TWI754232B

The present invention suppresses the influence of the variability of a dither signal and stabilize A/D conversion performance in an oversampling A/D conversion device. An A/D conversion device (10) is provided with: a dither signal generation unit (1) that generates a dither signal to be added to an analog input signal; an A/D conversion unit (3) that performs processing for conversing the analog input signal to which the dither signal is added into a digital value; and an averaging processing unit (5) that calculates the average value of the digital values obtained by performing the conversion processing by the A/D conversion unit multiple times within a predetermined period, and outputs the average value as a digital signal after A/D conversion using the predetermined period as a sampling period. The value of the dither signal fluctuates in the range of amplitude corresponding to a value set in the range of 6-260 LSB inclusive in the predetermined period.