High-precision successive approximation type analog-digital converter and performance lifting method based on DNL (dynamic noise limiter)

Abstract

The invention provides a high-precision successive approximation type analog-digital converter and a performance lifting method based on a DNL (dynamic noise limiter). The high-precision successive approximation type analog-digital converter comprises a redundancy weight capacitor array, a comparator, a coding and reconstructing circuit, a weight storage circuit and a control logic circuit, wherein the redundancy weight capacitor array is used for acquiring an input voltage on a sampling stage to generate an output voltage, and realizing voltage addition and subtraction operation by controlling the corresponding weight capacitor of the redundancy weight capacitor array according to the comparator output results on the conversion stage; the comparator is used for comparing the output voltage of the redundancy weight capacitor array; the coding and reconstructing circuit is used for calculating an output code of the successive approximation type analog-digital converter according to the comparator output results and the capacitor weight in the weight storage circuit; the weight storage circuit is used for capacitor weight; the control logic circuit is used for controlling the sampling and conversion stage of the redundancy weight capacitor array. The invention further provides the performance lifting method based on the DNL (dynamic noise limiter). According to the high-precision successive approximation type analog-digital converter provided by the invention, the digital correction of capacitor mismatch errors is realized by adopting the capacitor array with the redundancy weight, and the conversion speed and the linear speed are increased.

Description

technical field [0001] The invention belongs to the technical field of digital-to-analog converters, and in particular relates to a high-precision successive approximation analog-to-digital converter and a performance improvement method based on DNL. Background technique [0002] Successive approximation A / D converters usually include comparators, capacitor arrays, successive approximation registers, and control logic circuits. Most of these circuit modules are digital circuits; therefore, as the process size shrinks, successive approximation A / D converters It began to show its innate structural advantages. With the shrinking of the process size, the digital circuit is not only getting faster and faster, the power consumption is getting lower and lower, but also the area is getting smaller and smaller. This is in line with the low power consumption and small size of modern electronic products. consistent needs. Of course, the analog circuits in it also face the problems of ...

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Problems solved by technology

[0011] The traditional capacitor mismatch error correction method usually uses a compensation capacitor array to compensate the capacitor mismatch error. When a certain capacitor participates in the addition and subtraction of charges, the corresponding compensation capacitor array compensates for the charge change caused by the mismatch error. , since the compensation accuracy must be within 1LSB, when the accuracy of the successive approximation A / D converter increases, the compensation capacitor array must adopt a complex structure to achieve high compensation accuracy, so the compensation capacitor array is difficult to achieve

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