Patent ID: 6963299
Filing Date: 2005-11-08
Classification: H03M

Abstract:
1. An AD conversion method using an AD converter, said AD converter comprising: an analog input terminal to which a first analog signal to be subjected to AD conversion is input; a DA converter having a resolution of prescribed bits and applied with a high potential and a low potential; a comparator performing a comparison operation between a second analog signal output from said DA converter and said first analog signal; and a digital output terminal outputting a digital signal on the basis of a comparison result output from said comparator, said AD conversion method comprising the steps of: (a) inputting said first analog signal from said analog input terminal; (b) obtaining a first comparison result by performing said comparison operation with a prescribed first high potential and a prescribed first low potential being supplied to said DA converter; (c) switching said first high potential and said first low potential supplied to said DA converter to a second high potential and a second low potential, respectively, on the basis of said first comparison result; (d) obtaining a second comparison result by performing said comparison operation after said step (c); and (e) generating a digital signal on the basis of said first and second comparison results and outputting said digital signal from said digital output terminal.