Patent ID: 8115664
Filing Date: 2012-02-14
Classification: H03M

Abstract:
1. An A/D conversion device capable of switching between a comparator function and an A/D conversion function, comprising: a sample-and-hold circuit that holds a received input analog voltage; a sequential conversion register that stores a digital value corresponding to a threshold for comparison and determination in the comparator function; a D/A converter that generates an analog voltage corresponding to the digital value stored in the sequential conversion register; a comparator that compares an analog voltage output from the sample-and-hold circuit with an analog voltage obtained from the D/A converter, and outputs a comparison result; a comparison result counter that outputs a determination result according to a count number counted based on the comparison result; and a control circuit that performs control for switching from the comparator function to the A/D conversion function, based on the determination result, wherein, during operation of the A/D conversion function, the sequential conversion register performs an A/D conversion processing for sequentially converting the analog voltage held in the sample-and-hold circuit into a digital value.