BINARY CAPACITOR ARRAY APPLIED TO SINGLE-TERMINAL SAR ADC AND REDUNDANCY CALIBRATING METHOD THEREFOR

摘要

Disclosed is a redundancy calibrating method for a binary capacitor array applied to a single-terminal SAR ADC. The method can be used for calibrating a dynamic error of the binary capacitor array caused by incomplete establishment. The method comprises a redundantly calibrated binary capacitor array, a comparer, an SAR logical control module and an output code computation module. The redundantly calibrated binary capacitor array comprises a binary capacitor array and an addition redundancy capacitor and a subtraction redundancy capacitor. According to the calibration method, a redundancy capacitor is inserted on the basis of a binary capacitor DAC array to realize that multiple digital codes correspond to one ADC analog input; whether an error exists is detected during redundant bit conversion; the addition redundancy capacitor or the subtraction redundancy capacitor is operated according to corresponding situations to compensate for the generated error.