Patent ID: 7414563

Claim:
An analog-to-digital converter, which converts an input analog signal to a digital value of a predetermined number of bits as a result of a plurality of conversions, the analog-to-digital converter comprising: a conversion unit which converts the input analog signal to a digital value of less than the predetermined number of bits; and a control unit which controls conversion accuracy of said conversion unit, wherein said conversion unit is put to a common use in a plurality n of conversions that include a conversion to the least significant bit, and in a case of n=2, said control unit controls a conversion accuracy of said conversion unit in a manner such that the conversion accuracy of said conversion unit at the time of converting to the least significant bit is set higher than the conversion accuracy of said conversion unit prior to the converting to the least significant bit and, in a case of n≧3, said control unit controls a conversion accuracy of said conversion unit in a manner such that the conversion accuracy of said conversion unit at the time of converting to the least significant bit is set higher than the conversion accuracy of any one of conversions by said conversion unit prior to the converting to the least significant bit.