Analog-to-digital conversion device, digital signal calibration method and device

Abstract

The present specification provides an analog-to-digital conversion device, a calibration method and an apparatus for digital signals. The analog-to-digital conversion device includes a multi-stage analog-to-digital conversion module. A comparison module is connected between each stage of the analog-to-digital conversion module. The comparison module calculates a secondary voltage sampling signal that cannot be accurately processed by the previous stage of the analog-to-digital conversion module and inputs it to the next stage of the analog-to-digital conversion module for further processing. The calibration coefficients of all previous analog-to-digital conversion modules are determined based on the subsequent analog-to-digital conversion module. The calibrated conversion numbers output by all analog-to-digital conversion modules are calculated in a digital logic processing module as digital representations corresponding to the voltage sampling signals. Ultimately, it is ensured that the digital representation effect of a single analog-to-digital converter with high resolution can be achieved by using multiple low-resolution analog-to-digital conversion modules and the accuracy of the calibrated digital representation can also reach the accuracy level of the single analog-to-digital converter.

Description

Technical Field

[0001] The present invention relates to the field of integrated circuit technology, and in particular to analog-to-digital conversion equipment, and digital signal calibration methods and devices. Background Art

[0002] Analog-to-Digital Converter (ADC) is an electronic device that converts continuous analog signals (such as voltage, current, sound signal, etc.) into discrete digital signals. By sampling and quantizing analog signals into digital signals, computers or digital processing systems can process and store these digital signals.

[0003] The key performance of an analog-to-digital converter is resolution. The higher the resolution, the more accurately the analog-to-digital converter can capture subtle voltage changes and provide a more precise digital representation. Related technologies generally improve the processing accuracy of the analog-to-digital converter by increasing the resolution of the analog-to-digital converter. However, the resolution of the analog-to-digital converter is positively correlated with its circuit scale and design complexity. Therefore, although increasing the resolution of the analog-to-digital converter can improve processing accuracy, it also introduces many design, cost and performance challenges. Summary of the invention

[0004] In order to overcome the problems existing in the related art, this specification provides an analog-to-digital conversion device, a digital signal calibration method and an apparatus.

[0005] According to a first aspect of an embodiment of this specification, an analog-to-digital conversion device is provided, the device comprising a digital logic processing module, a plurality of analog-to-digital conversion modules and at least one comparison module, each analog-to-digital conversion module is sequentially connected to each comparison module at intervals and the least significant bit value LSB of the subsequent analog-to-digital conversion module is less than the LSB of the previous analog-to-digital conversion module, each analog-to-digital conversion module is respectively connected to the digital logic processing module, wherein:

[0006] The first analog-to-digital conversion module is used to receive a voltage sampling signal, and output a conversion number corresponding to the voltage sampling signal to the digital logic processing module, output a voltage conversion signal corresponding to the conversion number to the first comparison module, and output a minimum voltage conversion signal representing its LSB size to its next analog-to-digital conversion module;

[0007] The first comparison module is used to receive the voltage sampling signal, and input the difference between the voltage sampling signal and the voltage conversion signal output by the first analog-to-digital conversion module as a secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module respectively;

[0008] Each comparison module except the first comparison module is used to output the difference between the secondary voltage sampling signal output by the previous comparison module and the voltage conversion signal output by the previous analog-to-digital conversion module as a new secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module;

[0009] Each analog-to-digital conversion module except the first analog-to-digital conversion module is used to output the minimum voltage conversion signal output by the previous analog-to-digital conversion module and the secondary voltage sampling signal output by the previous comparison module to the digital logic processing module, output the voltage conversion signal corresponding to the conversion number to the next comparison module, and output the minimum voltage conversion signal representing its LSB size to the next analog-to-digital conversion module;

[0010] The digital logic processing module is used to determine, based on the received conversion digits and minimum voltage digits, for each analog-to-digital conversion module except the first analog-to-digital conversion module, the calibration coefficient of the conversion digit output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digit output by the module and the LSB of the previous analog-to-digital conversion module; and, based on the calibration coefficient, calibrate the conversion digit output by the at least one analog-to-digital conversion module to obtain a calibrated conversion digit, and determine the sum of all calibrated conversion digits and uncalibrated conversion digits as the digital representation corresponding to the voltage sampling signal.

[0011] According to a second aspect of an embodiment of this specification, a method for calibrating a digital signal is provided, the method being applied to a digital logic processing module in the analog-to-digital conversion device as described in the first aspect, comprising:

[0012] Obtain the conversion numbers and minimum voltage numbers respectively input by each analog-to-digital conversion module;

[0013] For each analog-to-digital conversion module except the first analog-to-digital conversion module, determine the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digital output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module;

[0014] The conversion numbers output by the at least one analog-to-digital conversion module are calibrated based on the calibration coefficient to obtain calibrated conversion numbers, and the sum of all calibrated conversion numbers and uncalibrated conversion numbers is determined as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

[0015] According to a third aspect of the embodiments of this specification, a digital signal calibration device is provided, the device is applied to a digital logic processing module in the analog-to-digital conversion device as described in the first aspect, and the device includes:

[0016] An acquisition module, used for acquiring conversion numbers and minimum voltage numbers respectively input by each analog-to-digital conversion module;

[0017] A calibration coefficient determination module, for each analog-to-digital conversion module except the first analog-to-digital conversion module, determining a calibration coefficient of a conversion number output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage number output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module;

[0018] A digital representation calibration module is used to calibrate the conversion digital output by the at least one analog-to-digital conversion module based on the calibration coefficient to obtain a calibrated conversion digital, and determine the sum of all calibrated conversion digitals and uncalibrated conversion digitals as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

[0019] According to a fourth aspect of an embodiment of this specification, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method described in the second aspect are implemented.

[0020] According to a fifth aspect of the embodiments of this specification, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps of the method described in the second aspect are implemented.

[0021] The technical solutions provided by the embodiments of this specification may have the following beneficial effects:

[0022] The analog-to-digital conversion device designed in this scheme includes a multi-stage analog-to-digital conversion module, and a comparison module is connected between each stage of the analog-to-digital conversion module. The secondary voltage sampling signal that cannot be accurately processed by the previous stage of the analog-to-digital conversion module is calculated by the comparison module, and is input into the next stage of the analog-to-digital conversion module for further processing. The calibration coefficients of all the previous analog-to-digital conversion modules are determined based on the latter analog-to-digital conversion module. The calibrated conversion numbers output by all the analog-to-digital conversion modules are calculated in the digital logic processing module as the digital representation corresponding to the voltage sampling signal. Finally, it is ensured that the digital representation effect of a single analog-to-digital converter with high resolution can be achieved by using multiple low-resolution analog-to-digital conversion modules, and the accuracy of the calibrated digital representation can also reach the accuracy level of the single analog-to-digital converter.

[0023] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the specification and, together with the description, serve to explain the principles of the specification.

[0025] Figure 1 It is a structural schematic diagram of an analog-to-digital conversion device including two analog-to-digital conversion modules according to an exemplary embodiment of this specification.

[0026] Figure 2 This is a schematic diagram of an analog-to-digital conversion device including two analog-to-digital conversion modules performing analog-to-digital conversion processing according to an exemplary embodiment of this specification.

[0027] Figure 3 It is a schematic diagram of determining a calibration coefficient of an analog-to-digital conversion device including two analog-to-digital conversion modules according to an exemplary embodiment of this specification.

[0028] Figure 4 It is a structural schematic diagram of an analog-to-digital conversion device including three analog-to-digital conversion modules according to an exemplary embodiment of this specification.

[0029] Figure 5 This is a schematic diagram of an analog-to-digital conversion device including three analog-to-digital conversion modules performing analog-to-digital conversion processing according to an exemplary embodiment of this specification.

[0030] Figure 6 It is a schematic diagram of determining a calibration coefficient of an analog-to-digital conversion device including three analog-to-digital conversion modules according to an exemplary embodiment of this specification.

[0031] Figure 7 The flowchart of a digital signal calibration method is shown in this specification according to an exemplary embodiment.

[0032] Figure 8 It is a structural schematic diagram of an electronic device according to an exemplary embodiment of the present specification.

[0033] Fig. 9 It is a block diagram of a digital signal calibration device shown in this specification according to an exemplary embodiment. DETAILED DESCRIPTION

[0034] The key performance of an analog-to-digital converter is resolution. The higher the resolution, the more accurately the analog-to-digital converter can capture subtle voltage changes and provide a more precise digital representation. Related technologies generally improve the conversion accuracy of the analog-to-digital converter by increasing the resolution of the analog-to-digital converter. However, the resolution of the analog-to-digital converter is positively correlated with its circuit scale and design complexity. Therefore, although increasing the resolution of the analog-to-digital converter can improve the conversion accuracy, it also introduces many design, cost and performance challenges.

[0035] In view of the above technical problems, the present invention proposes an analog-to-digital conversion device, which realizes the high conversion accuracy of a single high-resolution analog-to-digital converter by cooperating with multiple levels of coarse-resolution analog-to-digital converters.

[0036] Specifically, the analog-to-digital conversion device includes a digital logic processing module, a plurality of analog-to-digital conversion modules and at least one comparison module, each analog-to-digital conversion module is sequentially connected to each comparison module at intervals, and the least significant bit value LSB of the subsequent analog-to-digital conversion module is less than the LSB of the previous analog-to-digital conversion module, and each analog-to-digital conversion module is respectively connected to the digital logic processing module, wherein:

[0037] The first analog-to-digital conversion module is used to receive a voltage sampling signal, and output a conversion number corresponding to the voltage sampling signal to the digital logic processing module, output a voltage conversion signal corresponding to the conversion number to the first comparison module, and output a minimum voltage conversion signal representing its LSB size to its next analog-to-digital conversion module;

[0038] The first comparison module is used to receive the voltage sampling signal, and input the difference between the voltage sampling signal and the voltage conversion signal output by the first analog-to-digital conversion module as a secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module respectively;

[0039] Each comparison module except the first comparison module is used to output the difference between the secondary voltage sampling signal output by the previous comparison module and the voltage conversion signal output by the previous analog-to-digital conversion module as a new secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module;

[0040] Each analog-to-digital conversion module except the first analog-to-digital conversion module is used to output the minimum voltage conversion signal output by the previous analog-to-digital conversion module and the secondary voltage sampling signal output by the previous comparison module to the digital logic processing module, output the voltage conversion signal corresponding to the conversion number to the next comparison module, and output the minimum voltage conversion signal representing its LSB size to the next analog-to-digital conversion module;

[0041] The digital logic processing module is used to determine, based on the received conversion digits and minimum voltage digits, for each analog-to-digital conversion module except the first analog-to-digital conversion module, the calibration coefficient of the conversion digit output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digit output by the module and the LSB of the previous analog-to-digital conversion module; and, based on the calibration coefficient, calibrate the conversion digit output by the at least one analog-to-digital conversion module to obtain a calibrated conversion digit, and determine the sum of all calibrated conversion digits and uncalibrated conversion digits as the digital representation corresponding to the voltage sampling signal.

[0042] In order to make it easier for those skilled in the art to understand the inventive concept of the present scheme, the following will provide examples of analog-to-digital conversion devices including two analog-to-digital conversion modules and three analog-to-digital conversion modules, so that those skilled in the art can undoubtedly infer the design structure of the analog-to-digital conversion device including n analog-to-digital conversion modules based on this structure, where n is greater than or equal to 4.

[0043] like Figure 1 As shown, Figure 1 It is a structural schematic diagram of an analog-to-digital conversion device including two analog-to-digital conversion modules shown in an embodiment of this specification. The analog-to-digital conversion device 1 includes an analog-to-digital conversion module 10A, an analog-to-digital conversion module 10B, a comparison module 11A and a digital logic processing module 12. The input end of the analog-to-digital conversion module 10A receives a voltage sampling signal 01 obtained by external sampling. The first output end of the analog-to-digital conversion module 10A outputs a voltage conversion signal 03 to the first input end of the comparison module 11A. The second output end of the analog-to-digital conversion module 10A outputs a minimum voltage conversion signal 04 to the first input end of the analog-to-digital conversion module 10B. The third output end of the analog-to-digital conversion module 10A outputs a conversion number 02 to the first input end of the digital logic processing module 12. The second input end of the comparison module 11A receives a voltage sampling signal 01 obtained by external sampling. The output end of the comparison module 11A outputs a secondary voltage sampling signal 05 to the second input end of the analog-to-digital conversion module 10B. The analog-to-digital conversion module 10B outputs a conversion number 06 and a minimum voltage number 07 to the second input end of the digital logic processing module 12.

[0044] It is understandable that although Figure 1The working process of the analog-to-digital conversion device 1 includes two working logic parts: calculating the calibration coefficient of the analog-to-digital conversion module 10A to be calibrated and converting the voltage sampling signal 01 into a digital representation. In fact, the above two working logic parts can be performed independently of each other, and the workflow of calculating the calibration coefficient does not depend on the workflow of the analog-to-digital conversion. Therefore, the calibration coefficient of the analog-to-digital conversion module 10A to be calibrated can be calculated first, and then stored in the digital logic processing module 12. When executing the workflow of converting the voltage sampling signal 01 into a digital representation, the stored calibration coefficient can be directly obtained without the need to synchronously execute the workflow of calculating the calibration coefficient of the analog-to-digital conversion module 10A to be calibrated.

[0045] In order to facilitate the understanding of this solution, this manual will introduce the processing logic of these two parts separately:

[0046] like Figure 2 As shown, assuming that the calibration coefficient of the analog-to-digital conversion module 10A to be calibrated has been calculated in advance and saved in the digital logic processing module 12, the working process of the analog-to-digital conversion device 1 converting the sampled voltage sampling signal 01 into a digital representation can be as follows:

[0047] The analog-to-digital conversion module 10A receives the voltage sampling signal 01, and outputs the conversion number 02 corresponding to the voltage sampling signal 01 to the digital logic processing module 12, and outputs the voltage conversion signal 03 corresponding to the conversion number 02 to the comparison module 11A. It can be understood that the voltage sampling signal 01 is a discrete voltage signal obtained by sampling the input analog voltage signal, and the discrete voltage signal can be converted into a corresponding digital signal for representation by the analog-to-digital conversion module 10A. Of course, a follower can be set on the analog-to-digital conversion device 1 to receive the original voltage sampling signal, and the original voltage sampling signal is processed by the follower to obtain the voltage sampling signal 01. This specification does not limit the method of obtaining the voltage sampling signal 01.

[0048] The meaning of the conversion number output by any analog-to-digital conversion module involved in this specification can be the digital representation obtained by the analog-to-digital conversion module converting the input voltage signal. The meaning of the voltage conversion signal can be the analog voltage signal generated by the analog-to-digital conversion module to represent the voltage represented by the conversion number. For example, the meaning of the conversion number 02 in this solution can be the digital representation output by the analog-to-digital conversion module 10A for the voltage sampling signal 01. The voltage conversion signal 03 can be an analog voltage signal of the voltage represented by the conversion number 02 generated by the analog-to-digital conversion module 10A.

[0049] Exemplarily, taking the analog-to-digital conversion module as a successive approximation register analog-to-digital converter as an example, the successive approximation register analog-to-digital converter (or successive approximation type ADC) internally includes an analog-to-digital converter DAC and a SAR register. The DAC generates a corresponding voltage conversion signal according to the conversion number of the SAR register, and compares it with the voltage sampling signal. According to the comparison result, the conversion number in the SAR register is continuously adjusted to obtain the conversion number corresponding to the voltage sampling signal. For example, the value of the sampled voltage signal is 2.1V, the current conversion number in the SAR register is 001, and the voltage conversion signal output by the current corresponding DAC is 1V. Since 1V is less than 2V, the bit value of the conversion number of the SAR register is increased to 010, and the voltage conversion signal output by the DAC is increased to 2V. Since 2V is less than 2.1V, the bit value of the current conversion number of the SAR register is further adjusted to 011, and the voltage conversion signal output by the DAC is further increased to 3V. Since 3V is greater than 2.1V, the conversion number output by the SAR register can be 010, and the value of the voltage conversion signal corresponding to the conversion number output by the DAC is 2V.

[0050] The comparison module 11A receives the voltage sampling signal 01 and the voltage conversion signal 03 output by the analog-to-digital conversion module 10A, and outputs the difference between the voltage sampling signal 01 and the voltage conversion signal 03 as a secondary voltage sampling signal 05 to the analog-to-digital conversion module 10B. It can be understood that the difference between the voltage sampling signal 01 and the voltage conversion signal 03 is always within the LSB range of an error unit of the analog-to-digital conversion module 10A. By performing a difference operation, the secondary voltage sampling signal 05 within the error range that the analog-to-digital conversion module 10A cannot accurately process can be continuously output to the analog-to-digital conversion module 10B with a higher conversion accuracy for further processing. Similarly, the new secondary voltage sampling signal within the error range that the analog-to-digital conversion module 10B cannot accurately process can be continuously output to the next analog-to-digital conversion module for further processing. By analogy, the next analog-to-digital conversion module can also continue to output the new secondary voltage sampling signal within the error range that it cannot accurately process to the next analog-to-digital conversion module for further processing.

[0051] The LSB of the analog-to-digital conversion module 10B can be smaller than the LSB of the analog-to-digital conversion module 10A, so that the analog-to-digital conversion module 10B can more accurately process the secondary voltage sampling signal 05 that the analog-to-digital conversion module 10A cannot accurately convert. The analog-to-digital conversion module 10B outputs the conversion number 06 corresponding to the secondary voltage sampling signal 05 to the digital logic processing module 12.

[0052] The digital logic processing module 12 can determine the digital representation corresponding to the voltage sampling signal 01 based on the received conversion number 02 and conversion number 06, that is, conversion number 02*calibration coefficient+conversion number 06. Among them, the calibration coefficient can be the ratio of the actual value of the minimum voltage conversion signal generated by the analog-to-digital conversion module 10A measured by the analog-to-digital conversion module 10B to the theoretical value, which is used to improve the accuracy of the conversion number 02 determined based on the minimum voltage conversion signal. The specific calculation method of the calibration coefficient is not introduced in this embodiment, and please refer to the embodiment specifically introducing the calibration coefficient.

[0053] For example, it is assumed that the voltage of the voltage sampling signal 01 is 9.77V. The calibration coefficient of the analog-to-digital conversion module 10A stored in the digital logic processing module 12 is 1.11. The voltage range that the analog-to-digital conversion module 10A can process is [0, 10V], and the LSB is 1V. The voltage range that the analog-to-digital conversion module 10B can process is [0, 2V], and the LSB is 0.01V. The conversion number 02 output by the analog-to-digital conversion module 10A can be a digital representation of 9V, and the voltage conversion signal 03 corresponding to the generated conversion number 02 is output to the comparison module 11A. The comparison module 11A can output the difference 0.77V between the voltage sampling signal 01 of 9.77V and the voltage conversion signal 03 of the analog 9V as the secondary voltage sampling signal 05 to the analog-to-digital conversion module 10B. The conversion number 06 output by the analog-to-digital conversion module 10B can be a digital representation of 0.77V. Finally, the digital logic processing module 12 determines that the size of the digital representation corresponding to the voltage sampling signal 01 is 9V*1.11+0.77V.

[0054] In the above-mentioned example, the analog-to-digital conversion module 10A may be affected by factors such as external extreme temperature or component aging, which may cause the size of the voltage conversion signal 03 generated by the analog-to-digital conversion module 10A to be different from the size represented by the corresponding conversion number 02. For example, the conversion number 02 represents a voltage of 9V, and the voltage conversion signal 03 actually generated based on the conversion number 02 drifts, which may be 8.9V, 9.2V, etc., which is not the same as the 9V voltage represented by the conversion number 02. Therefore, the error size of the conversion number 02 determined after comparing the voltage conversion signal 03 with the voltage sampling signal 01 is within the LSB range of the analog-to-digital conversion module 10A, that is, within the 1V range. Therefore, if the conversion number 02 is not calibrated, even if the error range of the conversion number of the analog-to-digital conversion module 10B is within the 0.01V range, the digital representation after the combination of the two still cannot reach the accuracy of 0.01V, causing the error range of the digital representation corresponding to the voltage sampling signal 01 determined by the digital logic processing module 12 after combining the conversion numbers output by the two is still within the 1V range. The present solution further calibrates the conversion number 02 of the analog-to-digital conversion module 10A with an error range of 1V by using the analog-to-digital conversion module 10B with an error range of 0.01V, so that its error range is adjusted to 0.01V, and finally the total error range of the digital representation corresponding to the voltage sampling signal 01 is within 0.01V.

[0055] Assume that you want to design a single analog-to-digital converter with an LSB of 0.01V and a voltage range of [0, 11V], and the required resolution must reach 1100 levels. The LSB of the analog-to-digital conversion module 10A of the analog-to-digital conversion device 1 in this example is 1V, and the voltage range is [0, 10V], so its resolution is 10 levels. The LSB of the analog-to-digital conversion module 10B is 0.01, and the voltage range is [0, 2V], so its resolution is 200 levels. It can be understood that the analog-to-digital conversion device 1 uses a total of two analog-to-digital conversion modules with a total resolution of 210 levels to achieve the digital representation effect of a single analog-to-digital converter with a resolution of 1100 levels, and the accuracy of the digital representation after calibration also reaches the accuracy level of the single analog-to-digital converter.

[0056] Next, how to determine the calibration coefficient of the analog-to-digital conversion module 10A is described:

[0057] like Figure 3As shown, the analog-to-digital conversion module 10A outputs the minimum voltage conversion signal 04 representing its LSB size to the analog-to-digital conversion module 10B, and the analog-to-digital conversion module 10B outputs the minimum voltage number 07 corresponding to the minimum voltage conversion signal 04 to the digital logic processing module 12. The digital logic processing module 12 determines the calibration coefficient of the analog-to-digital conversion module 10A based on the LSB of the analog-to-digital conversion module 10A and the minimum voltage number 07. Exemplarily, the calibration coefficient may be the ratio of the minimum voltage number 07 to the LSB of the analog-to-digital conversion module 10A.

[0058] In an illustrated embodiment, optionally, the system may perform the following operations at predetermined intervals: Figure 3 The calibration coefficient of the analog-to-digital conversion module 10A is re-determined in the manner shown, and the calibration coefficient is updated and stored in the digital logic processing module 12. Optionally, the calibration coefficient of the analog-to-digital conversion module 10A can be determined each time the analog-to-digital conversion device 1 is started, and it is updated and stored in the digital logic processing module 12. This specification does not limit the timing of determining the calibration coefficient of the analog-to-digital conversion module 10A.

[0059] Next, we will continue to introduce the structure of an analog-to-digital conversion device that includes three or more analog-to-digital conversion modules:

[0060] like Figure 4 As shown, Figure 4 It is a structural schematic diagram of an analog-to-digital conversion device including three analog-to-digital conversion modules shown in an embodiment of this specification, and the analog-to-digital conversion device 2 includes a digital logic processing module 12, an analog-to-digital conversion module 10A, an analog-to-digital conversion module 10B, an analog-to-digital conversion module 10C, a comparison module 11A and a comparison module 11B. Each analog-to-digital conversion module is sequentially connected with each comparison module at intervals, and the least significant bit value LSB of the latter analog-to-digital conversion module is less than the LSB of the previous analog-to-digital conversion module. For example, the LSB of the analog-to-digital conversion module 10C is less than the LSB of the analog-to-digital conversion module 10B, and the LSB of the analog-to-digital conversion module 10B is less than the LSB of the analog-to-digital conversion module 10A.

[0061] Specifically, the input end of the analog-to-digital conversion module 10A receives the voltage sampling signal 01. The first output end of the analog-to-digital conversion module 10A outputs the conversion number 02A to the first input end of the digital logic processing module 12. The second output end of the analog-to-digital conversion module 10A outputs the minimum voltage conversion signal 04A to the first input end of the analog-to-digital conversion module 10B. The third output end of the analog-to-digital conversion module 10A outputs the voltage conversion signal 03A to the first input end of the comparison module 11A. The second input end of the comparison module 11A receives the voltage sampling signal 01. The first output end of the comparison module 11A outputs the secondary voltage sampling signal 05A to the second input end of the analog-to-digital conversion module 10B. The second output end of the comparison module 11A outputs the secondary voltage sampling signal 05A to the comparison module 11B. The first output end of the analog-to-digital conversion module 10B outputs the conversion number 02B and the minimum voltage number 07B to the second input end of the digital logic processing module 12. The second output terminal of the analog-to-digital conversion module 10B outputs the voltage conversion signal 03B to the second input terminal of the comparison module 11B. The third output terminal of the analog-to-digital conversion module 10B outputs the minimum voltage conversion signal 04B to the first input terminal of the analog-to-digital conversion module 10C. The comparison module 11B outputs the secondary voltage sampling signal 05B to the second input terminal of the analog-to-digital conversion module 10C. The output terminal of the analog-to-digital conversion module 10C outputs the conversion number 02C and the minimum voltage number 07C to the third input terminal of the digital logic processing module 12.

[0062] Similar to the introduction process of the analog-to-digital conversion device 1 described above, this specification will separately introduce the analog-to-digital conversion process and the calibration process of the analog-to-digital conversion device 2:

[0063] Since the LSB of the analog-to-digital conversion module of the latter stage is smaller than the LSB of the analog-to-digital conversion module of the former stage, the analog-to-digital conversion module of the latter stage can be used to calibrate the conversion numbers output by all the analog-to-digital conversion modules in front of it. For example, the analog-to-digital conversion module 10C can be used to calibrate the conversion number 02B output by the analog-to-digital conversion module 10B, and the analog-to-digital conversion module 10B and / or the analog-to-digital conversion module 10C can be used to calibrate the conversion number 02A output by the analog-to-digital conversion module 10A.

[0064] like Figure 5 As shown, assuming that the calibration coefficients of the analog-to-digital conversion module 10A and the analog-to-digital conversion module 10B to be calibrated have been calculated in advance and stored in the digital logic processing module 12, the working process of the analog-to-digital conversion device 2 converting the sampled voltage sampling signal 01 into a digital representation can be as follows:

[0065] The analog-to-digital conversion module 10A receives the sampled voltage sampling signal 01 and outputs the corresponding conversion number 02A to the digital logic processing module 12, and outputs the voltage conversion signal 03A corresponding to the conversion number 02A to the comparison module 11A. The comparison module 11A receives the sampled voltage sampling signal 01 and the voltage conversion signal 03A, and outputs the difference between the voltage sampling signal 01 and the voltage conversion signal 03A as the secondary voltage sampling signal 05A to the analog-to-digital conversion module 10B and the comparison module 11B. The analog-to-digital conversion module 10B outputs the conversion number 02B corresponding to the secondary voltage sampling signal 05A to the digital logic processing module 12, and outputs the voltage conversion signal 03B corresponding to the conversion number 02B to the comparison module 11B. The comparison module 11B outputs the difference between the secondary voltage sampling signal 05A and the voltage conversion signal 03B as the new secondary voltage sampling signal 05B to the analog-to-digital conversion module 10C. The analog-to-digital conversion module 10C outputs the conversion digital 02C corresponding to the secondary voltage sampling signal 05B to the digital logic processing module 12 .

[0066] The digital logic processing module 12 obtains the stored calibration coefficient corresponding to the analog-to-digital conversion module 10A, calibrates the conversion number 02A to obtain the calibrated conversion number 02A, obtains the calibration coefficient corresponding to the analog-to-digital conversion module 10B, calibrates the conversion number 02B to obtain the calibrated conversion number 02B, and then uses the sum of the calibrated conversion number 02A, the calibrated conversion number 02B and the conversion number 02C as the digital representation corresponding to the voltage sampling signal 01 received by the analog-to-digital conversion device 2.

[0067] For example, assuming that the voltage of the voltage sampling signal 01 is 9.77V, the calibration coefficient of the analog-to-digital conversion module 10A stored in the digital logic processing module 12 is 1.1, and the calibration coefficient of the analog-to-digital conversion module 10B is 1.2. The voltage range that the analog-to-digital conversion module 10A can process is [0, 10V], and the LSB is 1V. The voltage range that the analog-to-digital conversion module 10B can process is [0, 2V], and the LSB is 0.1V. The voltage range that the analog-to-digital conversion module 10C can process is [0, 0.2V], and the LSB is 0.01V. The conversion number 02A output by the analog-to-digital conversion module 10A is a digital representation of 9V, and the voltage conversion signal 03A represents an analog voltage signal of 9V. The comparison module 11A outputs the difference 0.77V between the received voltage sampling signal 01 of 9.77V and the voltage conversion signal 03A of 9V as the secondary voltage sampling signal 05A to the analog-to-digital conversion module 10B and the comparison module 11B respectively. The analog-to-digital conversion module 10B outputs the conversion number 02B corresponding to the secondary voltage sampling signal 05A of 0.77V to the digital logic processing module 12, and outputs the voltage conversion signal 03B representing the magnitude of 0.7V to the comparison module 11B. The comparison module 11B outputs the difference 0.07V between the received secondary voltage signal 05A of 0.77V and the conversion voltage signal 03B of 0.7V as a new secondary voltage sampling signal 05B to the analog-to-digital conversion module 10C. The analog-to-digital conversion module 10C outputs the generated conversion number 02C corresponding to the secondary voltage sampling signal 05B to the digital logic processing module 12. The digital logic processing module 12 can finally determine that the digital representation corresponding to the voltage sampling signal 01 is 9V*1.1+0.7V*1.2+0.07V.

[0068] Assuming that you want to design a single analog-to-digital converter with an LSB of 0.01V and a voltage range of [0, 11V], the required resolution must reach 1100 levels. The resolutions of the analog-to-digital conversion module 10A, the analog-to-digital conversion module 10B, and the analog-to-digital conversion module 10C of the analog-to-digital conversion device 2 in this example are 10 levels, 20 levels, and 20 levels, respectively. It can be understood that the analog-to-digital conversion device 2 uses a total of three analog-to-digital conversion modules with a total resolution of 50 levels to achieve the digital representation effect of a single analog-to-digital converter with a resolution of 1100 levels, and the accuracy after calibration reaches the accuracy level of the single analog-to-digital converter.

[0069] It should be noted that, as for the design structures of the aforementioned analog-to-digital conversion device 1 and the analog-to-digital conversion device 2, both meet the accuracy requirement of 0.01V, the number of analog-to-digital conversion modules of the analog-to-digital conversion device 2 is more than that of the analog-to-digital conversion device 1, but the total resolution of the analog-to-digital conversion device 2 is lower than the total resolution of the analog-to-digital conversion device 1. Therefore, those skilled in the art can determine the number and resolution requirements of the analog-to-digital conversion modules in the analog-to-digital conversion device according to actual application requirements, and this specification does not impose any restrictions on this.

[0070] Next, how to determine the calibration coefficients of the analog-to-digital conversion module 10A and the analog-to-digital conversion module 10B is described:

[0071] like Figure 6 As shown, the analog-to-digital conversion module 10A outputs the minimum voltage conversion signal 04A indicating its LSB size to the analog-to-digital conversion module 10B, and the analog-to-digital conversion module 10B outputs the minimum voltage number 07B corresponding to the minimum voltage conversion signal 04A to the digital logic processing module 12. The analog-to-digital conversion module 10B outputs the minimum voltage conversion signal 04B indicating its LSB size to the analog-to-digital conversion module 10C, and the analog-to-digital conversion module 10C outputs the minimum voltage number 07C corresponding to the minimum voltage conversion signal 04B to the digital logic processing module 12. The digital logic processing module 12 can determine the calibration coefficients of the analog-to-digital conversion module 10A and the analog-to-digital conversion module 10B based on the first LSB of the analog-to-digital conversion module 10A, the second LSB of the analog-to-digital conversion module 10B, the minimum voltage number 07B, and the minimum voltage number 07C.

[0072] In an illustrated embodiment, for each analog-to-digital conversion module except the first analog-to-digital conversion module, the ratio of the minimum voltage digital output by the module to the LSB of the previous analog-to-digital conversion module can be determined as the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module. For example, the ratio of the minimum voltage digital 07B output by the analog-to-digital conversion module 10B to the conversion digital 02A can be determined as the calibration coefficient of the analog-to-digital conversion module 10A. For example, the ratio of the minimum voltage digital 07C output by the analog-to-digital conversion module 10C to the conversion digital 02B can be determined as the calibration coefficient of the analog-to-digital conversion module 10A and the analog-to-digital conversion module 10B before it. For example, assuming that the ratio of the minimum voltage digital 07B to the first LSB is 1.1, and the ratio of the minimum voltage digital 07C to the second LSB is 1.2, then 1.1 and 1.2 can be used as the calibration coefficients of the analog-to-digital conversion module 10A, and 1.2 can be used as the calibration coefficient of the analog-to-digital conversion module 10B.

[0073] In an illustrated embodiment, the conversion number output by the analog-to-digital conversion module to be calibrated can be continuously multiplied with at least one calibration coefficient corresponding thereto to obtain the calibrated conversion number corresponding to the analog-to-digital conversion module. For example, the calibration coefficient 1.1 is obtained by calibrating the analog-to-digital conversion module 10A based on the analog-to-digital conversion module 10B, and the calibration coefficient 1.2 is obtained by calibrating the analog-to-digital conversion module 10B based on the analog-to-digital conversion module 10C. Therefore, the final calibration coefficient of the analog-to-digital conversion module 10B can be 1.1*1.2, and the final calibration coefficient can be multiplied with the conversion number 02A to obtain the calibrated conversion number 02A. Similarly, if the analog-to-digital conversion device also includes an analog-to-digital conversion module n and an analog-to-digital conversion module n-1, the calibration coefficient x is obtained by calibrating the analog-to-digital conversion module 10C based on the analog-to-digital conversion module n, and the calibration coefficient y is obtained by calibrating the analog-to-digital conversion module n-1 based on the analog-to-digital conversion module n. The final calibration coefficient of the analog-to-digital conversion module 10A may be 1.1*1.2*x*y; the final calibration coefficient of the analog-to-digital conversion module 10B is 1.2*x*y; the final calibration coefficient of the analog-to-digital conversion module 10C is x*y; and the final calibration coefficient of the analog-to-digital conversion module n-1 is y.

[0074] The above is only an exemplary introduction of an analog-to-digital conversion device 1 comprising two analog-to-digital conversion modules and an analog-to-digital conversion device 2 comprising three analog-to-digital conversion modules. It can be understood that a person skilled in the art can undoubtedly infer an analog-to-digital conversion device comprising n analog-to-digital conversion modules on this basis, where n is greater than or equal to 4.

[0075] In an illustrated embodiment, since other analog-to-digital conversion modules except the last analog-to-digital conversion module need to output voltage conversion signals, all analog-to-digital conversion modules or modules except the last analog-to-digital conversion module can be analog-to-digital converters with the function of outputting voltage conversion signals. For example, the DAC of a successive approximation register analog-to-digital converter has the function of outputting voltage conversion signals. Therefore, the type of the analog-to-digital converter can be a successive approximation register analog-to-digital converter.

[0076] In an embodiment shown, the comparison module in this solution is mainly used to perform a subtraction function, that is, to perform a subtraction operation on two received voltage signals, so a subtractor can be selected as the comparison module. Of course, a comparator other than a comparator with a subtraction function can also be selected as the comparison module, and this specification does not impose any restrictions on this.

[0077] In an illustrated embodiment, the maximum value of the reference voltage of each analog-to-digital conversion module except the first analog-to-digital conversion module is not less than twice the least significant bit value of the previous analog-to-digital conversion module, so as to ensure that the subsequent analog-to-digital conversion module can calibrate the error of the previous comparison module. Since the voltage range that the subsequent analog-to-digital conversion module can handle depends on the least significant bit value of the previous analog-to-digital conversion module, preferably, the maximum value of the reference voltage of each analog-to-digital conversion module except the first analog-to-digital conversion module can be set equal to twice the least significant bit value of the previous analog-to-digital conversion module.

[0078] like Figure 7 As shown, Figure 7 is a flow chart of a digital signal calibration method according to an exemplary embodiment of the present specification. The calibration method can be applied to Figure 1 or Figure 2 The digital logic processing module 12 comprises the following steps 701-703:

[0079] Step 701: Obtain the conversion digital and minimum voltage digital respectively input by each analog-to-digital conversion module.

[0080] Step 702: For each analog-to-digital conversion module except the first analog-to-digital conversion module, determine a calibration coefficient of a conversion number output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage number output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module.

[0081] Step 703: Calibrate the conversion numbers output by the at least one analog-to-digital conversion module based on the calibration coefficient to obtain calibrated conversion numbers, and determine the sum of all calibrated conversion numbers and uncalibrated conversion numbers as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

[0082] In this embodiment, by calibrating the conversion numbers output by the low-precision analog-to-digital conversion module based on the high-precision analog-to-digital conversion module, the error in the conversion numbers indirectly caused by the offset error of the voltage conversion signal generated by the low-precision analog-to-digital conversion module can be eliminated, thereby improving the accuracy of the conversion numbers output by the low-precision analog-to-digital conversion module, thereby improving the overall accuracy of the digital representation determined based on the conversion numbers output by each analog-to-digital conversion module.

[0083] Corresponding to the embodiments of the aforementioned method, this specification also provides embodiments of a device and a terminal to which it is applied.

[0084] like Figure 8 As shown, Figure 8It is a structural diagram of an electronic device 800 shown in this specification according to an exemplary embodiment. At the hardware level, the device includes a processor 802, an internal bus 804, a network interface 806, a memory 808 and a non-volatile memory 810, and of course may also include hardware required for other services. One or more embodiments of this specification can be implemented based on software, such as the processor 802 reading the corresponding computer program from the non-volatile memory 810 into the memory 808 and then running it. Of course, in addition to the software implementation, one or more embodiments of this specification do not exclude other implementations, such as logic devices or a combination of software and hardware, etc., that is, the execution subject of the following processing flow is not limited to each logic module, but can also be hardware or logic devices.

[0085] like Fig. 9 As shown, Fig. 9 This specification is a digital signal calibration device according to an exemplary embodiment, which can be applied to Figure 8 In the electronic device 800 shown in the figure, the technical solution of this specification is implemented. The device includes:

[0086] An acquisition module 902 is used to acquire conversion numbers and minimum voltage numbers respectively input by each analog-to-digital conversion module;

[0087] The calibration coefficient determination module 904 is used to determine, for each analog-to-digital conversion module except the first analog-to-digital conversion module, the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digital output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module;

[0088] The digital representation calibration module 906 is used to calibrate the conversion digital output by the at least one analog-to-digital conversion module based on the calibration coefficient to obtain a calibrated conversion digital, and determine the sum of all calibrated conversion digitals and uncalibrated conversion digitals as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

[0089] The implementation process of the functions and effects of each module in the above-mentioned device is specifically described in the implementation process of the corresponding steps in the above-mentioned method, which will not be repeated here.

[0090] For the device embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The device embodiment described above is only schematic, wherein the modules described as separate components may or may not be physically separated, and the components displayed as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this specification. Ordinary technicians in this field can understand and implement it without paying creative work.

[0091] The present specification also provides a computer-readable storage medium having a computer program stored thereon, and when the program is executed by a processor, the steps of the aforementioned digital signal calibration method provided in the present application are implemented.

[0092] Specifically, computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media and memory devices, including, for example, semiconductor memory devices (such as EPROM, EEPROM and flash memory devices), magnetic disks (such as internal hard disks or removable disks), magneto-optical disks, and CD ROM and DVD-ROM disks.

Claims

1. An analog-to-digital conversion device, characterized in that: The device comprises a digital logic processing module, a plurality of analog-to-digital conversion modules and at least one comparison module, wherein each analog-to-digital conversion module is sequentially connected to each comparison module at intervals and the least significant bit value LSB of the subsequent analog-to-digital conversion module is smaller than the LSB of the previous analog-to-digital conversion module, and each analog-to-digital conversion module is respectively connected to the digital logic processing module, wherein: The first analog-to-digital conversion module is used to receive a voltage sampling signal, and output a conversion number corresponding to the voltage sampling signal to the digital logic processing module, output a voltage conversion signal corresponding to the conversion number to the first comparison module, and output a minimum voltage conversion signal representing its LSB size to its next analog-to-digital conversion module; The first comparison module is used to receive the voltage sampling signal, and input the difference between the voltage sampling signal and the voltage conversion signal output by the first analog-to-digital conversion module as a secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module respectively; Each comparison module except the first comparison module is used to output the difference between the secondary voltage sampling signal output by the previous comparison module and the voltage conversion signal output by the previous analog-to-digital conversion module as a new secondary voltage sampling signal to the next analog-to-digital conversion module and the next comparison module of the comparison module; Each analog-to-digital conversion module except the first analog-to-digital conversion module is used to output the minimum voltage conversion signal output by the previous analog-to-digital conversion module and the secondary voltage sampling signal output by the previous comparison module to the digital logic processing module, output the voltage conversion signal corresponding to the conversion number to the next comparison module, and output the minimum voltage conversion signal representing its LSB size to the next analog-to-digital conversion module; The digital logic processing module is used to determine, based on the received conversion digits and minimum voltage digits, for each analog-to-digital conversion module except the first analog-to-digital conversion module, the calibration coefficient of the conversion digit output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digit output by the module and the LSB of the previous analog-to-digital conversion module; and, based on the calibration coefficient, calibrate the conversion digit output by the at least one analog-to-digital conversion module to obtain a calibrated conversion digit, and determine the sum of all calibrated conversion digits and uncalibrated conversion digits as the digital representation corresponding to the voltage sampling signal.

2. The device according to claim 1, characterized in that All analog-to-digital conversion modules or other analog-to-digital conversion modules except the last analog-to-digital conversion module are successive approximation register analog-to-digital converters.

3. The device according to claim 1, characterized in that The comparison module is a subtractor.

4. The device according to claim 1, characterized in that The maximum value of the reference voltage of each analog-to-digital conversion module except the first analog-to-digital conversion module is not less than twice the least significant bit value of the previous analog-to-digital conversion module.

5. The device according to claim 1, characterized in that The method of determining the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digital output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module comprises: The ratio of the minimum voltage digital output by the analog-to-digital conversion module to the LSB of the previous analog-to-digital conversion module is determined as the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module.

6. The device according to claim 5, characterized in that The step of calibrating the conversion digital output by the at least one analog-to-digital conversion module based on the calibration coefficient to obtain a calibrated conversion digital comprises: For each analog-to-digital conversion module of the at least one analog-to-digital conversion module, a conversion number output by the analog-to-digital conversion module is continuously multiplied with at least one calibration coefficient corresponding to the analog-to-digital conversion module to obtain a calibrated conversion number corresponding to the analog-to-digital conversion module.

7. A method for calibrating a digital signal, characterized in that: The method is applied to a digital logic processing module in an analog-to-digital conversion device according to any one of claims 1 to 6, and the method comprises: Obtain the conversion numbers and minimum voltage numbers respectively input by each analog-to-digital conversion module; For each analog-to-digital conversion module except the first analog-to-digital conversion module, determine the calibration coefficient of the conversion digital output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage digital output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module; The conversion numbers output by the at least one analog-to-digital conversion module are calibrated based on the calibration coefficient to obtain calibrated conversion numbers, and the sum of all calibrated conversion numbers and uncalibrated conversion numbers is determined as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

8. A digital signal calibration device, characterized in that: The device is applied to a digital logic processing module in an analog-to-digital conversion device according to any one of claims 1 to 6, and the device comprises: An acquisition module, used for acquiring conversion numbers and minimum voltage numbers respectively input by each analog-to-digital conversion module; A calibration coefficient determination module, for each analog-to-digital conversion module except the first analog-to-digital conversion module, determining a calibration coefficient of a conversion number output by at least one analog-to-digital conversion module before the analog-to-digital conversion module according to the minimum voltage number output by the analog-to-digital conversion module and the LSB of the previous analog-to-digital conversion module; A digital representation calibration module is used to calibrate the conversion digital output by the at least one analog-to-digital conversion module based on the calibration coefficient to obtain a calibrated conversion digital, and determine the sum of all calibrated conversion digitals and uncalibrated conversion digitals as the digital representation corresponding to the voltage sampling signal received by the analog-to-digital conversion device.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the steps of the method according to claim 7 are implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method according to claim 7 are implemented.

Images