Calibration method of capacitor array type successive approximation register analog-to-digital converter

Abstract

Disclosed is a calibration method of a capacitor array type successive approximation register analog-to-digital converter, comprising: obtaining an actual weight value of capacitors of a target bit and an error code between the actual weight value and an ideal weight value of the capacitors of the target bit; calibrating an output code of the SAR ADC to be calibrated with the error code by corresponding addition or subtraction to obtain a final calibrated output code. The calibration method breaks through the requirement that non-binary weights must meet the redundancy, and can realize a weight calibration in a traditional binary ADC and a digital calibration by simple addition and subtraction on the basis of the original code obtained by an analog-to-digital conversion, thus effectively avoiding the error problem in the traditional technology, increasing the calibration precision and accuracy, reducing the circuit complexity and calculation complexity caused by the non-binary weights calibration.