| 摘要 |
PROBLEM TO BE SOLVED: To obtain an A/D converter whose A/D conversion precision can be improved by taking conversion error trends of an analog input voltage value into consideration. SOLUTION: An offset information storage register 5 stores an offset adjustment value in a format corresponding to bits b0 and b1. An offset value generator 4 is connected to a successive approximation register 2 so that values of the bits b0 and b1 can be read out, and storage contents of the offset information storage register 5 can be referred to. The offset value generator 4 outputs an offset adjustment signal S4 indicating an offset adjustment value OF obtained by reference to an offset information storage register 5 based upon a combination of the bits b0 and b1 after the bits b0 and b1 are determined. A reference voltage generator 3b generates a reference voltage VREF using a ladder resistance unit 3a based upon the offset adjustment signal S4 and bits b0 to bi (i=0 to 9). COPYRIGHT: (C)2008,JPO&INPIT
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