ANALOG-TO-DIGITAL CONVERTER

摘要

An analog-to-digital converter outputs a reliable digital value corresponding to an input analog value without regard to variation of process, temperature and driving voltage. The analog-to-digital converter includes a voltage comparator for comparing an input voltage with a comparison voltage, a binary up/down counter for up/down converting an outputted binary digital code based on the comparison result of the voltage comparator, a digital-to-analog converting unit for converting the binary digital code that is transferred from the up/down counter as the comparison voltage by using a bias voltage and an offset voltage and for outputting a feedback upper threshold voltage and a feedback lower threshold voltage, and a feedback bias unit for comparing the feedback upper threshold voltage with an upper threshold voltage having the maximum level of the input voltage to output the bias voltage and comparing the feedback lower threshold voltage with a lower threshold voltage having the minimum level of the input voltage to output the offset voltage.