| 摘要 |
PROBLEM TO BE SOLVED: To improve characteristics in low voltage in a pipeline or cyclic type AD converter. SOLUTION: A first amplifier circuit 11 samples an input analog signal Vin, and amplifies it into 0.8 times to output the signal to a first subtraction circuit 14. A first AD conversion circuit 12 converts the input analog signal Vin into a digital value to take out high-order four bits (D9-D6). A first DA conversion circuit 13 converts the digital value converted by the AD conversion circuit 12 into an analog value. A first subtracting circuit 14 subtracts an output analog signal of the circuit 13 from an output analog signal of the circuit 11. In this case, the output analog signal from the circuit 13 has already been amplified into 0.8 times. Thus, the amplification factor of the circuit 11 is set at a value lower than 1 to enhance an input voltage range. COPYRIGHT: (C)2005,JPO&NCIPI
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