PHYSICAL QUANTITY DETECTION CIRCUIT, PHYSICAL QUANTITY SENSOR, ELECTRONIC DEVICE, VEHICLE, AND FAILURE DIAGNOSIS METHOD OF PHYSICAL QUANTITY SENSOR

A physical quantity detection circuit includes a detection signal generation circuit that generates a detection signal based on an output signal of a physical quantity detection element, an analog/digital conversion circuit that converts the detection signal into a first digital signal during a first period and converts the first test signal into a second digital signal during a second period, a digital signal processing circuit that processes the first digital signal to generate a third digital signal during the first period and processes a second test signal to generate a fourth digital signal during the second period, and a failure diagnosis circuit that performs a failure diagnosis of the analog/digital conversion circuit based on the second digital signal and a failure diagnosis of the digital signal processing circuit based on the fourth digital signal during the second period.