| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an A/D conversion circuit capable of shortening the period required for conversion.SOLUTION: An A/D conversion circuit 1 adapted to convert an analog input signal into a digital amount of (n) bits comprises: a conversion range designation part 30 which designates a conversion range for converting low-order (m) bits while fixing high-order (n-m) bits in the digital amount of (n) bits; a reference value setting part 25 for setting a reference value in such a manner that a predetermined digital amount becomes a center value of the conversion range designated by the conversion range designation part; an arithmetic value setting part 20 for holding an arithmetic value of low-order (m) bits which is arithmetically processed in combination with the reference value set by the reference value setting part and provided so as to be variable in order to set a predictive conversion value; and a conversion control part 50 for comparing an analog conversion signal according to the predictive conversion value of (n) bits with the analog input signal, adjusting the predictive conversion value by performing conversion sequentially from high-order bits in the arithmetic value of low-order (m) bits set by the arithmetic value setting part on the basis of a comparison result, and converting the analog input signal into the digital amount of (n) bits.</p> |
