ADC error correction method, system and error correction device

Abstract

An ADC error adjustment method, system and error adjustment device, the ADC error adjustment method, comprising the following steps: obtaining adjustment data, the adjustment data including M different pre-selected adjustment parameter groups, each pre-selected adjustment parameter group including a gain error adjustment value and an offset error adjustment value; sequentially adjusting the sampling results of N voltage points based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results; calculating M error parameter groups based on the M groups of adjustment results in a one-to-one correspondence; determining an adjustment final value parameter group from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups, the adjustment final value parameter group including a gain adjustment final value and an offset adjustment final value; adjusting the ADC gain error and offset error according to the adjustment final value parameter group. The above-mentioned ADC error adjustment method solves the problem of low adjustment accuracy of the gain error and offset error of the ADC transfer characteristic curve.

Description

Technical Field

[0001] The present invention belongs to the field of electronic technology, and in particular relates to an ADC error adjustment method, system and error adjustment device. Background Art

[0002] During the chip testing process and after production, due to the interference of non-ideal factors, the ADC output may have linearity and noise problems, resulting in the actual transfer characteristic curve of the ADC not being a straight line and being jittery. Therefore, these non-ideal factors need to be eliminated or avoided as much as possible.

[0003] Common A / D converters mainly have gain error and offset error. At present, it is generally recognized in the industry that the ADC transfer characteristic curve equation is defined as y=m in an ideal situation. i x, in actual situations, the ADC transfer characteristic curve equation is defined as y = m a x+b, m is the actual gain, b is the offset error. Gain error refers to the degree of deviation between the actual ADC transfer characteristic curve and the ideal transfer characteristic curve, while offset error refers to the steady-state offset in the ADC measurement output result caused by the input signal path and the reference signal path not being exactly the same.

[0004] The most commonly used adjustment method is the two-point calibration method: Assuming that the ADC transfer characteristic is a straight line, take the input low point (x1, y1) and high point (x2, y2), then the gain is m a =(y2–y1) / (x2-x1), offset b = ym a x, but for an actual ADC, the transfer characteristic curve is not a straight line, and the ADC output and input are not in a linear relationship. Therefore, the two-point calibration method cannot guarantee the accuracy of gain calculation near the lowest point and the highest point, and the calculated gain error and offset error have low accuracy. Summary of the invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an ADC error adjustment method, which solves the problem of low adjustment accuracy of gain error and offset error of ADC transfer characteristic curve.

[0006] The invention also provides an ADC error adjustment system and an error adjustment device.

[0007] According to the first aspect of the present invention, the ADC error adjustment method comprises the following steps:

[0008] Acquire trimming data, the trimming data comprising M different pre-selected trimming parameter groups, each of the pre-selected trimming parameter groups comprising a gain error trimming value and an offset error trimming value;

[0009] Sequentially adjusting the sampling results of the N voltage points based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results including N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range;

[0010] Based on the M groups of adjustment results, M error parameter groups are calculated one by one, each of which includes a gain error value and an offset error value;

[0011] Determine a final adjustment parameter group from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups, wherein the final adjustment parameter group includes a gain adjustment final value and an offset adjustment final value;

[0012] The ADC gain error and offset error are trimmed according to the trimming final value parameter group.

[0013] The ADC error adjustment method according to the embodiment of the present invention has at least the following technical effects: M different pre-selected adjustment parameter groups are obtained, each of which includes a gain error adjustment value and an offset error adjustment value; the sampling results of N voltage points are adjusted in turn based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results; M error parameter groups are calculated based on the M groups of adjustment results in a one-to-one correspondence, each of which includes a gain error value and an offset error value; a final adjustment parameter group is determined from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups; the gain adjustment final value and the offset adjustment final value in the final adjustment parameter group obtained have high accuracy, so that the ADC gain error and the offset error can be adjusted with high accuracy according to the gain adjustment final value and the offset adjustment final value to improve the accuracy of the ADC output signal, thereby solving the problem of low adjustment accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0014] According to some embodiments of the present invention, the gain error value and the offset error value in each error parameter group are obtained by the following steps:

[0015] Performing linear fitting according to the N trimming voltage signals in each group of the trimming results to obtain a fitting straight line;

[0016] The gain error value and the offset error value are calculated according to the fitting straight line.

[0017] According to some embodiments of the present invention, the calculation formula of the gain error value is:

[0018] GainError=|1-(N*Sum[2]-Sum[0]*Sum[1]) / SumTemp|

[0019] The calculation formula of the offset error value is:

[0020] OffsetError=|1-(Sum[1]*Sum[3]-Sum[0]*Sum[2]) / SumTemp|

[0021] In the formula, SumTemp=N*Sum[3]-Sum[0]*Sum[0];

[0022] Among them, x i is the input voltage signal of the preset fitting straight line, y i is the trimming voltage signal, and N is the number of the selected voltage points.

[0023] According to some embodiments of the present invention, the gain adjustment final value is obtained by the following steps:

[0024] Determining a minimum gain error value among the M gain error values;

[0025] Determining the preselected trimming parameter set corresponding to the minimum gain error value as a valid trimming parameter set;

[0026] The gain error trimming value in the valid trimming parameter group is determined as the gain trimming final value.

[0027] According to some embodiments of the present invention, the N voltage points are evenly distributed within the ADC sampling range.

[0028] According to some embodiments of the present invention, the sampling result of each voltage point is obtained by the following steps:

[0029] After sampling each voltage point multiple times continuously, an average value is calculated to obtain the sampling result.

[0030] An ADC error adjustment system according to an embodiment of the second aspect of the present invention includes:

[0031] A trimming data acquisition unit, used to acquire trimming data, wherein the trimming data includes M different pre-selected trimming parameter groups, each of which includes a gain error trimming value and an offset error trimming value;

[0032] A sampling voltage adjustment unit, used for adjusting the sampling results of N voltage points based on the M pre-selected adjustment parameter groups in sequence, so as to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results including N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range;

[0033] An error parameter calculation unit, used for calculating M error parameter groups based on the M groups of adjustment results, each of which includes a gain error value and an offset error value;

[0034] A final adjustment parameter determination unit, configured to determine a final adjustment parameter group from M different pre-selected adjustment parameter groups according to an ideal ADC transfer function and the M error parameter groups, wherein the final adjustment parameter group includes a gain adjustment final value and an offset adjustment final value;

[0035] The error adjustment unit is used to adjust the ADC gain error and offset error according to the adjustment final value parameter group.

[0036] The ADC error adjustment system according to the embodiment of the present invention has at least the following technical effects: M different pre-selected adjustment parameter groups can be obtained through the adjustment data acquisition unit, each of which includes a gain error adjustment value and an offset error adjustment value; the sampling results of N voltage points are adjusted in turn based on the M pre-selected adjustment parameter groups by the sampling voltage adjustment unit, and M groups of adjustment results can be obtained; the error parameter calculation unit calculates one by one based on the M groups of adjustment results, and M error parameter groups can be obtained, each of which includes a gain error value and an offset error value. The difference is finally determined by the final adjustment parameter determination unit, which can determine the final adjustment parameter group from M different pre-selected adjustment parameter groups according to the ideal transfer function of the ADC and the M error parameter groups. The gain adjustment final value and the offset adjustment final value in the final adjustment parameter group obtained have high accuracy. Therefore, the error adjustment unit can be used to perform high-precision adjustment on the ADC gain error and offset error according to the gain adjustment final value and the offset adjustment final value, so as to improve the accuracy of the ADC output signal and solve the problem of low adjustment accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0037] The error correction device according to the third aspect of the present invention includes:

[0038] An integrated circuit automatic tester for providing N voltage points;

[0039] An ADC unit, used for sampling the N voltage points;

[0040] A register for storing trimming data, a gain trimming final value, and an offset trimming final value; the trimming data includes M different pre-selected trimming parameter groups, each of which includes a gain error trimming value and an offset error trimming value;

[0041] A main control module is used to sequentially adjust the sampling results of the N voltage points based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results includes N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range; based on the M groups of adjustment results, M error parameter groups are calculated one-to-one, each error parameter group includes a gain error value and an offset error value; according to the ADC ideal transfer function and the M error parameter groups, a final adjustment parameter group is determined from the M different pre-selected adjustment parameter groups, the final adjustment parameter group includes the gain adjustment final value and the offset adjustment final value; and the ADC gain error and offset error are adjusted according to the final adjustment parameter group.

[0042] The error adjustment device according to the embodiment of the present invention has at least the following technical effects: N voltage points can be provided by an integrated circuit automatic test machine, and the N voltage points can be sampled by an ADC unit to obtain sampling results of the N voltage points, and adjustment data are stored in a register, and the adjustment data includes M different pre-selected adjustment parameter groups, each of which includes a gain error adjustment value and an offset error adjustment value, and the M different pre-selected adjustment parameter groups are obtained by a main control module, and the sampling results of the N voltage points are adjusted based on the M pre-selected adjustment parameter groups in turn, so that M groups of adjustment results can be obtained, and based on the M groups The trimming results are calculated one by one to obtain M error parameter groups, each error parameter group includes a gain error value and an offset error value, and a trimming final value parameter group is determined from M different pre-selected trimming parameter groups according to the ADC ideal transfer function and the M error parameter groups, and the gain trimming final value and the offset trimming final value in the obtained trimming final value parameter group have high accuracy, so that the ADC gain error and offset error can be trimmed with high accuracy according to the gain trimming final value and the offset trimming final value to improve the accuracy of the ADC output signal, thereby solving the problem of low trimming accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0043] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The above or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0045] Figure 1 is a flow chart of an ADC error correction method according to an embodiment of the present invention;

[0046] Figure 2 It is a schematic diagram of the actual transfer function of ADC and the ideal transfer function of ADC;

[0047] Figure 3 is a structural block diagram of an ADC error correction system according to an embodiment of the present invention;

[0048] Figure 4 It is a structural block diagram of an error correction device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0050] In the description of the present invention, it should be understood that descriptions involving orientations, such as up, down, front, back, left, right, etc., are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0051] In the description of the present invention, "several" means one or more, "more" means more than two, "greater than", "less than", "exceed" etc. are understood as not including the number itself, and "above", "below", "within" etc. are understood as including the number itself. If there is a description of "first" or "second", it is only used for the purpose of distinguishing the technical features, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0052] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0053] Reference below Figures 1 to 4 The ADC error adjustment method according to the first embodiment of the present invention is described.

[0054] The ADC error adjustment method according to an embodiment of the present invention comprises the following steps:

[0055] Acquire trimming data, the trimming data including M different pre-selected trimming parameter groups, each pre-selected trimming parameter group including a gain error trimming value and an offset error trimming value;

[0056] The sampling results of the N voltage points are sequentially adjusted based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results including N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range;

[0057] Based on the M groups of adjustment results, M error parameter groups are calculated one by one, each error parameter group including a gain error value and an offset error value;

[0058] According to the ADC ideal transfer function and the M error parameter groups, determining a final adjustment parameter group from the M different pre-selected adjustment parameter groups, the final adjustment parameter group including a gain adjustment final value and an offset adjustment final value;

[0059] The ADC gain error and offset error are trimmed according to the trimming final value parameter group.

[0060] First, it should be noted that in the embodiment of the present invention, the ADC sampling range is 0 to 3V, and the N voltage points are all within the range of 0 to 3V, but the ADC sampling range is determined by the ADC itself, and its specific value cannot be regarded as a limitation of the present invention. In addition, the gain error adjustment value and the offset error adjustment value are both natural numbers, but this cannot be regarded as a limitation of the present invention. In some embodiments, the gain error adjustment value and the offset error adjustment value can also be accurate to decimal points and can be preset according to the actual ADC situation. The value of M also needs to be preset according to the actual adjustment range of the gain error adjustment value and the offset error adjustment value.

[0061] The adjustment data includes M different pre-selected adjustment parameter groups, each of which includes a gain error adjustment value and an offset error adjustment value. Each pre-selected adjustment parameter group is a preset set of accurate values. Specifically, the value range of the gain error adjustment value and the offset error adjustment value is 0 to K-1, where K is an integer. The constraint formula for adjusting the sampling results of N voltage points based on the M pre-selected adjustment parameter groups in sequence is: i =Y+d, where y i The trimmed voltage signal is the trimmed voltage signal after trimming the sampled voltage signal, Y is the input voltage value of N voltage points, c is the gain, d is the offset, and M groups of trimming results can be obtained after trimming, and each group of trimming results includes N trimming voltage signals. Each group of trimming results can be calculated to obtain an error parameter group, and each error parameter group includes a gain error value and an offset error value.

[0062] like Figure 2As shown, the dotted line represents the actual transfer function of the ADC, the dotted line represents the ideal transfer function of the ADC, the ActualGain represents the actual gain of the actual transfer function of the ADC, the Ideal Gain represents the ideal gain of the ideal transfer function of the ADC, and the Actual offset represents the offset error of the actual transfer function of the ADC. The gain error refers to the degree of deviation between the actual transfer function of the ADC and the ideal transfer function of the ADC, and the offset error is the steady-state offset caused in the ADC measurement output result due to the fact that the input signal path and the reference signal path are not completely the same. According to the M error parameter groups and the ideal gain of the ideal transfer function of the ADC, the error parameter group of the actual transfer function of the ADC closest to the ideal transfer function of the ADC can be obtained, so that the final adjustment parameter group corresponding to the error parameter group closest to the ideal transfer function of the ADC can be determined from the M different pre-selected adjustment parameter groups. The accuracy of the gain adjustment final value and the offset adjustment final value in the adjustment final value parameter group is high, so that the ADC gain error and offset error can be adjusted with high precision according to the gain adjustment final value and the offset adjustment final value to improve the accuracy of the ADC output signal.

[0063] According to the ADC error adjustment method of the embodiment of the present invention, M different pre-selected adjustment parameter groups are obtained, each of which includes a gain error adjustment value and an offset error adjustment value. The sampling results of N voltage points are adjusted in turn based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results. M error parameter groups are calculated based on the M groups of adjustment results in a one-to-one correspondence, each of which includes a gain error value and an offset error value. According to the ADC ideal transfer function and the M error parameter groups, a final adjustment parameter group is determined from the M different pre-selected adjustment parameter groups. The gain adjustment final value and the offset adjustment final value in the final adjustment parameter group obtained have high accuracy, so that the ADC gain error and the offset error can be adjusted with high accuracy according to the gain adjustment final value and the offset adjustment final value to improve the accuracy of the ADC output signal, thereby solving the problem of low adjustment accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0064] In some embodiments of the present invention, the gain error value and the offset error value in each error parameter group are obtained by the following steps:

[0065] Performing linear fitting according to the N trimming voltage signals in each group of trimming results to obtain a fitting straight line;

[0066] The gain error value and the offset error value are calculated based on the fitting straight line.

[0067] According to the least square method, a linear fit is performed on the N trimming voltage signals in each set of trimming results to obtain a fitting straight line p(x)=bx+a, and its mean square error is:

[0068]

[0069] According to calculus theory, the minimum value of Q(a,b) must satisfy:

[0070]

[0071]

[0072] Arranged into matrix form (normal equation of the fitted line):

[0073]

[0074] Among them, x i is the input voltage signal of the preset fitting straight line, y i is the trimmed voltage signal, and N is the number of selected voltage points. m is determined by the number of ADC channels. For N trimmed voltage signals, m is equal to N, and the gain error value is calculated as:

[0075] GainError=|1-(N*Sum[2]-Sum[0]*Sum[1]) / SumTemp|

[0076] The offset error value is calculated as:

[0077] OffsetError=|1-(Sum[1]*Sum[3]-Sum[0]*Sum[2]) / SumTemp|

[0078] In the formula, SumTemp=N*Sum[3]-Sum[0]*Sum[0];

[0079] The definitions of Sum[0], Sum[1], Sum[2], Sum[3], and SumTemp are all obtained based on the normal equation of the fitted straight line. The gain error value and the offset error value of the fitted straight line for the N trimming voltage signals can be calculated through the constraint formula of the gain error value and the constraint formula of the offset error value. The gain error value and the offset error value form an error parameter group, which is convenient for determining the final trimming parameter group from M different pre-selected trimming parameter groups based on the ADC ideal transfer function and the M error parameter groups.

[0080] It should be noted that the principle of linear fitting is a prior art known to those skilled in the art and will not be elaborated here. In addition, linear fitting based on the least squares method is one of the common practices in the prior art, and other methods can also be used to perform linear fitting, which cannot be regarded as a limitation of the present invention. In an embodiment of the present invention, the number of ADC channels is 8, that is, the value of N is 8, but different ADC units have different numbers of channels, and the value of N cannot be regarded as a limitation of the present invention.

[0081] In some embodiments of the present invention, reference Figure 2 , the final value of gain adjustment is obtained by the following steps:

[0082] Determining a minimum gain error value among the M gain error values;

[0083] Determining a preselected trimming parameter group corresponding to the minimum gain error value as a valid trimming parameter group;

[0084] The gain error trim value in the valid trim parameter group is determined as the gain trim final value.

[0085] like Figure 2 As shown, Actual Gain represents the actual gain of the actual transfer function of ADC, Ideal Gain represents the ideal gain of the ideal transfer function of ADC, and Actual offset represents the offset error of the actual transfer function of ADC. The closer the actual gain of the actual transfer function of ADC is to the ideal gain of the ideal transfer function of ADC, the more accurate the corresponding pre-selected adjustment parameter group is, that is, the pre-selected adjustment parameter group corresponding to the minimum gain error value is the most accurate, which can be determined as the effective adjustment parameter group, and the gain error adjustment value in the effective adjustment parameter group is the gain adjustment final value. It should be noted that the offset adjustment final value in the effective adjustment parameter group is closer to 0 than the offset error adjustment values ​​in other pre-selected adjustment parameter groups. The specific determination process refers to the determination process of the gain adjustment final value, which will not be repeated here.

[0086] In some embodiments of the present invention, N voltage points are evenly distributed within the ADC sampling range. The ADC sampling range is 0 to 3V, and the N voltage points are evenly distributed within 0 to 3V, such as 0V, 0.3V, 0.6V, 0.9V... The uniform distribution of N voltage points can reduce the computational complexity and can also reduce the sampling error to a certain extent. It should be noted that the specific principle of sampling is a prior art known to those skilled in the art and will not be elaborated here. In addition, the N voltage points can also be unevenly distributed within the ADC sampling range, which can be changed according to actual needs. The specific voltage values ​​taken by the N voltage points can also be determined according to actual needs, and cannot be regarded as a limitation of the present invention.

[0087] In some embodiments of the present invention, the sampling result of each voltage point is obtained by the following steps: after continuous sampling of each voltage point for multiple times, the average value is calculated to obtain the sampling result. The results of continuous sampling of each voltage point for multiple times may not be exactly the same voltage value. Calculating the average value of multiple results and recording them as the sampling result can effectively reduce the sampling error.

[0088] Reference below Figures 2 to 3 An ADC error correction system according to an embodiment of the second aspect of the present invention is described.

[0089] A system for determining a final adjustment parameter group according to an embodiment of the present invention includes:

[0090] A trimming data acquisition unit, used to acquire trimming data, the trimming data including M different pre-selected trimming parameter groups, each pre-selected trimming parameter group including a gain error trimming value and an offset error trimming value;

[0091] A sampling voltage adjustment unit is used to adjust the sampling results of N voltage points based on M pre-selected adjustment parameter groups in sequence to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results includes N adjustment voltage signals; wherein the N voltage points are all within the ADC sampling range;

[0092] An error parameter calculation unit, used for calculating M error parameter groups based on the M groups of adjustment results, each error parameter group including a gain error value and an offset error value;

[0093] A trimming final value parameter determination unit, used to determine a trimming final value parameter group from M different pre-selected trimming parameter groups according to an ADC ideal transfer function and M error parameter groups, wherein the trimming final value parameter group includes a gain trimming final value and an offset trimming final value;

[0094] The error trimming unit is used to trim the ADC gain error and offset error according to the trimming final value parameter group.

[0095] The adjustment data includes M different pre-selected adjustment parameter groups, each of which includes a gain error adjustment value and an offset error adjustment value. Each pre-selected adjustment parameter group is a preset set of accurate values. Specifically, the value range of the gain error adjustment value and the offset error adjustment value is 0 to K-1, where K is an integer. The constraint formula for adjusting the sampling results of N voltage points based on the M pre-selected adjustment parameter groups in sequence is: i =cY+d, where y iThe trimmed voltage signal is the trimmed voltage signal after trimming the sampled voltage signal, Y is the input voltage value of N voltage points, c is the gain, d is the offset, and M groups of trimming results can be obtained after trimming, and each group of trimming results includes N trimming voltage signals. Each group of trimming results can be calculated to obtain an error parameter group, and each error parameter group includes a gain error value and an offset error value.

[0096] like Figure 2 As shown in the figure, the dotted line represents the actual transfer function of the ADC, the dotted line represents the ideal transfer function of the ADC, ActualGain represents the actual gain of the actual transfer function of the ADC, Ideal Gain represents the ideal gain of the ideal transfer function of the ADC, and Actual offset represents the offset error of the actual transfer function of the ADC. The gain error refers to the degree of deviation between the actual transfer function of the ADC and the ideal transfer function of the ADC, and the offset error is the steady-state offset caused in the ADC measurement output result due to the fact that the input signal path and the reference signal path are not exactly the same. Based on the M error parameter groups and the ideal gain of the ideal transfer function of the ADC, the error parameter group whose actual transfer function of the ADC is closest to the ideal transfer function of the ADC can be obtained.

[0097] M different pre-selected adjustment parameter groups are acquired through the adjustment data acquisition unit, each of which includes a gain error adjustment value and an offset error adjustment value. The sampling results of N voltage points are adjusted in turn based on the M pre-selected adjustment parameter groups through the sampling voltage adjustment unit to obtain M groups of adjustment results. The error parameter calculation unit calculates one by one based on the M groups of adjustment results to obtain M error parameter groups, each of which includes a gain error value and an offset error value. Finally, the adjustment final value parameter determination unit determines the adjustment final value parameter group from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups. The gain adjustment final value and the offset adjustment final value in the adjustment final value parameter group obtained have high accuracy. The error adjustment unit then performs high-precision adjustment on the ADC gain error and the offset error according to the gain adjustment final value and the offset adjustment final value to improve the accuracy of the ADC output signal.

[0098] According to the ADC error adjustment system of the embodiment of the present invention, M different pre-selected adjustment parameter groups can be obtained through the adjustment data acquisition unit, each of which includes a gain error adjustment value and an offset error adjustment value. The sampling results of N voltage points are adjusted in turn based on the M pre-selected adjustment parameter groups by the sampling voltage adjustment unit, and M groups of adjustment results can be obtained. The error parameter calculation unit calculates one-to-one based on the M groups of adjustment results to obtain M error parameter groups, each of which includes a gain error value and an offset error value. Finally, the adjustment final value parameter determination unit can determine the adjustment final value parameter group from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups. The gain adjustment final value and the offset adjustment final value in the obtained adjustment final value parameter group have high accuracy, so that the ADC gain error and the offset error can be adjusted with high accuracy by the error adjustment unit according to the gain adjustment final value and the offset adjustment final value, so as to improve the accuracy of the ADC output signal, thereby solving the problem of low adjustment accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0099] Reference below Figure 2 and Figure 4 The error correction device according to the third embodiment of the present invention is described.

[0100] An ADC error adjustment system according to an embodiment of the present invention includes:

[0101] An integrated circuit automatic tester for providing N voltage points;

[0102] An ADC unit, used to sample N voltage points;

[0103] A register for storing trimming data, a gain trimming final value, and an offset trimming final value; the trimming data includes M different pre-selected trimming parameter groups, each pre-selected trimming parameter group includes a gain error trimming value and an offset error trimming value;

[0104] The main control module is used to sequentially adjust the sampling results of N voltage points based on M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results includes N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range; based on the M groups of adjustment results, M error parameter groups are calculated one by one, each error parameter group includes a gain error value and an offset error value; according to the ADC ideal transfer function and the M error parameter groups, a final adjustment parameter group is determined from the M different pre-selected adjustment parameter groups, the final adjustment parameter group includes a gain adjustment final value and an offset adjustment final value; and the ADC gain error and offset error are adjusted according to the final adjustment parameter group.

[0105] First, it should be noted that in the embodiment of the present invention, the ADC sampling range is 0 to 3V, and the N voltage points are all within the range of 0 to 3V, but the ADC sampling range is determined by the ADC itself, and its specific value cannot be regarded as a limitation of the present invention. In addition, the gain error adjustment value and the offset error adjustment value are both natural numbers, but this cannot be regarded as a limitation of the present invention. In some embodiments, the gain error adjustment value and the offset error adjustment value can also be accurate to decimal points and can be preset according to the actual ADC situation. The value of M also needs to be preset according to the actual adjustment range of the gain error adjustment value and the offset error adjustment value.

[0106] like Figure 2 As shown in the figure, the dotted line represents the actual transfer function of the ADC, the dotted line represents the ideal transfer function of the ADC, ActualGain represents the actual gain of the actual transfer function of the ADC, Ideal Gain represents the ideal gain of the ideal transfer function of the ADC, and Actual offset represents the offset error of the actual transfer function of the ADC. The gain error refers to the degree of deviation between the actual transfer function of the ADC and the ideal transfer function of the ADC, and the offset error is the steady-state offset caused in the ADC measurement output result due to the fact that the input signal path and the reference signal path are not exactly the same. Based on the M error parameter groups and the ideal gain of the ideal transfer function of the ADC, the error parameter group whose actual transfer function of the ADC is closest to the ideal transfer function of the ADC can be obtained.

[0107] N different voltage points are given to the channel pin of the ADC unit through the integrated circuit automatic test machine, the ADC clock is turned on, the ADC unit is powered on in simulation, and the ADC unit configuration is initialized to enter the sampling mode, and N different DC voltage signals are sampled. After continuous multiple samplings of each voltage point, the average value is calculated and recorded as the sampling result. M different pre-selected adjustment parameter groups in the register are obtained through the main control module, and the sampling results of the N voltage points are adjusted based on the M pre-selected adjustment parameter groups in turn to obtain M groups of adjustment results. M error parameter groups are calculated based on the M groups of adjustment results in a one-to-one correspondence, each error parameter group includes a gain error value and an offset error value, and according to the ADC ideal transfer function and the M error parameter groups, the adjustment final value parameter group is determined from the M different pre-selected adjustment parameter groups, and the adjustment final value parameter group includes a gain adjustment final value and an offset adjustment final value, and the gain adjustment final value and the offset adjustment final value are written into the register, and finally the ADC gain error and offset error are adjusted according to the gain adjustment final value and the offset adjustment final value. The N different voltage points are all DC voltage signals, and the difficulty and computational complexity of DC voltage signal sampling are lower than that of AC voltage signal sampling. The ADC unit of the embodiment of the present invention can be an ADC module integrated in the chip or an external ADC converter, but this cannot be regarded as a limitation of the present invention.

[0108] According to the error adjustment device of the embodiment of the present invention, N voltage points can be provided by an integrated circuit automatic test machine, and the N voltage points can be sampled by an ADC unit to obtain sampling results of the N voltage points. Adjustment data is stored in a register, and the adjustment data includes M different pre-selected adjustment parameter groups, each of which includes a gain error adjustment value and an offset error adjustment value. The M different pre-selected adjustment parameter groups are obtained by a main control module, and the sampling results of the N voltage points are adjusted based on the M pre-selected adjustment parameter groups in turn, so that M groups of adjustment results can be obtained. Based on the M groups of adjustment results, M error parameter groups are obtained by corresponding calculation, each error parameter group includes a gain error value and an offset error value, and a final adjustment parameter group is determined from M different pre-selected adjustment parameter groups according to an ideal transfer function of the ADC and the M error parameter groups. The gain adjustment final value and the offset adjustment final value in the final adjustment parameter group obtained have high accuracy, so that the ADC gain error and the offset error can be adjusted with high accuracy according to the gain adjustment final value and the offset adjustment final value to improve the accuracy of the ADC output signal, thereby solving the problem of low adjustment accuracy of the gain error and the offset error of the ADC transfer characteristic curve.

[0109] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0110] Although the embodiments of the present invention are described in detail above in conjunction with the accompanying drawings, the present invention is not limited to the above embodiments. Those skilled in the art will understand that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. An ADC error correction method, characterized in that: The following steps are involved: Acquire trimming data, the trimming data comprising M different pre-selected trimming parameter groups, each of the pre-selected trimming parameter groups comprising a gain error trimming value and an offset error trimming value; Sequentially adjusting the sampling results of the N voltage points based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results including N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range; Based on the M groups of trimming results, M error parameter groups are calculated one by one, each of which includes a gain error value and an offset error value; the gain error value and the offset error value in each of the error parameter groups are obtained by the following steps: linear fitting is performed based on the N trimming voltage signals in each group of the trimming results to obtain a fitting straight line, and the gain error value and the offset error value are calculated based on the fitting straight line; The calculation formula of the gain error value is: GainError= |1- ( N* Sum[2] - Sum[0]* Sum[1] ) / SumTemp| ； The calculation formula of the offset error value is: OffsetError = |1- ( Sum[1]* Sum[3] - Sum[0]* Sum[2] ) / SumTemp| ； In the formula, Sum[0]= , Sum[1]= , Sum[2]= , Sum[3]= , SumTemp=N* Sum[3] - Sum[0] * Sum[0] ;in, is the input voltage signal of the preset fitting straight line, is the trimming voltage signal, and N is the number of the selected voltage points; Determine a final adjustment parameter group from the M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups, wherein the final adjustment parameter group includes a gain adjustment final value and an offset adjustment final value; The ADC gain error and offset error are trimmed according to the trimming final value parameter group.

2. The ADC error correction method according to claim 1, characterized in that: The gain adjustment final value is obtained by the following steps: Determining a minimum gain error value among the M gain error values; Determining the preselected trimming parameter set corresponding to the minimum gain error value as a valid trimming parameter set; The gain error trimming value in the valid trimming parameter group is determined as the gain trimming final value.

3. The ADC error correction method according to claim 1, characterized in that: The N voltage points are evenly distributed within the ADC sampling range.

4. The ADC error correction method according to claim 1, characterized in that: The sampling results of each voltage point are obtained by the following steps: After sampling each voltage point multiple times continuously, an average value is calculated to obtain the sampling result.

5. An ADC error correction system, characterized in that: include: A trimming data acquisition unit, used to acquire trimming data, wherein the trimming data includes M different pre-selected trimming parameter groups, each of which includes a gain error trimming value and an offset error trimming value; A sampling voltage adjustment unit, used for adjusting the sampling results of N voltage points based on the M pre-selected adjustment parameter groups in sequence, so as to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, each group of adjustment results including N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range; The error parameter calculation unit is used to calculate M error parameter groups based on the M groups of trimming results in a one-to-one correspondence, each of the error parameter groups includes a gain error value and an offset error value; the gain error value and the offset error value in each of the error parameter groups are obtained by the following steps: performing linear fitting according to the N trimming voltage signals in each group of the trimming results to obtain a fitting straight line, and calculating the gain error value and the offset error value according to the fitting straight line; The calculation formula of the gain error value is: GainError= |1- ( N* Sum[2] - Sum[0]* Sum[1] ) / SumTemp| ； The calculation formula of the offset error value is: OffsetError = |1- ( Sum[1]* Sum[3] - Sum[0]* Sum[2] ) / SumTemp| ； In the formula, Sum[0]= , Sum[1]= , Sum[2]= , Sum[3]= , SumTemp=N* Sum[3] - Sum[0] * Sum[0] ;in, is the input voltage signal of the preset fitting straight line, is the trimming voltage signal, and N is the number of the selected voltage points; A final adjustment parameter determination unit, configured to determine a final adjustment parameter group from M different pre-selected adjustment parameter groups according to an ideal ADC transfer function and the M error parameter groups, wherein the final adjustment parameter group includes a gain adjustment final value and an offset adjustment final value; The error adjustment unit is used to adjust the ADC gain error and offset error according to the adjustment final value parameter group.

6. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer-executable instructions, and the computer-executable instructions are used to enable a computer to execute the ADC error correction method according to any one of claims 1 to 4.

7. An error correction device, characterized in that: include: An integrated circuit automatic tester for providing N voltage points; An ADC unit, used for sampling the N voltage points; A register for storing trimming data, a gain trimming final value, and an offset trimming final value; the trimming data includes M different pre-selected trimming parameter groups, each of which includes a gain error trimming value and an offset error trimming value; A main control module is used to sequentially adjust the sampling results of the N voltage points based on the M pre-selected adjustment parameter groups to obtain M groups of adjustment results corresponding to the M pre-selected adjustment parameter groups, and each group of adjustment results includes N adjusted voltage signals; wherein the N voltage points are all within the ADC sampling range; based on the M groups of adjustment results, M error parameter groups are calculated one by one, and each error parameter group includes a gain error value and an offset error value; the gain error value and the offset error value in each error parameter group are obtained by the following steps: linear fitting is performed based on the N adjusted voltage signals in each group of adjustment results to obtain a fitting straight line, and the gain error value and the offset error value are calculated based on the fitting straight line; The calculation formula of the gain error value is: GainError= |1- ( N* Sum[2] - Sum[0]* Sum[1] ) / SumTemp| ； The calculation formula of the offset error value is: OffsetError = |1- ( Sum[1]* Sum[3] - Sum[0]* Sum[2] ) / SumTemp| ； In the formula, Sum[0]= , Sum[1]= , Sum[2]= , Sum[3]= , SumTemp=N* Sum[3] - Sum[0] * Sum[0] ;in, is the input voltage signal of the preset fitting straight line, is the trimming voltage signal, and N is the number of the selected voltage points; The main control module is also used to determine a final adjustment parameter group from M different pre-selected adjustment parameter groups according to the ADC ideal transfer function and the M error parameter groups, wherein the final adjustment parameter group includes the gain adjustment final value and the offset adjustment final value; and adjust the ADC gain error and offset error according to the final adjustment parameter group.

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