Offset calibration method, chip and electronic equipment
By updating calibration parameters in the analog-to-digital converter, the accuracy reduction problem caused by the offset voltage change of the analog-to-digital converter during long-term operation is solved, and high-precision measurements are achieved in harsh environments.
Patent Information
- Application Number
- CN202411327298.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-23
- Publication Date
- 2025-01-03
AI Technical Summary
Changes in offset voltages during long-term operation of the analog-to-digital converter lead to a decrease in measurement accuracy and an increase in error, especially in harsh environments, and it is difficult for the prior art to effectively update calibration parameters to cope with such changes.
An offset calibration method is provided, by judging whether the voltage measurement circuit meets preset conditions, measuring real-time offset data, and updating calibration parameters based on real-time and initial offset data, ensuring that the voltage measurement circuit maintains high accuracy during operation.
It effectively avoids the increase in measurement error caused by long-term work, ensures the accuracy and accuracy of the analog-to-digital converter, and is suitable for application scenarios in long-lived and harsh environments.
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Figure CN119254224A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of signal measurement, and in particular to an offset calibration method, a chip and an electronic device. Background Art
[0002] Analog Digital Converter (ADC) can convert voltage signals (such as electrical signals output by sensors) into digital signals and is widely used in communication, measurement, control, signal processing and other scenarios. Since the conversion accuracy of the ADC is affected by its offset voltage, the offset voltage of the ADC is usually calibrated before the ADC leaves the factory to ensure the high-precision measurement of the signal by the ADC.
[0003] However, the offset voltage calibrated at the factory may change slowly as the analog-to-digital converter works. For example, in some application scenarios that require a long life and have a harsh working environment (such as industry, automobiles, etc.), the offset voltage changes significantly with the working life (such as 5 years, 10 years or even longer), which ultimately leads to a decrease in the accuracy of the analog-to-digital converter calibrated at the factory and an increase in the measurement error. Summary of the invention
[0004] In view of the above problems, the embodiments of the present application provide an offset calibration method, a chip and an electronic device to solve the above technical problems.
[0005] In a first aspect, an embodiment of the present application provides an offset calibration method, which is applied to a voltage measurement circuit. The method includes:
[0006] determining whether the voltage measurement circuit meets a preset offset calibration condition;
[0007] When the voltage measurement circuit meets a preset offset calibration condition, measuring real-time offset data of the voltage measurement circuit;
[0008] Determine the calibration offset parameters of the voltage measurement circuit based on the real-time offset data and the initial offset data. The initial offset data is the calibration offset parameters determined in the last calibration process of the voltage measurement circuit.
[0009] In a second aspect, an embodiment of the present application further provides a chip, including a voltage measurement circuit, wherein the voltage measurement circuit updates a calibration offset parameter using the offset calibration method as described in the first aspect.
[0010] In a third aspect, an embodiment of the present application further provides an electronic device comprising the above-mentioned chip.
[0011] When the voltage measurement circuit (e.g., an analog-to-digital converter) meets a preset offset calibration condition, the present application measures the real-time offset data of the voltage measurement circuit during operation, thereby updating the calibration offset parameters of the voltage measurement circuit according to the real-time offset data of the voltage measurement circuit and the initial offset data determined in the last calibration process of the voltage measurement circuit. In other words, the offset calibration method of the present application can update the calibration offset parameters of the voltage measurement circuit during the operation of the voltage measurement circuit, thereby avoiding the phenomenon that the offset parameters calibrated before the voltage measurement circuit leaves the factory become invalid due to long-term operation and the measurement error increases.
[0012] These and other aspects of the present application will become more clearly understood in the description of the following embodiments. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.
[0014] Figure 1 A schematic diagram of correcting the output digital signal of an analog-to-digital converter in the related art is shown.
[0015] Figure 2 A schematic flow chart of an offset calibration method in an embodiment of the present application is shown.
[0016] Figure 3 A schematic diagram of determining a calibration offset parameter in an embodiment of the present application is shown.
[0017] Figure 4 A schematic diagram of a process for measuring real-time imbalance data in an embodiment of the present application is shown.
[0018] Figure 5 A schematic diagram of a flow chart for determining whether an offset calibration condition is met in an embodiment of the present application is shown. DETAILED DESCRIPTION
[0019] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.
[0020] In order to enable those skilled in the art to better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work are within the scope of protection of the present application.
[0021] In the embodiments of the present application, it should be noted that, in this article, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.
[0022] Moreover, the terms "comprises," "comprising," or any other variation thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.
[0023] In the description of the embodiments of the present application, words such as "example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described as "example" or "for example" in the embodiments of the present application is not to be interpreted as being more preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to present relative concepts in a clear manner.
[0024] In addition, the "plurality" in the embodiments of the present application refers to two or more than two. In view of this, in the embodiments of the present application, "plurality" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no limit on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A, B and C can be included.
[0025] At present, in order to ensure the high-precision measurement of the signal by the analog-to-digital converter, the offset voltage of the analog-to-digital converter is usually calibrated before the analog-to-digital converter leaves the factory and the parameters are saved in the corresponding registers. Figure 1 , Figure 1A schematic diagram of the correction of the digital signal output by the analog-to-digital converter in the related art is shown. The parameter Dvos corresponding to the offset voltage Vos calibrated before the analog-to-digital converter leaves the factory is stored in the register. After the analog-to-digital converter performs analog-to-digital conversion on the input voltage Vin and outputs the digital signal Din (including the conversion result of the offset voltage Vos), the digital circuit (such as a subtractor) can perform arithmetic operations according to the parameter Dvos in the register and the digital signal Din and output the calibrated digital signal Dout. The calibrated digital signal Dout can satisfy the following formula:
[0026] Dout=Din-Dvos
[0027] It can be seen that the calibrated digital signal Dout can eliminate the influence of the offset voltage Vos of the analog-to-digital converter, thereby achieving high-precision measurement of the analog signal. However, the offset voltage of the analog-to-digital converter may change slowly over time, so that the parameter Dvos stored in the register does not correspond to the actual offset voltage of the analog-to-digital converter, which may cause the accuracy of the calibrated analog-to-digital converter to decrease and the measurement error to increase.
[0028] To this end, the present application provides an offset calibration method, a chip and an electronic device, which are described in detail below.
[0029] First, see Figure 2 , Figure 2 A schematic flow chart of an offset calibration method in an embodiment of the present application is shown, wherein the offset calibration method is applied to a voltage measurement circuit, and the offset calibration method includes:
[0030] Step S201, determining whether the voltage measurement circuit meets a preset offset calibration condition;
[0031] Specifically, the voltage measurement circuit includes an analog-to-digital converter to convert the analog voltage of the input voltage measurement circuit into a digital signal, wherein the analog-to-digital converter may be, but is not limited to, a hybrid analog-to-digital converter consisting of one or more of a successive approximation analog-to-digital converter (SAR ADC), a Sigma-Delta analog-to-digital converter (SD ADC), a pipeline analog-to-digital converter (Pipeline ADC), or a ramp-compare analog-to-digital converter (Ramp-compare ADC).
[0032] The preset offset calibration condition is a condition for determining whether to update the offset parameters of the voltage measurement circuit. If the voltage measurement circuit meets the preset offset calibration condition, the offset parameters stored in the register of the voltage measurement circuit can be updated; conversely, if the voltage measurement circuit does not meet the preset offset calibration condition, the offset parameters of the voltage measurement circuit stored in the register can be retained, so that the voltage measurement circuit still uses the original offset parameters for calibration.
[0033] In some embodiments of the present application, the preset offset calibration condition may be that the measurement error of the voltage measurement circuit exceeds a certain threshold value, for example, when the voltage measurement circuit measures a 3V voltage, and the measurement result of the voltage measurement circuit corresponds to 3.1V, the measurement error of 0.1V exceeds 0.05V, so it can be judged that the voltage measurement circuit meets the preset offset calibration condition. In some embodiments of the present application, the preset offset calibration condition may be that the voltage measurement circuit has been away from the time when the offset parameter was last updated for more than a certain period of time, for example, when the voltage measurement circuit has been away from the time when the offset parameter was last updated for more than 24 hours, it can be judged that the voltage measurement circuit meets the preset offset calibration condition.
[0034] It can be understood that the preset offset calibration conditions are not limited to this. Those skilled in the art can set corresponding preset offset calibration conditions according to actual needs. For example, the external ambient temperature change is set as the offset calibration condition. When the external ambient temperature change exceeds a certain value, it can be determined that the voltage measurement circuit meets the preset offset calibration condition.
[0035] Step S202, when the voltage measurement circuit meets the preset offset calibration condition, measuring the real-time offset data of the voltage measurement circuit;
[0036] When the voltage measurement circuit meets the preset offset calibration condition, the real-time offset data of the voltage measurement circuit can be measured. In some embodiments of the present application, the input terminal of the voltage measurement circuit can be controlled to be grounded (equivalent to the input voltage being zero), and at this time, the voltage measurement circuit is equivalent to measuring its offset voltage, so the measurement result output by the voltage measurement circuit corresponds to the real-time offset data of the offset voltage of the voltage measurement circuit. For example, when the input terminal of the voltage measurement circuit is grounded, and the voltage corresponding to the digital output signal converted by the voltage measurement circuit to the analog input signal is 0.1V, it can be determined that the real-time offset data is 0.1V.
[0037] In some embodiments of the present application, the voltage measurement circuit can also be controlled to access an analog input signal of a known voltage, and after the voltage measurement circuit converts the analog input signal into a digital output signal, the real-time offset data can be calculated based on the analog input signal of the known voltage and the digital output signal. For example, when the voltage of the analog input signal is 2V, and the voltage corresponding to the digital output signal converted by the voltage measurement circuit to the analog input signal is 2.1V, the real-time offset data can be determined to be 0.1V.
[0038] Step S203, determining a calibration offset parameter of a voltage measurement circuit according to the real-time offset data and the initial offset data;
[0039] After the real-time offset data of the voltage measurement circuit is determined, the calibration offset parameters of the voltage measurement circuit can be determined according to the real-time offset data and the initial offset data. The initial offset data can be stored in a corresponding register, and the initial offset data is the calibration offset parameter determined in the last calibration process of the voltage measurement circuit. For example, when the voltage measurement circuit updates the offset parameter for the first time during operation, the initial offset data is the calibration offset parameter determined by the voltage measurement circuit before leaving the factory; for another example, when the voltage measurement circuit updates the offset parameter for the second time during operation, the initial offset data is the calibration offset parameter determined when the voltage measurement circuit updates the offset parameter for the first time during operation, and so on, which will not be repeated here.
[0040] In some embodiments of the present application, the average value of the real-time offset data and the initial offset data can be calculated, and then the average value is used as the calibration offset parameter updated by the voltage measurement circuit, and the updated calibration offset parameter is saved in the corresponding register. In some embodiments of the present application, the offset data and the initial offset data can also be summed in a certain ratio as the calibration offset parameter updated by the voltage measurement circuit, and the updated calibration offset parameter is saved in the corresponding register.
[0041] In an embodiment of the present application, when a voltage measurement circuit (such as an analog-to-digital converter) meets a preset offset calibration condition, the present application measures real-time offset data during the operation of the voltage measurement circuit, thereby updating the calibration offset parameters of the voltage measurement circuit according to the real-time offset data of the voltage measurement circuit and the initial offset data determined in the last calibration process of the voltage measurement circuit. In other words, the offset calibration method of the present application can update the calibration offset parameters of the voltage measurement circuit during the operation of the voltage measurement circuit, thereby avoiding the phenomenon that the offset parameters calibrated before the voltage measurement circuit leaves the factory become invalid due to long-term operation, resulting in an increase in its measurement error.
[0042] It should be noted that when measuring the real-time offset data of the voltage measurement circuit in step S202, the measured real-time offset data may contain additional error noise due to external factors such as ambient temperature change, current change or voltage change, thereby causing the calibration offset parameter determined in step S203 to introduce additional errors. To further solve this technical problem, please continue to refer to the following content.
[0043] In some embodiments of the present application, see Figure 3 , Figure 3 A schematic diagram of determining a calibration offset parameter in an embodiment of the present application is shown, wherein the step of determining the calibration offset parameter of the voltage measurement circuit according to the real-time offset data and the initial offset data includes:
[0044] Step S301, obtaining an offset voltage influencing parameter, where the offset voltage influencing parameter includes at least one of an ambient temperature change, a current change, or a voltage change before and after a voltage measurement circuit measures real-time offset data;
[0045] For example, when the offset voltage influencing parameter includes the ambient temperature change, the first ambient temperature of the voltage measurement circuit before measuring the real-time offset data can be obtained first, and then the second ambient temperature of the voltage measurement circuit after measuring the real-time offset data can be obtained, and finally the difference between the first ambient temperature and the second ambient temperature is used as the ambient temperature change, so as to determine the degree of influence on the real-time offset data according to the ambient temperature change.
[0046] For another example, when the offset voltage influencing parameter includes a current variation, a first current at which the voltage measurement circuit operates before measuring the real-time offset data may be first obtained, and then a second current at which the voltage measurement circuit operates after measuring the real-time offset data may be obtained, and finally a difference between the first current and the second current is used as the current variation, so as to determine the degree of influence on the real-time offset data according to the current variation.
[0047] For another example, when the offset voltage influencing parameter includes a voltage variation, a first voltage at which the voltage measurement circuit works before measuring the real-time offset data may be first obtained, and then a second voltage at which the voltage measurement circuit works after measuring the real-time offset data may be obtained, and finally a difference between the first voltage and the second voltage is used as the voltage variation, so as to determine the degree of influence on the real-time offset data according to the voltage variation.
[0048] Step S302, determining an offset weight coefficient according to an offset voltage influencing parameter and a preset influencing parameter-weight coefficient mapping relationship;
[0049] The preset influencing parameter-weight coefficient mapping relationship refers to the mapping relationship between the offset voltage influencing parameter and the offset weight coefficient. When the offset voltage influencing parameter is known, the corresponding offset weight coefficient can be determined through the offset voltage influencing parameter and the preset influencing parameter-weight coefficient mapping relationship.
[0050] In some embodiments of the present application, the preset influence parameter-weight coefficient mapping relationship may refer to a data mapping table of offset voltage influence parameters and offset weight coefficients. By querying the data mapping table according to the offset voltage influence parameters, the corresponding offset weight coefficient can be determined. In some embodiments of the present application, the preset influence parameter-weight coefficient mapping relationship may refer to a mapping relationship satisfied between the offset voltage influence parameter and the offset weight coefficient. The corresponding offset weight coefficient can be calculated according to the offset voltage influence parameter and the mapping relationship.
[0051] As an example, taking the offset voltage influencing parameters including the ambient temperature change as an example, if the ambient temperature change is less than or equal to 5°C, the offset weight coefficient can be determined to be 0.1 according to the preset influencing parameter-weight coefficient mapping relationship; if the ambient temperature change is greater than 5°C and less than 10°C, the offset weight coefficient can be determined to be 0.5 according to the preset influencing parameter-weight coefficient mapping relationship; if the ambient temperature change is greater than or equal to 10°C, the offset weight coefficient can be determined to be 0.9 according to the preset influencing parameter-weight coefficient mapping relationship.
[0052] Step S303, determining a calibration offset parameter of the voltage measurement circuit according to the offset weight coefficient, the real-time offset data and the initial offset data.
[0053] After determining the offset voltage influencing parameters, the calibration offset parameters of the voltage measurement circuit are determined according to the offset weight coefficient, the real-time offset data, and the initial offset data. As an example, the updated calibration offset parameters can be calculated according to the following formula:
[0054] Vos_new=(Vos_rt-Vos_old)*K+Vos_old
[0055] Among them, Vos_new is the updated calibration offset parameter, Vos_rt is the real-time offset data, Vos_old is the initial offset data, and K is the offset weight coefficient.
[0056] It can be seen from the above formula that for an embodiment in which the ambient temperature change is less than or equal to 5°C and the offset weight coefficient is 0.1, the calibration offset parameter updated by the above formula has a small change relative to the initial offset data; for an embodiment in which the ambient temperature change is greater than 5°C and less than 10°C and the offset weight coefficient is 0.5, the calibration offset parameter updated by the above formula has a certain change relative to the initial offset data; for an embodiment in which the ambient temperature change is greater than 10°C and the offset weight coefficient is 0.9, the calibration offset parameter updated by the above formula has a large change relative to the initial offset data, so the update speed of the calibration offset parameter is reduced by the offset weight coefficient, which is beneficial to reducing the additional error introduced by the calibration offset parameter due to external factors such as ambient temperature changes, current changes or voltage changes, thereby making the update process of the calibration offset parameter smoother.
[0057] It can be understood that the above calculation formula for calibrating the offset parameter is only for example. In some possible embodiments, the offset weight coefficient may also include multiple parameters. For example, the calculation formula for calibrating the offset parameter may also be Vos_new=(Vos_rt-Vos_old)*K1+Vos_old*K2, where K1 and K2 are the offset weight coefficients determined in step S302.
[0058] In some embodiments of the present application, see Figure 4 , Figure 4 A schematic diagram of a process for measuring real-time offset data in an embodiment of the present application is shown, wherein the step of measuring real-time offset data of a voltage measurement circuit includes:
[0059] Step S401, controlling the voltage measurement circuit to measure the input voltage of zero voltage to obtain a measurement data set corresponding to the input voltage of zero voltage;
[0060] Specifically, the voltage measurement circuit can measure the input voltage of zero once or multiple times. When the voltage measurement circuit measures the input voltage of zero only once, the measurement data set includes a single measurement data corresponding to the measured input voltage of zero; when the voltage measurement circuit measures the input voltage of zero multiple times, the measurement data set includes multiple data results of measuring the input voltage of zero multiple times.
[0061] It should be noted that the voltage measurement circuit can be integrated into the target chip, and the target chip can be but not limited to a SOC (System on Chip) chip or a SIP (system in package) chip. The input voltage of zero voltage can be provided by an internal circuit of the target chip (such as a digital-to-analog converter in the chip), or the input voltage of zero voltage can be provided by an external circuit connected to the target chip (such as a digital-to-analog converter on a circuit board).
[0062] Step S402: determining real-time offset data of a voltage measurement circuit according to a measurement data set.
[0063] After determining the measurement data set corresponding to the input voltage with voltage zero, the real-time offset data of the voltage measurement circuit can be determined according to the measurement data set. In some embodiments of the present application, when the voltage measurement circuit measures the input voltage with voltage zero only once, and the measurement data set includes a single measurement data, the single measurement data can be used as the real-time offset data of the voltage measurement circuit.
[0064] In some embodiments of the present application, when a voltage measurement circuit measures an input voltage of zero voltage multiple times, and a measurement data set includes multiple measurement data, the real-time offset data of the voltage measurement circuit can be determined after performing mathematical operations on the multiple measurement data. For example, the arithmetic mean of the multiple measurement data can be used as the real-time offset data of the voltage measurement circuit; for another example, the weighted average of the multiple measurement data can be used as the real-time offset data of the voltage measurement circuit, so as to reduce the measurement noise of the voltage measurement circuit for the input voltage of zero voltage.
[0065] In some embodiments of the present application, when the input voltage with a voltage of zero is provided by an internal circuit of the target chip, the step of determining the real-time offset data of the voltage measurement circuit according to the measurement data set includes:
[0066] Determine real-time offset data of a voltage measurement circuit according to the measurement data set and the chip offset voltage;
[0067] The chip offset voltage is the offset voltage corresponding to the input voltage of zero when the output voltage of the internal circuit of the target chip is zero.
[0068] It should be noted that when the input voltage of zero voltage is provided by the internal circuit of the target chip, the internal circuit of the target chip may generate an offset voltage due to the mismatch of electronic components, resulting in the input voltage input to the voltage measurement circuit not being zero. Therefore, when determining the real-time offset data of the voltage measurement circuit, the real-time offset data can be determined by combining the chip offset voltage and the measurement data set. For example, the real-time offset data of the voltage measurement circuit can be determined according to the following formula:
[0069] Vos_rt=Vos_me-Vos0
[0070] Among them, Vos_me is the arithmetic mean of multiple measurement data in the measurement data set, and Vos0 is the chip offset voltage (which can be pre-tested and saved in the corresponding register).
[0071] It can be seen that when the input voltage with a voltage of zero is provided by the internal circuit of the target chip, the above embodiment can eliminate the influence of the chip offset voltage, thereby facilitating further improving the offset calibration accuracy of the voltage measurement circuit.
[0072] In some embodiments of the present application, see Figure 5 , Figure 5 A flow chart of determining whether an offset calibration condition is satisfied in an embodiment of the present application is shown, wherein the step of determining whether a voltage measurement circuit satisfies a preset offset calibration condition comprises:
[0073] Step S501, controlling the voltage measurement circuit to collect a signal to be measured whose voltage is known, and outputting corresponding voltage measurement data;
[0074] Step S502, calibrating the voltage measurement data according to the initial offset data to determine the calibration measurement data corresponding to the signal to be measured;
[0075] Step S503: judging whether the voltage measurement circuit satisfies a preset offset calibration condition according to the signal to be measured and the calibration measurement data.
[0076] It should be noted that after the voltage measurement circuit collects the signal to be measured with a known voltage, the voltage measurement data corresponding to its output includes the offset voltage of the voltage measurement circuit. After the measurement data is calibrated with the initial offset data, the measurement error caused by the offset voltage in the calibrated measurement data relative to the signal to be measured will be reduced. Therefore, by comparing the calibrated measurement data with the signal to be measured after calibration, the calibration degree of the calibrated measurement data corrected by the initial offset data can be determined, whether the measurement error caused by the offset voltage can be calibrated to less than the set threshold through the initial offset data, and finally whether the voltage measurement circuit meets the preset offset calibration conditions.
[0077] For example, the voltage value of the signal to be measured is 3V, and the voltage measurement data output by the voltage measurement circuit is 3.2V. After the initial offset data is corrected, the calibration measurement data corresponding to the signal to be measured is determined to be 3.1V. Therefore, the calibration measurement data after calibration has a measurement error of 0.1V relative to the signal to be measured caused by the offset voltage. The measurement error of 0.1V exceeds the set threshold of 0.05V. Therefore, it can be judged that the voltage measurement circuit meets the preset offset calibration condition, and the offset parameters of the voltage measurement circuit need to be re-determined. After updating the calibration offset parameters, the voltage measurement data can be calibrated using the updated calibration offset parameters to make the error less than 0.05V.
[0078] In some embodiments of the present application, the signal to be measured includes multiple groups of voltages to be measured, and the calibration measurement data includes multiple groups of voltage calibration results calibrated by initial offset data; the step of judging whether the voltage measurement circuit meets the preset offset calibration condition based on the signal to be measured and the calibration measurement data includes: determining the standard deviation of the multiple groups of voltages to be measured and the multiple groups of voltage calibration results, and judging whether the voltage measurement circuit meets the preset offset calibration condition based on the standard deviation.
[0079] That is to say, in step S501, the voltage measurement circuit can collect multiple voltages to be measured whose voltages are known and output multiple voltage measurement data. Then, in step S502, the multiple voltage measurement data can be calibrated according to the initial offset data and multiple calibration measurement data can be determined, so as to judge whether the standard deviation of the multiple groups of voltages to be measured and the multiple groups of calibration data is less than the set threshold in step S503, and finally judge whether the voltage measurement circuit meets the preset offset calibration condition, so that the judgment of whether the voltage measurement circuit meets the preset offset calibration condition is more accurate.
[0080] It should be pointed out that the above embodiments are intended to clearly illustrate the implementation verification process of the offset calibration method of the present application. Under the guidance of the present application, those skilled in the art can also make equivalent modified designs. For example, for an embodiment in which the measured signal includes multiple groups of measured voltages, and the calibration measurement data includes multiple groups of voltage calibration data corresponding to the multiple groups of measured voltages, step S503 can also determine whether the voltage measurement circuit meets the preset offset calibration condition based on the variance of the multiple groups of measured voltages and the multiple groups of voltage calibration data.
[0081] The embodiment of the present application also provides a chip, the chip includes a voltage measurement circuit, and the voltage measurement circuit uses the offset calibration method described in any of the above embodiments to update the calibration offset parameters. A chip (Integrated Circuit, IC) is also called a chip, and the chip can be, but is not limited to, a SOC (System on Chip, chip-level system) chip or a SIP (system in package, system-level packaging) chip. Since the voltage measurement circuit of the chip of the present application uses the offset calibration method as described above to update the calibration offset parameters, it has all the beneficial effects of the offset calibration method in the above embodiments, which will not be repeated here.
[0082] The embodiment of the present application also provides an electronic device, which includes a device body and a chip as described above provided in the device body. The electronic device may be, but is not limited to, a weight scale, a body fat scale, a nutrition scale, an infrared electronic thermometer, a pulse oximeter, a human body composition analyzer, a mobile power supply, a wireless charger, a fast charger, a car charger, an adapter, a display, a USB (Universal Serial Bus) docking station, a stylus, a true wireless headset, a car central control screen, a car, a smart wearable device, a mobile terminal, and a smart home device. Smart wearable devices include, but are not limited to, smart watches, smart bracelets, and cervical massagers. Mobile terminals include, but are not limited to, smart phones, laptops, tablet computers, and POS (point of sales terminal). Smart home devices include, but are not limited to, smart sockets, smart rice cookers, smart sweepers, and smart lights.
[0083] The above are only preferred embodiments of the present application, and are not intended to limit the present application in any form. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technical personnel in the field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.
Claims
1. An offset calibration method, characterized in that: The offset calibration method is applied to a voltage measurement circuit, and the method comprises: Determining whether the voltage measurement circuit meets a preset offset calibration condition; When the voltage measurement circuit meets the preset offset calibration condition, measuring real-time offset data of the voltage measurement circuit; A calibration offset parameter of the voltage measurement circuit is determined according to the real-time offset data and the initial offset data, wherein the initial offset data is a calibration offset parameter determined in a previous calibration process of the voltage measurement circuit.
2. The offset calibration method according to claim 1, characterized in that: The step of determining the calibration offset parameter of the voltage measurement circuit according to the real-time offset data and the initial offset data comprises: Acquire an offset voltage influence parameter, wherein the offset voltage influence parameter includes at least one of an ambient temperature change, a current change, or a voltage change before and after the voltage measurement circuit measures the real-time offset data; Determining an offset weight coefficient according to the offset voltage influencing parameter and a preset influencing parameter-weight coefficient mapping relationship; A calibration offset parameter of the voltage measurement circuit is determined according to the offset weight coefficient, the real-time offset data, and the initial offset data.
3. The offset calibration method according to claim 1, wherein: The step of measuring the real-time offset data of the voltage measurement circuit comprises: Controlling the voltage measurement circuit to measure an input voltage with a voltage of zero, so as to obtain a set of measurement data corresponding to the input voltage with a voltage of zero; Real-time offset data of the voltage measurement circuit is determined based on the set of measurement data.
4. The offset calibration method according to claim 3, characterized in that: The measurement data set includes a plurality of measurement data of the input voltage having a voltage of zero measured by the voltage measurement circuit for a plurality of times; The step of determining the real-time offset data of the voltage measurement circuit according to the measurement data set comprises: The real-time offset data of the voltage measurement circuit is determined according to an average value of a plurality of the measurement data.
5. The offset calibration method according to claim 3, characterized in that: The voltage measurement circuit is integrated into the target chip; The input voltage of zero voltage is provided by an internal circuit of the target chip, or the input voltage of zero voltage is provided by an external circuit connected to the target chip.
6. The offset calibration method according to claim 5, characterized in that: The input voltage with a voltage of zero is provided by an internal circuit of the target chip; The step of determining the real-time offset data of the voltage measurement circuit according to the measurement data set comprises: Determining real-time offset data of the voltage measurement circuit according to the measurement data set and the chip offset voltage; The chip offset voltage is the offset voltage corresponding to the input voltage when the output voltage of the internal circuit of the target chip is zero.
7. The offset calibration method according to claim 1, wherein: The step of determining whether the voltage measurement circuit meets a preset offset calibration condition comprises: Controlling the voltage measurement circuit to collect a signal to be measured whose voltage is known, and outputting corresponding voltage measurement data; calibrating the voltage measurement data according to the initial offset data to determine calibration measurement data corresponding to the signal to be measured; According to the signal to be measured and the calibration measurement data, it is determined whether the voltage measurement circuit meets the preset offset calibration condition.
8. The offset calibration method according to claim 7, wherein: The signal to be measured includes a plurality of groups of voltages to be measured, and the calibration measurement data includes a plurality of groups of voltage calibration results calibrated by the initial offset data; The step of judging whether the voltage measurement circuit satisfies the preset offset calibration condition according to the signal to be measured and the calibration measurement data comprises: Determine the standard deviations of the plurality of groups of voltages to be measured and the plurality of groups of voltage calibration results, and judge whether the voltage measurement circuit satisfies the preset offset calibration condition according to the standard deviations.
9. A chip, characterized in that: The method comprises a voltage measurement circuit, wherein the voltage measurement circuit updates a calibration offset parameter using the offset calibration method according to any one of claims 1 to 8.
10. An electronic device, characterized in that: Comprising the chip as claimed in claim 9.