| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which can perform A/D conversion in high precision even when operating at high speed by a simple circuit composition. Ž<P>SOLUTION: A second signal selection unit 13 is prepared in addition to a first signal selection unit 11 which selects an analog signal to be performed A/D conversion out of a plurality of analog signals AN1 to AN8. The second signal selection unit 13 selects analog signals to be performed A/D conversion before the signal selection by the first signal selection unit 11, and output voltage of the second signal selection unit 13 and voltage of a signal line LA are compared by a voltage comparing unit 14. A time to start the A/D conversion by an A/D converter 12 can be shortened since the signal line LA is quickly charged and discharged by a charging and discharging circuit 15 according to the comparison result. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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