Patent ID: 7605738

Claim:
An A/D converter that outputs a digital output signal obtained by digitalizing an analog input signal, comprising: a bit selecting section that selects a conversion object bit from a high-order bit to a low-order bit of the digital output signal in order; a threshold-value controlling section that determines a threshold data expressing a boundary value between zero and one of the conversion object bit on the basis of an already-determined value of a higher-order bit than the conversion object bit; a D/A converting section that digital-to-analog converts the threshold data and generates an analog threshold value; a comparing section that compares, at a plurality of different timings in a conversion time interval determining a value of the conversion object bit, the analog input signal and the analog threshold value and outputs a plurality of comparison results at the timings; and a bit determining section that determines the value of the conversion object bit on the basis of the plurality of comparison results.