Calibration circuit of analog-to-digital converter

The invention relates to the technical field of integrated circuits, and discloses a calibration circuit of an analog-to-digital converter, which comprises a known sequence error matrix calculation circuit for obtaining framing information from an optical digital signal processor and a data stream after damage elimination so as to calculate an error matrix; the first known sequence recovery circuit is used for sampling data between the optical channel and the analog-to-digital converter and obtaining a first known sequence data stream according to the framing information and the error matrix; the second known sequence recovery circuit is used for sampling data between the analog-to-digital converter and the optical digital signal processor and obtaining a second known sequence data stream according to the framing information and the error matrix; the calibration control word generating circuit is used for generating proportional, offset and delay calibration control words according to the first known sequence