Patent attributes
A conventional analog-to-digital conversion circuit has a problem that conversion errors cannot be suppressed. According to one embodiment, the analog-to-digital conversion circuit includes a first digital-to-analog conversion circuit 30 of a capacitance distribution type, a second digital-to-analog conversion circuit 31 of a capacitance distribution type, and a comparison circuit 32 for comparing output voltages of the two digital-to-analog conversion circuits, and before performing a successive comparison operation for successively changing a reference voltage applied to the first digital-to-analog conversion circuit, generates an intermediate digital value having a digital value corresponding to a voltage value of an analog input signal, determines a reference voltage to be applied to the second digital-to-analog conversion circuit 31 in accordance with the intermediate digital value, and thereafter performs a successive comparison operation using the first digital-to-analog conversion circuit 30 in a state in which the state of the second digital-to-analog conversion circuit 31 is held.
