An A/D conversion circuit includes a pulse transit circuit, first and second pulse transit position detection circuits, and a digital signal generation circuit. The first pulse transit position detection circuit detects a transit position of the pulse signal output from the pulse transit circuit and generates a logical signal according to the transit position. The second pulse transit position detection circuit detects the circling number of the pulse signal output from the pulse transit circuit and generates a logical signal according to the circling number. The digital signal generation circuit synthesizes the logical signals output from the first and second pulse transit position detection circuits and generates a digital signal according to a size of an analog signal VA. The pulse transit circuit is configured so that a sum of the number of the inverting circuits that the pulse signal transits in an N-th period (N denotes a natural number) and the number of the inverting circuits that the pulse signal transits in an (N+1)-th period is a power of 2.