Patent attributes
A processing speed can be improved while the accuracy of AD conversion is enhanced. An AD converter includes: a higher-order DAC that samples an analog input signal and performs DA conversion corresponding to higher-order bits of a digital output signal; an extension DAC that performs DA conversion to positive and negative polarities on an extension bit for expanding bits of the higher-order DAC; a lower-order DAC that performs DA conversion corresponding to lower-order bits of the digital output signal; a comparator that compares a comparison reference voltage with output voltages of the higher-order DAC, the extension DAC, and the lower-order DAC; and a successive approximation logic that controls successive approximation performed by the higher-order DAC, the extension DAC, and the lower-order DAC based on a comparison result of the comparator and generates the digital output signal.
