SUCCESSIVE APPROXIMATION A/D CONVERTER

摘要

PROBLEM TO BE SOLVED: To provide a robust successive approximation A/D converter that avoids falling into a metastable state in a simple configuration.SOLUTION: The successive approximation A/D converter includes: switch groups 105_1 to 105_x connected to opposite ends of corresponding ones of capacitors 106_1 to 106_x to successively selectively switch a capacitor to be applied to successive comparison in response to a switch group control signal Ct1; a comparator 104 for successively comparing a comparison voltage VSN based on a voltage held in the capacitor selected by the switch groups from the capacitors with a predetermined reference voltage VC in synchronization with a timing control signal CLK, and producing a determination output depending on the result of comparison; and a voltage application section 107 for applying a predetermined voltage to the comparison voltage for a predetermined period after a predetermined time passes since the successive comparison on the basis of a voltage application control signal Ct2.