| 摘要 |
PROBLEM TO BE SOLVED: To provide a sequential conversion analog-to-digital converter which has a comparator comparing an analog voltage with a reference voltage, and can set the breakdown voltage of an MOS transistor constituting the comparator lower than the maximum voltage of the signal amplitude of an analog input signal. SOLUTION: The analog-to-digital circuit includes a capacitor array including a plurality of first capacitors connected to a common node by the first terminals and subjected to power of 2 weighting, a second capacitor which contributes to voltage attenuation of a common node, a switch array including a plurality of first switches which supply one of the first reference voltage, the second reference voltage or the voltage of an input signal to each first capacitor or interrupt the voltage supply thereto, a second switch which supplies the third reference voltage to the common node or interrupts the third reference voltage supply thereto, a comparator which compares the voltage of the common node with the third reference voltage, and a control circuit which controls the first switches and the second switch. COPYRIGHT: (C)2010,JPO&INPIT
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