Calibration Methods for Analog-to-Digital Converters

Abstract

The present invention provides a calibration method for an analog-to-digital converter, the method comprising the steps of: performing an initial performance test and judgment on the analog-to-digital converter; if the initial performance test of the analog-to-digital converter passes, pre-adjusting and judging the analog-to-digital converter; if the pre-adjustment of the analog-to-digital converter passes, performing error extraction on the analog-to-digital converter to obtain the errors of each conversion stage in the analog-to-digital converter; performing soft error correction and testing on the analog-to-digital converter based on the errors of each conversion stage; if the soft error correction test of the analog-to-digital converter passes, performing hard error correction and testing on the analog-to-digital converter based on the errors of each conversion stage. When performing error extraction on the analog-to-digital converter, the errors of each conversion stage in the analog-to-digital converter are extracted, thereby realizing multi-stage and multi-error extraction of the analog-to-digital converter; after confirming the adjustment effect through soft correction, hard correction is performed to solidify the error compensation information, thereby avoiding adjustment errors and improving the adjustment yield rate.

Description

Technical Field

[0001] The present invention relates to the technical field of integrated circuits, and in particular to a calibration method for an analog-to-digital converter. Background Art

[0002] An analog-to-digital converter is an electronic device that converts analog signals into digital signals. Its speed and accuracy determine the quality of signal acquisition and conversion. With the development of information technology, the requirements for signal acquisition and conversion are becoming increasingly higher. High-speed and high-precision analog-to-digital converters are a hot topic for the entire system. While advances in manufacturing processes have brought about speed increases, they have also led to more gain errors due to insufficient gain. This has reduced the accuracy of the analog-to-digital converter while increasing its speed, resulting in a decrease in its signal-to-noise ratio and linearity. To solve this problem, it is necessary to extract and calibrate errors in the multiple conversion stages with insufficient accuracy in the converter. Faced with these new problems, traditional error testing and calibration methods can no longer meet application requirements for testing and calibrating multiple stages and multiple errors in high-speed and high-precision converters under advanced process conditions:

[0003] (1) Traditional testing and error extraction methods can usually only extract the error of the first conversion stage, but cannot extract the errors of multiple conversion stages. They are not applicable to situations where errors exist in multiple conversion stages.

[0004] (2) Traditional error extraction methods usually only extract converter weight mismatch errors and are not applicable to gain error extraction caused by insufficient gain.

[0005] (3) The traditional error extraction method based on INL (integral nonlinear error) requires that the number of sample points collected increases exponentially as the converter accuracy improves, resulting in low test and calibration efficiency.

[0006] Therefore, there is an urgent need for a test and calibration solution for analog-to-digital converters to solve the problems that traditional error test and calibration methods cannot perform multi-level and multi-error calibration and have low test and calibration efficiency. Summary of the Invention

[0007] In view of the above-mentioned shortcomings of the prior art, the object of the present invention is to provide a calibration method for an analog-to-digital converter to solve the problems that traditional error test and calibration methods cannot perform multi-level and multi-error calibration and have low test and calibration efficiency.

[0008] To achieve the above-mentioned objectives and other related objectives, the present invention provides the following technical solutions.

[0009] A method for calibrating an analog-to-digital converter comprises the steps of:

[0010] Conduct initial performance testing and judgment of analog-to-digital converters;

[0011] If the initial performance test of the analog-to-digital converter passes, pre-adjusting and judging the analog-to-digital converter;

[0012] If the pre-adjustment of the analog-to-digital converter is passed, performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter;

[0013] performing error soft correction and testing on the analog-to-digital converter according to the errors of the conversion stages at each level;

[0014] If the error soft-correction test of the analog-to-digital converter passes, the analog-to-digital converter is subjected to error hard-correction and testing according to the errors of each conversion stage.

[0015] Optionally, before performing an initial performance test and judgment on the analog-to-digital converter, the calibration method of the analog-to-digital converter further includes:

[0016] An input signal is configured according to an input range of the analog-to-digital converter.

[0017] Optionally, the maximum value of the input signal is greater than the maximum comparator threshold in the analog-to-digital converter, and the minimum value of the input signal is less than the minimum comparator threshold in the analog-to-digital converter.

[0018] Optionally, the step of performing an initial performance test and judgment on the analog-to-digital converter includes:

[0019] Configure handshake signals;

[0020] Performing an initial performance test on the analog-to-digital converter and collecting initial test output data of the analog-to-digital converter;

[0021] Determining whether the initial test output data is normal;

[0022] If the initial test output data is normal, calculating characteristic parameters of the analog-to-digital converter according to the initial test output data;

[0023] Determining whether the characteristic parameter reaches a threshold;

[0024] If the characteristic parameter reaches the threshold, the initial performance test of the analog-to-digital converter passes.

[0025] Optionally, the analog-to-digital converter includes N conversion stages, and the step of pre-adjusting and judging the analog-to-digital converter includes:

[0026] Under the constraint of minimum mean square error, extract the weight error of the conversion level of the first M levels;

[0027] Under the constraint of minimum mean square error, extracting the gain error of the conversion stage of the first M stages;

[0028] calibrating the analog-to-digital converter based on the weight errors and gain errors of the first M conversion stages;

[0029] Performing a performance test on the calibrated analog-to-digital converter and collecting a test output of the analog-to-digital converter;

[0030] determining whether the pre-adjustment of the analog-to-digital converter has passed according to the test output of the analog-to-digital converter;

[0031] Wherein, N is an integer greater than or equal to 2, and M is an integer from 1 to N-1.

[0032] Optionally, the step of performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter includes:

[0033] For each conversion stage, configuring the input signal and output mode according to the error amount to be tested;

[0034] For each conversion stage, performing analog-to-digital conversion by the analog-to-digital converter according to the configured input signal and the output mode, collecting output data of the analog-to-digital converter and restoring the output data according to the characteristics of the input signal to obtain ideal output data;

[0035] For each of the conversion stages, an error of the conversion stage is extracted from the difference between the output data and the ideal output data using an adaptive parameter extraction method.

[0036] Optionally, the error includes a weight error, a gain error and a jitter error; for each level of the conversion stage, from the subsequent conversion stage to the previous conversion stage, the weight error and the gain error of each level of the conversion stage are extracted in sequence.

[0037] Optionally, for each conversion stage, there is no order requirement for extracting the jitter error, but the jitter error is extracted after the weight error and the gain error are extracted.

[0038] Optionally, when it is necessary to test and extract the weight error and the gain error, the amplitude of the input signal at each level and the threshold voltage of the comparator at each level are configured, and the output result of the comparator at each level is sent out; when it is necessary to test and extract the jitter error, a random code and the output codes of the corresponding required conversion levels are sent out.

[0039] Optionally, the step of performing error soft correction and testing on the analog-to-digital converter according to the errors of each conversion stage includes:

[0040] sending the errors of the conversion stages at each level into a temporary storage register of the analog-to-digital converter for storage;

[0041] Calibrate the analog-to-digital converter using the error stored in the temporary storage register to complete error soft correction of the analog-to-digital converter;

[0042] Performing an analog-to-digital conversion test on the analog-to-digital converter after the error soft-correction to obtain soft-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error soft-correction based on the soft-correction test output data;

[0043] Whether the error soft-correction of the analog-to-digital converter passes is determined based on characteristic parameters of the analog-to-digital converter after the error soft-correction.

[0044] Optionally, the step of performing hard error correction and testing on the analog-to-digital converter according to the errors of each conversion stage includes:

[0045] Writing the errors of each conversion stage stored in the temporary storage register into the internal fixed memory of the analog-to-digital converter for permanent storage;

[0046] Each time the power is turned on, the error stored in the internal fixed memory is automatically read, and the analog-to-digital converter is calibrated according to the error to complete the error hard correction of the analog-to-digital converter;

[0047] Performing an analog-to-digital conversion test on the analog-to-digital converter after the error hard-correction to obtain hard-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error hard-correction based on the hard-correction test output data;

[0048] Whether the error hard correction of the analog-to-digital converter is passed is determined according to characteristic parameters of the analog-to-digital converter after the error hard correction.

[0049] As described above, the calibration method of the analog-to-digital converter provided by the present invention has at least the following beneficial effects:

[0050] Through initial performance testing and judgment, circuits with too low initial performance due to process deviations can be eliminated, so as to avoid such circuits from continuing to enter the subsequent test and adjustment steps and failing to form qualified products, resulting in various wastes of resources, thereby improving the test screening efficiency; by adding a pre-adjustment step to make a rough estimate of the final adjustment performance, the feasibility of the adjustment is evaluated, and a second screening is formed, so as to avoid the waste of various resources caused by circuits with excessive deviations entering the subsequent test and adjustment steps and failing to form qualified products, thereby further improving the test screening efficiency; when performing error extraction on the analog-to-digital converter, the errors of each conversion stage in the analog-to-digital converter can be extracted, thereby realizing multi-stage and multi-error extraction of the analog-to-digital converter; the method of confirming the adjustment effect through soft adjustment and then performing hard adjustment to solidify the error compensation information avoids adjustment errors and improves the adjustment yield rate; the overall calibration method is a digital calibration method, which has higher error calibration accuracy than the analog calibration method. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Shown is a schematic diagram of the steps of the calibration method of the analog-to-digital converter in the present invention.

[0052] Figure 2 Shown is a flow chart of performing initial performance testing and judgment on an analog-to-digital converter in an optional embodiment of the present invention.

[0053] Figure 3 Shown is a flow chart of a calibration method for an analog-to-digital converter according to an optional embodiment of the present invention. DETAILED DESCRIPTION

[0054] As mentioned in the background technology section above, the inventors have discovered that with the development of high-speed and high-precision analog-to-digital converters, while advancements in manufacturing processes have brought about speed increases, they have also resulted in more gain errors due to insufficient gain. This results in a decrease in accuracy while the speed of the analog-to-digital converter increases, leading to a decrease in its signal-to-noise ratio and linearity. To address this issue, it is necessary to extract and calibrate errors in multiple conversion stages with insufficient accuracy in the converter. Faced with these new problems, traditional error testing and calibration methods can no longer meet application requirements for testing and calibrating multiple stages and multiple errors in high-speed, high-precision converters under advanced process conditions:

[0055] (1) Traditional testing and error extraction methods can usually only extract the error of the first conversion stage, but cannot extract the errors of multiple conversion stages. They are not applicable to situations where errors exist in multiple conversion stages.

[0056] (2) Traditional error extraction methods usually only extract converter weight mismatch errors and are not applicable to gain error extraction caused by insufficient gain.

[0057] (3) The traditional error extraction method based on INL (integral nonlinear error) requires that the number of sample points collected increases exponentially as the converter accuracy improves, resulting in low test and calibration efficiency.

[0058] Based on this, the present invention proposes a test and calibration scheme for analog-to-digital converters: before the formal test and calibration, an initial performance test step and a pre-adjustment step are added to eliminate circuits with too low initial performance due to process deviations, so as to avoid the waste of various resources caused by such circuits continuing to enter the subsequent test and adjustment steps but failing to form qualified products, thereby improving the test screening efficiency; according to the different requirements of various errors at each level for input and output, the input signal, comparator threshold voltage and output mode are flexibly configured to realize multi-level and multi-error extraction of the analog-to-digital converter; after confirming the adjustment effect through soft adjustment, hard adjustment is performed to solidify the error compensation information, so as to avoid adjustment errors and improve the adjustment yield; an adaptive parameter extraction method is used to extract errors, reduce the number of samples, thereby reducing the calculation amount of parameter extraction and improving the test and calibration efficiency.

[0059] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different viewpoints and applications without departing from the spirit of the present invention.

[0060] See also Figures 1 to 3 . It should be noted that the diagrams provided in this embodiment only illustrate the basic concept of the present invention in a schematic manner, so the diagrams only show the components related to the present invention rather than being drawn according to the number, shape and size of the components during actual implementation. During actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated. The structure, proportion, size, etc. shown in the diagrams attached to this specification are only used to match the content disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no technical significance. Any modification of the structure, change in the proportional relationship or adjustment of the size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0061] like Figure 1 As shown, the present invention provides a calibration method for an analog-to-digital converter, which includes the steps of:

[0062] S1. Perform initial performance test and judgment on the analog-to-digital converter;

[0063] S2. If the initial performance test of the analog-to-digital converter passes, pre-adjustment and judgment of the analog-to-digital converter are performed;

[0064] S3. If the pre-adjustment of the analog-to-digital converter passes, performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter;

[0065] S4. Perform error soft correction and testing on the analog-to-digital converter based on the errors of each conversion stage;

[0066] S5. If the error soft-correction test of the analog-to-digital converter passes, the analog-to-digital converter is subjected to hard error correction and testing based on the errors of each conversion stage.

[0067] In detail, such as Figure 1 As shown, before performing initial performance testing and judgment on the analog-to-digital converter, the calibration method of the analog-to-digital converter further includes the steps of:

[0068] S0. Configure the input signal according to the input range of the analog-to-digital converter.

[0069] More specifically, in step S0, the maximum value of the input signal is greater than the maximum comparator threshold in the analog-to-digital converter, and the minimum value of the input signal is less than the minimum comparator threshold in the analog-to-digital converter. For example, an input signal 1 dB less than the full amplitude is usually input.

[0070] In detail, such as Figure 2 As shown, in an optional embodiment of the present invention, step S1 of performing initial performance testing and judgment on the analog-to-digital converter further includes:

[0071] S11, configure handshake signal;

[0072] S12, performing an initial performance test on the analog-to-digital converter and collecting initial test output data of the analog-to-digital converter;

[0073] S13, judging whether the initial test output data is normal;

[0074] S14. If the initial test output data is normal, calculating characteristic parameters of the analog-to-digital converter based on the initial test output data;

[0075] S15, determining whether the characteristic parameter reaches a threshold;

[0076] S16: If the characteristic parameter reaches the threshold, the initial performance test of the analog-to-digital converter passes, and the process proceeds to the next step.

[0077] In more detail, Figure 2 As shown, step S1 of performing initial performance testing and judgment on the analog-to-digital converter further includes:

[0078] S17. If the initial test output data is abnormal, return to the handshake signal configuration stage and start over;

[0079] S18. If the number of times the initial test output data is collected reaches the threshold and the initial test output data is still abnormal, determine the error type, classify the error, report the error, and exit;

[0080] S19. If the characteristic parameter does not reach the threshold, determine the error type, classify the error, and exit.

[0081] Among them, the characteristic parameters at least include typical characteristic parameters, such as signal-to-noise ratio, signal-to-noise and distortion ratio, spurious-free dynamic range, etc., which are not limited here; if the initial performance test of the analog-to-digital converter fails, it will directly exit and no longer enter the subsequent steps.

[0082] In detail, the analog-to-digital converter includes N conversion stages. In step S2, the steps of pre-adjusting and judging the analog-to-digital converter further include:

[0083] S21. Extract the weight errors of the first M conversion levels under the constraint of minimum mean square error;

[0084] S22. extracting the gain errors of the first M conversion stages under the constraint of minimum mean square error;

[0085] S23, calibrating the analog-to-digital converter according to the weight error and gain error of the first M conversion stages;

[0086] S24, performing a performance test on the calibrated analog-to-digital converter and collecting a test output of the analog-to-digital converter;

[0087] S25, judging whether the pre-adjustment of the analog-to-digital converter has passed according to the test output of the analog-to-digital converter;

[0088] Wherein, N is an integer greater than or equal to 2, and M is an integer from 1 to N-1.

[0089] In more detail, in step S2, pre-adjustment is performed and a determination is made as to whether the performance after adjustment meets the requirements. If so, the process continues; otherwise, the process exits. To improve efficiency, under the constraint of minimum mean square error, jitter error is generally not extracted, and only the weight error and gain error of the first one or several stages of the multiple conversion stages are extracted.

[0090] In detail, in an optional embodiment of the present invention, as Figure 3 As shown, step S3 of performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter further includes:

[0091] S31. For each conversion stage, configure the input signal and output mode according to the error amount to be tested;

[0092] S32. For each conversion stage, perform analog-to-digital conversion using an analog-to-digital converter according to the configured input signal and output mode, collect output data of the analog-to-digital converter, and restore the output data according to the characteristics of the input signal to obtain ideal output data;

[0093] S33. For each conversion stage, extract the error of the conversion stage from the difference between the output data and the ideal output data using an adaptive parameter extraction method.

[0094] Among them, the error of each conversion level includes weight error, gain error and jitter error; according to the different requirements of various errors at each level for output, the output mode is flexibly configured, and different data is output under different test requirements, so that the output interface is shared when different error tests are performed, the number of interfaces is reduced, and the hardware overhead is reduced; for each conversion level, from the rear conversion level to the front conversion level, the weight error and gain error of each conversion level are extracted in turn. The test sequence is tested from the rear stage to the front stage in sequence. Since each level test requires the configuration of different inputs, it is necessary to return to step S31 after each test to reconfigure the output mode and the input signal until the test of all error quantities is completed. For each conversion level, there is no order requirement for the extraction of jitter error, but it needs to be extracted after the weight error and gain error are extracted.

[0095] More specifically, in step S3, when it is necessary to test and extract weight error and gain error, the amplitude of the input signal at each stage and the threshold voltage of the comparator at each stage are configured, and the output result of the comparator at each stage is sent out; when it is necessary to test and extract jitter error, a random code and the output codes of the corresponding required conversion stages are sent out.

[0096] In detail, in an optional embodiment of the present invention, as Figure 3 As shown, step S4 of performing soft error correction and testing on the analog-to-digital converter according to the errors of each conversion stage further includes:

[0097] S41, sending the errors of each conversion stage into a temporary storage register of the analog-to-digital converter for storage;

[0098] S42, calibrating the analog-to-digital converter using the error stored in the temporary storage register to complete soft error correction of the analog-to-digital converter;

[0099] S43, performing an analog-to-digital conversion test on the analog-to-digital converter after the error soft-correction, obtaining soft-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error soft-correction based on the soft-correction test output data;

[0100] S44. Determine whether the error soft-correction of the analog-to-digital converter has passed according to the characteristic parameters of the analog-to-digital converter after the error soft-correction.

[0101] Among them, error soft correction is to send the calculated error into the corresponding temporary storage register of the analog-to-digital converter through the interface, so as to temporarily compensate for the errors of each level obtained through the test; when testing the performance in the soft correction state, the input signal amplitude needs to be restored to close to the full amplitude, and the typical characteristic parameters after soft correction (such as signal-to-noise ratio, signal-to-noise and distortion ratio, spurious-free dynamic range, etc.) are tested, and then it is judged whether the performance after soft correction meets the requirements. If it does not meet the requirements, it returns to the pre-adjustment step for re-adjustment. If it fails and the number of adjustments reaches the threshold, the error type is judged and classified and reported, and then exits.

[0102] In detail, in an optional embodiment of the present invention, as Figure 3 As shown, step S5 of performing hard error correction and testing on the analog-to-digital converter according to the errors of each conversion stage further includes:

[0103] S51, writing the errors of each conversion stage stored in the temporary storage register into the internal fixed memory of the analog-to-digital converter for permanent storage;

[0104] S52, each time the power is turned on, the error stored in the internal fixed memory is automatically read, and the analog-to-digital converter is calibrated based on the error, completing the hard correction of the error of the analog-to-digital converter;

[0105] S53, performing an analog-to-digital conversion test on the analog-to-digital converter after the error hard-correction, obtaining hard-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error hard-correction based on the hard-correction test output data;

[0106] S54 , judging whether the error hard correction of the analog-to-digital converter is passed according to the characteristic parameters of the analog-to-digital converter after the error hard correction.

[0107] Among them, the error hard repair will save the error value in the temporary storage register and write it into the internal solidified memory for permanent storage. Each time the power is turned on, the internal solidified register value is automatically read to compensate for various errors of the converter. When the performance test is performed after the hard repair, the power is turned on again and the internal solidified register value is automatically read to compensate for various errors of the analog-to-digital converter. At this time, the input signal amplitude needs to be configured to be close to the full amplitude, and the typical characteristic parameters after the hard repair (such as signal-to-noise ratio, signal-to-noise and distortion ratio, spurious-free dynamic range, etc.) are tested. Then, it is judged whether the performance after the hard repair meets the requirements. If it passes, it will be displayed as completed. If it fails, the error type is judged and classified and reported, and then the program exits.

[0108] In summary, the calibration method of the analog-to-digital converter provided by the present invention can eliminate circuits with too low initial performance due to process deviations through initial performance testing and judgment, and avoid the waste of various resources caused by such circuits continuing to enter the subsequent test and adjustment steps but failing to form qualified products, thereby improving the test screening efficiency; by adding a pre-adjustment step to make a rough estimate of the final adjustment performance, the feasibility of the adjustment is evaluated, and a second screening is formed, thereby avoiding the waste of various resources caused by circuits with too large deviations entering the subsequent test and adjustment steps but failing to form qualified products, thereby further improving the test screening efficiency; according to the different requirements of various errors at various levels for input and output, the input signal, comparator threshold voltage and output Mode configuration, thus realizing multi-level and multi-error extraction of analog-to-digital converters; according to the different requirements of various errors at each level for input and output, the output mode configuration is flexibly performed, and different data is output under different test requirements, so that the output interface is shared when different error tests are performed, which reduces the number of interfaces and reduces hardware overhead; the method of confirming the adjustment effect through soft adjustment and then performing hard adjustment to solidify the error compensation information avoids adjustment errors and improves the adjustment yield rate; the use of adaptive parameter extraction method requires a small number of samples, which can greatly reduce the calculation amount of parameter extraction and improve the efficiency of testing and calibration; the overall calibration method is digital calibration, which has higher error calibration accuracy than the analog calibration method.

[0109] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A calibration method for an analog-to-digital converter, characterized in that: Including steps: Conduct initial performance testing and judgment of analog-to-digital converters; If the initial performance test of the analog-to-digital converter passes, pre-adjusting and judging the analog-to-digital converter; If the pre-adjustment of the analog-to-digital converter is passed, performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter; performing error soft correction and testing on the analog-to-digital converter according to the errors of the conversion stages at each level; If the error soft-correction test of the analog-to-digital converter passes, performing hard error correction and testing on the analog-to-digital converter according to the errors of each conversion stage; The analog-to-digital converter includes N conversion stages, and the pre-adjusting of the analog-to-digital converter includes: Under the constraint of minimum mean square error, extract the weight error of the conversion level of the first M levels; Under the constraint of minimum mean square error, extracting the gain error of the conversion stage of the first M stages; calibrating the analog-to-digital converter based on the weight errors and gain errors of the first M conversion stages; Wherein, N is an integer greater than or equal to 2, and M is an integer from 1 to N-1; The step of performing error extraction on the analog-to-digital converter to obtain errors of each conversion stage in the analog-to-digital converter includes: For each conversion stage, configuring the input signal and output mode according to the error amount to be tested; For each conversion stage, performing analog-to-digital conversion by the analog-to-digital converter according to the configured input signal and the output mode, collecting output data of the analog-to-digital converter and restoring the output data according to the characteristics of the input signal to obtain ideal output data; For each of the conversion stages, extracting an error of the conversion stage from a difference between the output data and the ideal output data using an adaptive parameter extraction method; The step of performing error soft correction and testing on the analog-to-digital converter according to the errors of each conversion stage includes: sending the errors of the conversion stages at each level into a temporary storage register of the analog-to-digital converter for storage; Calibrate the analog-to-digital converter using the error stored in the temporary storage register to complete error soft correction of the analog-to-digital converter; Performing an analog-to-digital conversion test on the analog-to-digital converter after the error soft-correction to obtain soft-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error soft-correction based on the soft-correction test output data; Whether the error soft-correction of the analog-to-digital converter passes is determined based on characteristic parameters of the analog-to-digital converter after the error soft-correction.

2. The calibration method of the analog-to-digital converter according to claim 1, wherein: Before performing an initial performance test and judgment on the analog-to-digital converter, the calibration method of the analog-to-digital converter further includes: An input signal is configured according to an input range of the analog-to-digital converter.

3. The calibration method of the analog-to-digital converter according to claim 2, wherein: The maximum value of the input signal is greater than the maximum comparator threshold in the analog-to-digital converter, and the minimum value of the input signal is less than the minimum comparator threshold in the analog-to-digital converter.

4. The calibration method of the analog-to-digital converter according to claim 1, wherein: The steps of performing initial performance testing and judgment on the analog-to-digital converter include: Configure handshake signals; Performing an initial performance test on the analog-to-digital converter and collecting initial test output data of the analog-to-digital converter; Determining whether the initial test output data is normal; If the initial test output data is normal, calculating characteristic parameters of the analog-to-digital converter according to the initial test output data; Determining whether the characteristic parameter reaches a threshold; If the characteristic parameter reaches the threshold, the initial performance test of the analog-to-digital converter passes.

5. The calibration method of the analog-to-digital converter according to claim 4, wherein: The step of judging the analog-to-digital converter includes: Performing a performance test on the calibrated analog-to-digital converter and collecting a test output of the analog-to-digital converter; According to the test output of the analog-to-digital converter, it is determined whether the pre-adjustment of the analog-to-digital converter has passed.

6. The method for calibrating an analog-to-digital converter according to claim 1, wherein: The errors include weight error, gain error and jitter error; for each level of the conversion stage, from the subsequent conversion stage to the previous conversion stage, the weight error and the gain error of each level of the conversion stage are extracted in sequence.

7. The calibration method of the analog-to-digital converter according to claim 6, characterized in that: For each level of the conversion stage, there is no order requirement for extracting the jitter error, but the jitter error is extracted after the weight error and the gain error are extracted.

8. The method for calibrating an analog-to-digital converter according to claim 6, wherein: When it is necessary to test and extract the weight error and the gain error, the amplitude of the input signal at each stage and the threshold voltage of the comparator at each stage are configured, and the output result of the comparator at each stage is sent out; When it is necessary to test and extract the jitter error, a random code and the output codes of the corresponding required conversion stages are sent out.

9. The method for calibrating an analog-to-digital converter according to claim 1, wherein: The step of performing hard error correction and testing on the analog-to-digital converter according to the errors of each conversion stage includes: Writing the errors of each conversion stage stored in the temporary storage register into the internal fixed memory of the analog-to-digital converter for permanent storage; Each time the power is turned on, the error stored in the internal fixed memory is automatically read, and the analog-to-digital converter is calibrated according to the error to complete the error hard correction of the analog-to-digital converter; Performing an analog-to-digital conversion test on the analog-to-digital converter after the error hard-correction to obtain hard-correction test output data, and calculating characteristic parameters of the analog-to-digital converter after the error hard-correction based on the hard-correction test output data; Whether the error hard correction of the analog-to-digital converter is passed is determined according to characteristic parameters of the analog-to-digital converter after the error hard correction.

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