Patent ID: 9559716
Date: 2017-01-31
CPC Classifications: H03M

Claim:
1. An AD converter comprising: 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 an output voltage of each of the higher-order DAC, the extension DAC, and the lower-order DAC; and a successive approximation logic circuit 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.