| 摘要 |
PROBLEM TO BE SOLVED: To provide a precise comparison result without depending on the threshold of a MOS transistor by using two comparators. SOLUTION: When a voltage V1 from a D/A converter 102 is lower than an input voltage VIN from a sample and hold circuit 103, comparators 104 and 105 output the comparison result signals of H levels. When the voltage V1 is higher than the voltage VIN, the comparison result signal of L level is outputted. A selector 106 selects the output signal of the comparator 104, if the input voltage VIN is not less than the half of a power potential and the output signal of the comparator 105, and if the input voltage VIN is not more than half the power potential based on a selection signal SEL from a controller circuit 101, it is outputted to the controller circuit 101. The controller circuit 101 decides a digital signal value based on a comparison result inputted from the comparators 104 and 105 via the selector 106 and outputs it as an output signal VOUT.
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