The invention provides a circuit device, a physical quantity detection device, an electronic apparatus and a vehicle. Provided are a circuit device capable of realizing high speed of A/D conversion and suppression of a conversion error, a physical quantity detection device, an electronic apparatus and a vehicle. THe circuit device includes a control circuit having a successive approximation register, a D/A conversion circuit adapted to perform D/A conversion on output data from the successive approximation register, and a comparison circuit adapted to compare an analog input signal and an output signal from the D/A conversion circuit with each other, the control circuit includes an upper limit value register and a lower limit value register adapted to respectively hold an upper limit valueand a lower limit value of a conversion range, and increases the upper limit value or decreases the lower limit value in the case in which the same comparison result has been output by the comparisoncircuit a predetermined number of times or more.