| 摘要 |
PROBLEM TO BE SOLVED: To provide aΔΣ-type A/D converter, in which a conversion range can be arbitrarily set and which can be set to an optimum conversion range, corresponding to an input signal since a circuit scale has become very large for arrangingΔΣ-type A/D converters and variable gain amplifiers for the respective input signals when a plurality of input signals are dealt with in the conventionalΔΣ-type A/D converter. SOLUTION: AΔΣ-type A/D converter is constituted of a local DA converter, formed of an analog switch operating at a first and a second timing of input 1, an analog switch operating at the first and second timing on input 2, an analog switch operating with the first and second timings irrespective of the selection of input, an SC integrator constituted of a capacitor charged/discharged by the analog switches and an operational amplifier 21, a comparator 22, a D-type flip flop 28, a switch 29 and reference voltage source 30 and 31.
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