SUCCESSIVE APPROXIMATION A/D CONVERTER AND METHOD OF CORRECTIVE CHARGE FOR SUCCESSIVE APPROXIMATION A/D CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a successive approximation A/D converter and a method of corrective charge for a successive approximation A/D converter which can implement normal A/D conversion even if a capacitor of a capacitor array section is disconnected.SOLUTION: A capacitor array element group 2 comprises a parallel arrangement of a plurality of capacitors connected to a signal line 8 and different in capacitance value. A comparator 4 compares the signal line 8 with a ground voltage GND. An error detection section 5 detects an error according to capacitor check information 21 and an expected value table 22. A corrective charge decision section 6 decides a corrective charge number for each of the plurality of capacitors on the basis of the result of error detection and the result of comparison. A storage device 7 stores the corrective charge number for each of the plurality of capacitors. A control circuit 1 controls a corrective charge operation on the plurality of capacitors. A corrective charge circuit 3 correctively charges a capacitor specified by the control circuit 1 from the plurality of capacitors with an electrical charge corresponding to the corrective charge number.