A circuit device includes a D/A converter, a comparator that compares a temperature detection voltage from a temperature sensor unit with a D/A conversion voltage from the D/A converter, and a processing circuit that executes a determination process based on a comparison result from the comparator, and obtains temperature detection data as a result of A/D conversion of the temperature detection voltage, in which, the processing circuit determines the temperature detection data so that a change in the temperature detection data at a second output timing following a first output timing with respect to the temperature detection data at the first output timing is equal to or less than k×LSB.