A successive approximation analog-to-digital converter and apparatus

Abstract

The application discloses a successive approximation type analog-digital converter and equipment, and relates to the field of integrated circuits, comprising a sample and hold module, a comparison module, a successive approximation logic module and a capacitor array, wherein the sample and hold module comprises a first transistor, a second transistor and a third transistor. The first transistor to the third transistor constitute a dynamic switch structure, which can isolate the voltage at the first end of the capacitor array from the input signal during the conversion stage of the successive comparison of the reference voltage and the sampling voltage, so that the second transistor in the sample and hold module does not work in the sub-threshold state even when overvoltage is input, thereby ensuring the stability of the voltage at the first end of the capacitor array and further ensuring the precision of the successive approximation type analog-digital converter.

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