SEMICONDUCTOR DEVICE AND ELECTRONIC DEVICE

摘要

Noise in a semiconductor device including a photo sensor is reduced. The semiconductor device includes an analog/digital converter and a photo sensor including a photodiode. The analog/digital converter includes an oscillation circuit(401) and a counter circuit(402). A first signal(311) output from the photo sensor is input to the oscillation circuit(401). The oscillation circuit(401) has a function of outputting a second signal(403) obtained by a change in oscillation frequency of the first signal(311). The counter circuit(402) has a count function by which addition or subtraction is performed by a control signal(407) with the second signal(403) used as a clock signal. The counter circuit(402) performs subtraction during the reset operation of the photo sensor. The counter circuit(402) performs addition during the selection operation of the photo sensor. Thus, output value(321) of the analog/digital converter can be corrected.