Successive approximation type analog / digital converter and successive approximation type analog / digital conversion method

摘要

PROBLEM TO BE SOLVED: To solve the problem, wherein it is difficult to realized high-speed conversion because of the number of comparison times increases, when the accuracy of parallel comparison is improved in the conventional analog/digital conversion.;SOLUTION: This successive approximation type analog/digital converter includes a sample hold circuit 103, D/A converters 111 to 113, comparators 104 to 106, successive approximation registers 108 to 110, and a timing control circuit 102 and can perform redundant comparison. The comparators successively perform parallel comparison which compares an analog input voltage with each of a plurality of comparison voltages. The successive approximation registers set the next prescribed search voltage range to be within the preceding prescribed search voltage range, on the basis of the result of the parallel comparison, when the result of the parallel comparison is obtained. The timing control circuit generates a signal for switching from parallel comparison to redundant comparison at prescribed timing.;COPYRIGHT: (C)2010,JPO&INPIT