A pipeline ADC includes a pipeline structure having a plurality of analog-to-digital
converting units cascaded in series; and a correcting unit coupled to the pipeline
structure for correcting an output value of the pipeline structure according to
a set of calibration constants. One of the analog-to-digital converting units contains
a capacitor switching circuit. During error measurement of the pipeline ADC, the
capacitor switching circuit switches to change capacitance allocation of the analog-to-digital
converting unit so as to obtain the set of calibration constants.