Operation circuit having lower calibration time and calibration method thereof

An operation circuit having a lower calibration time, wherein the operation circuit has a variant offset;

• the operation circuit comprising:
• at least one comparator circuit, which is configured to operably compare a first input end of the at least one comparator circuit and a second input end of the at least one comparator circuit, to generate a comparison result according to a difference between the first input end and the second input end, wherein the variant offset includes a first variant offset of the at least one comparator circuit;
• an offset generation circuit coupled to the at least one comparator circuit, wherein the offset generation circuit is configured to operably generate an adjustable offset according to an operation calibration code having N bits, so as to calibrate the variant offset;
• an offset adjustment circuit, which is configured to operably generate the operation calibration code according to the following procedures, so as to calibrate the variant offset:
• procedure P100:
• configuring the operation circuit to a calibration mode and resetting an adjustment parameter to an initial value, and subsequently conducting an initial calibration procedure according to the comparator circuit, to decide the operation calibration code having N bits, wherein N is a positive integer greater than or equal to two;
• procedure P200:
• configuring the operation circuit to an operation mode, and subsequently the operation circuit operating according to the operation calibration code, to conduct a predetermined operation procedure, wherein the operation calibration code corresponds to the adjustable offset and the operation calibration code is configured to operably calibrate the variant offset in the predetermined operation procedure;
• and
• procedure P300:
• configuring the operation circuit to the calibration mode and adjusting a test calibration code according to the adjustment parameter, and subsequently the operation circuit operating according to the test calibration code, to conduct a less bit number calibration procedure, thus updating the adjustment parameter or updating the operation calibration code according to the updated adjustment parameter, wherein the test calibration code is correlated with the operation calibration code, and subsequently proceeding back to the procedure P200.