A digital self-calibration device and method for a successive approximation analog-to-digital converter

Abstract

The invention belongs to the field of analog integrated circuit design, and discloses a digital self-calibration device and method of a successive approximation analog-to-digital converter. The digital self-calibration device includes a calibration switch, a comparator and a logic control unit; the digital self-calibration method includes sampling, Select the first calibration capacitor unit for charge redistribution, through the logic control of the lower plate of the capacitor to ground or switch between reference voltages, successively approach the voltage difference caused by the first calibration capacitor unit for charge redistribution, and quantify it through the output of the comparator Calculation: Carry out calibration calculations according to the quantization results, and obtain the calibration results as calibration weight values, which are stored in registers for use in the analog-to-digital converter journey, and are repeated to complete the calibration of all high-level capacitors. The method reduces the area of ​​the circuit by multiplexing the calculation circuit, and at the same time ensures the high-precision quantization of the analog-to-digital converter.

Description

technical field [0001] The invention belongs to the field of analog integrated circuit design, and relates to a digital self-calibration device and method of a successive approximation analog-to-digital converter. Background technique [0002] The main factors restricting the performance of successive approximation analog-to-digital converters include comparator offset, noise influence, capacitance parasitic and capacitance mismatch and other factors. Capacitors often experience random mismatches due to manufacturing process variations. When capacitance mismatch occurs in the capacitor array of the SAR, it will affect the overall linearity of the SAR. Calibrating the capacitance array of the successive approximation analog-to-digital converter is an important technique to improve the linearity of the successive-approximation analog-to-digital converter. Calibration can be divided into digital calibration and analog calibration, and digital calibration includes foreground c...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to overcome the shortcomings of the complex calculation circuit and low precision of the digital front calibration algorithm of the successive approximation analog-to-digital converter in the above-mentioned prior art, and provide a digital self-calibration device of the successive approximation analog-to-digital converter and method

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