| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device capable of eliminating an offset by an amplifier connected at an input terminal for an A/D converter. SOLUTION: The semiconductor device has a reference-voltage generating circuit 23 generating a correction reference voltage Vc, a first switch SW1 and a second switch SW2 constituting a changeover circuit changing over an input signal to the amplifier 21 into an analog signal AIN and the correction reference voltage Vc and an internal reset generating section 24a. The A/D converter 25 converts an output signal A1 from the amplifier 21 into a digital signal D1 in a bit number larger than the bit number of the output signal. A register 26 stores the digital signal D1 output from the A/D converter 25 and the A/D converter 25 at a time when the correction reference voltage Vc to the amplifier 21 as a correction data. A computing element 27 arithmetically operates the correction data to the digital signal D1 output from the A/D converter 25 at a time when the analog signal AIN is input to the amplifier 21, and the output signal obtained by converting the result of an arithmetic operation into a specified bit number is output. COPYRIGHT: (C)2006,JPO&NCIPI
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