Physical quantity detection circuit, physical quantity detection apparatus, inertial measurement unit, vehicle positioning apparatus, portable electronic apparatus, electronic apparatus, and vehicle

A physical quantity detection circuit comprising:

• a physical quantity signal generation circuit that generates a physical quantity signal according to magnitude of a physical quantity based on a detection signal output from a physical quantity detection element, the physical quantity detection element being configured to output the detection signal when an external force corresponding to the physical quantity is applied to the physical quantity detection element;
• an abnormality determination circuit that determines whether or not the physical quantity detection element is in a potentially abnormal state based on a value of the physical quantity signal and an amount of change of the value of the physical quantity signal;
• an abnormality diagnostic circuit that generates a test signal input to the physical quantity detection element and diagnoses whether or not the physical quantity detection element is in an abnormal state based on a test detection signal output from the physical quantity detection element in response to the test signal after the abnormality determination circuit determines that the physical quantity detection element is in the potentially abnormal state;
• and
• an interface circuit that transmits a diagnoses result of the abnormality diagnostic circuit to an external device, the diagnoses result corresponding to whether or not the physical quantity detection element is in the abnormal state,
• wherein, when the test signal is input to the physical quantity detection element, the physical quantity detection element is in a test state,
• the test state corresponds to a state in which a predetermined external force is applied to the physical quantity detection element, and the test detection signal corresponds to a physical quantity of the predetermined external force, and
• the abnormality diagnostic circuit compares the test detection signal with a predetermined expected value to diagnose whether or not the physical quantity detection element is in the abnormal state based on a result of the comparison.