Patent ID: 7161514

Claim:
The calibration method for an analog-to-digital (A/D) converter comprising: determining calibration values by sine curve fitting for an interleaving A/D converter that repeatedly uses a plurality of A/D conversion devices in a predetermined order, said determining comprising: applying a sine wave as a calibration signal to an input during calibration; A/D converting said sine wave by repeatedly applying a plurality of A/D conversion devices in a predetermined order and storing a sequence of converted data in a data storage memory; and applying said sine curve fitting to the sequence of converted data for each of the plurality of A/D conversion devices and determining a gain, DC offset, and skew calibration values of the plurality of A/D conversion devices; storing the gain, DC offset, and skew calibration values in the calibration memory; during normal interleaving A/D conversion, setting the skew calibration value for each of the plurality of A/D conversion devices in a clock delay provided in each of the plurality of A/D conversion devices; performing interleaving A/D conversion by the plurality of A/D conversion devices; and after A/D conversion, fetching the data stored in the memory, and calibrating the data according to the gain and offset calibration values stored in the calibration memory and outputting the data.