Patent ID: 6847322

Claim:
A sequential comparison type AD converter comprising: series resistors for generating at respective connection portions reference values to convert an analog value to an m-bit digital value; a comparator for sequentially comparing the analog value and one of the reference values and outputting a digital value; a plurality of capacitive elements for distributing any one of the reference values by a capacitance ratio, the plurality of capacitive elements including a first capacitive element and a second capacitive element; and a control unit for switching a value compared to the analog value by the comparator from the reference value to a distribution value of the plurality of capacitive elements when the comparator outputs an m-bit digital value, wherein the analog value is converted to an (m+n) bit digital value, wherein the first capacitive element and second capacitive element are connected in series between any one of the reference values and a ground, and wherein connection portions of the first capacitive element and second capacitive element are connected to inputs of the comparator to which the analog value is not input.