| 摘要 |
PROBLEM TO BE SOLVED: To improve resolution and to enlarge a dynamic range without increasing a consumption current and conversion time by adding capacitors and switches, which operate a sample-and-hold circuit as an integral circuit, connecting the output of a D/A converter to the integral circuit and forming a negative feedback loop. SOLUTION: The sample-and-hold circuit is set to be the integral circuit constituted of plural switches 3-10 and the capacitors 11-13. The integral circuit is fed back so that the negative feedback loop is formed by using reference voltage outputted from the D/A converter 17. A signal is inputted to an analog signal input terminal 1 and control data of the D/A converter 17 is taken out as quantization output. A difference between the input signal and quantization output before one sample is taken and it is integrated and A/D-converted. Thus, the successive comparison-type A/D converter where quantization noise by noise shaping effect is driven to a high frequency area and the dynamic range of a low frequency area improves can he obtained.
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