| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a pipeline AD converter circuit whose accuracy varies depending on an input range. <P>SOLUTION: A pipeline AD converter circuit includes a plurality of analog-to-digital converter units 30 and 37 which are serially connected, and a digital operation circuit 38 which calculates a digital conversion value Dout from an analog signal Vin based on a sub-conversion result in the plurality of the analog-to-digital converter units. Each analog-to-digital converter unit 30 includes a sub AD converter 32 and an amplification DA converter 39 which subtracts an analog subtraction signal from an analog input signal depending on a sub-AD value and generates a residual signal and amplifies and outputs the residual signal. The sub AD converter unit 32 on an initial stage divides an input range:-Vref to Vref into at least four sub-ranges and determines which sub-range the analog input signal gets in, and the at least four sub-ranges are different in size. <P>COPYRIGHT: (C)2012,JPO&INPIT |
