A/D CONVERSION DEVICE AND A/D CONVERSION CORRECTING METHOD

摘要

An A/D conversion unit performs an A/D conversion operation twice during the hold period of the analog value, in the first conversion operation, compares the analog value with a first reference voltage and outputs the result of the comparison as first conversion data, and in the second conversion operation, compares the analog value with a second reference voltage and outputs the result of the comparison as second conversion data. The second reference voltage is a voltage obtained by adding or subtracting a minimum resolution voltage to or from the first reference voltage. A digital processing unit detects an A/D conversion error by averaging errors in the first and second conversion data by digital processing, and controls the voltage by feeding back the result of the detection as a control value to the A/D conversion unit.