference source. Zero-point error refers to the error between the output voltage of the calibration reference and the output voltage of the main reference after the voltage reference source is initialized and calibrated during the production stage, which meets the accuracy requirements of the voltage reference source.

3. The voltage reference source calibration method according to claim 2, characterized in that, The method for determining if the output voltage of the calibration reference has changed is as follows: collect the output voltage of the calibration reference and the output voltage of the main reference. When the error between the output voltage of the calibration reference and the output voltage of the main reference is greater than the zero-point error, it is determined that the output voltage of the calibration reference has changed.

4. The voltage reference source calibration method according to claim 2 or 3, characterized in that, The method for determining the error compensation voltage is as follows: based on the current operating temperature of the calibration reference, find the corresponding error compensation voltage at each pre-calibrated operating temperature. The calibration process is as follows: test the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, determine the corresponding compensation coefficient based on the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, and calculate the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration in the production stage.

5. The voltage reference source calibration method according to claim 1, characterized in that, When adjusting the output voltage of the calibration reference based on the error compensation voltage, the output voltage of the calibration reference is adjusted step by step.

6. A self-calibrating voltage reference source, characterized in that, It includes a calibration reference, a temperature detection module, a feedback circuit module, and a self-calibration control module; the temperature detection module is used to acquire the operating temperature of the calibration reference in the voltage reference source; The self-calibration control module is used to trigger calibration periodically or when the change in the operating temperature of the calibration reference exceeds a temperature change threshold. The calibration process includes: using a feedback circuit module to detect the output voltage of the calibration reference; if the output voltage of the calibration reference changes, the self-calibration control module determines an error compensation voltage based on the current operating temperature of the calibration reference; adjusting the output voltage of the calibration reference based on the error compensation voltage; using the feedback circuit module to detect the adjusted output voltage of the calibration reference; if the output voltage of the calibration reference does not meet the reference voltage output requirement, the adjustment continues until the output voltage of the calibration reference meets the reference voltage output requirement, and then it is used as the reference voltage output. The error compensation voltage corresponding to meeting the reference voltage output requirement is updated to the error compensation voltage at that operating temperature; if it meets the requirement, it is directly used as the reference voltage output.

7. The self-calibrating voltage reference source according to claim 6, characterized in that, It also includes a primary reference, which is used to provide a reference voltage reference for the voltage reference source; The feedback circuit module is also connected to the main reference to obtain the error between the output voltage of the calibration reference and the output voltage of the main reference. When the error between the output voltage of the calibration reference and the output voltage of the main reference is less than or equal to the zero-point error, the output voltage of the calibration reference is deemed to meet the reference voltage output requirements. The zero-point error refers to the value at which the error between the output voltage of the calibration reference and the output voltage of the main reference meets the accuracy requirements of the voltage reference source after the voltage reference source is initialized and calibrated during the production stage.

8. The self-calibrating voltage reference source according to claim 7, characterized in that, The method for determining if the output voltage of the calibration reference has changed is as follows: when the error between the output voltage of the calibration reference obtained by the feedback circuit module and the output voltage of the main reference is greater than the zero-point error, it is determined that the output voltage of the calibration reference has changed.

9. The self-calibrating voltage reference source according to claim 7 or 8, characterized in that, The self-calibration control module determines the error compensation voltage based on the current operating temperature of the calibration reference by finding the corresponding error compensation voltage at each pre-calibrated operating temperature. The calibration process involves testing the deviation between the output voltage of the calibration reference and the output voltage of the main reference at each operating temperature, determining the corresponding compensation coefficient based on the deviation, and calculating the error compensation voltage based on the compensation coefficient and the output voltage of the calibration reference determined after initial calibration during the production stage.

10. The self-calibrating voltage reference source according to claim 9, characterized in that, The self-calibration control module stores the zero-point error and the error compensation voltage corresponding to each pre-calibrated operating temperature, and updates the error compensation voltage when the reference voltage output requirement is met at each operating temperature.

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