ANALOG/DIGITAL CONVERTER AND SELF-DIAGNOSIS METHOD FOR ANALOG/DIGITAL CONVERTER

摘要

PROBLEM TO BE SOLVED: To improve the accuracy of a fault diagnosis of an A/D converter without adding to circuit scale.SOLUTION: An analog/digital converter 80 includes: an input terminal 81 into which an analog input voltage is input; a digital/analog conversion section 82; a comparator 83 for comparing the analog input voltage with an output voltage of the digital/analog conversion section 82; a successive approximation register (SAR) 84 for storing a conversion result output from the comparator; a generation section 85 for adding and subtracting a predetermined value to and from the conversion result held in the successive approximation register 84 to generate additive digital data and subtractive digital data; and a determination section 86 for determining whether or not there is a fault occurring by using results of comparison between the analog input voltage and output levels of the additive digital data and the subtractive digital data converted by the digital/analog conversion section 82.