Patent attributes
A calibration method includes the following: providing a first charge quantity to a first input terminal of a comparator; providing a second charge quantity to a second input terminal of the comparator by one of multiple switch capacitor groups, and providing a compensation charge quantity to the second input terminal of the comparator by at least another one of the switch capacitor groups; comparing a voltage value received by the first input terminal and a voltage value received by the second input terminal, and outputting a voltage comparison result to a controller; and if the controller determines the charge quantity provided to the second input terminal approximates to the charge quantity provided to the first input terminal based on the voltage comparison result, recording a calibration charge quantity in a lookup table stored by the controller. An analog-to-digital converter and a calibration apparatus are also provided.