Successive approximation analog-to-digital converter and its digital calibration method and device

Abstract

The invention discloses a successive approximation analog-to-digital converter and its digital calibration method and device. The successive approximation analog-to-digital converter includes a digital-to-analog conversion module DAC, a comparator and a SAR logic unit. The method includes the following steps: obtaining The calibration code of the conversion bit corresponding to the capacitor to be calibrated is converted to the input analog signal in the normal successive approximation mode to obtain a binary conversion value, and the sum of the calibration codes corresponding to the conversion value of 1 in the binary conversion value is calculated; calculation The difference between the binary conversion value and the sum of the calibration code of the conversion bit corresponding to the conversion value of 1 in the quasi-transposition corresponding to the capacitance to be calibrated is obtained to obtain the conversion value of the ADC after verification. The method can effectively calibrate the mismatch error between capacitors caused by parasitic capacitance and process manufacturing error, and avoid the problem of inaccurate double relationship between capacitors caused by mismatch error, thereby effectively improving the accuracy of the ADC.

Description

technical field [0001] The present invention relates to the technical field of analog-to-digital conversion, in particular to a digital calibration method for successive approximation analog-to-digital converters, a non-transitory computer-readable storage medium, and a digital calibration method for successive approximation analog-to-digital converters. device and a successive approximation analog-to-digital converter with the device. Background technique [0002] As a bridge connecting analog signals and digital signals, analog-to-digital converters are developing rapidly in integrated circuits and information industries. The comprehensive advantages of conversion speed, low power consumption and low cost have been widely used. Usually, SARADC is mainly composed of digital-to-analog converter (DAC), comparator, digital control part and other analog circuits, and its core is DAC, comparator and digital control part. [0003] As one of the key units of the charge redistrib...

AI Technical Summary

Problems solved by technology

For this reason, the first purpose of the present invention is to propose a digital calibration method for successive approximation analog-to-digital converters, which can effectively calibrate the mismatch error between capacitances caused by parasitic capacitances and process manufacturing errors, and avoid Mismatch errors cause inaccurate doubling of the relationship between capacitors, which can effectively improve the accuracy of the ADC

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