Physical quantity sensor and inertial measurement unit

A physical quantity sensor comprising:

• a physical quantity detection element coupled to a first terminal, a second terminal, and a third terminal;
• and
• a physical quantity detection circuit,
• wherein the physical quantity detection circuit has:
• a drive circuit that drives the physical quantity detection element;
• a signal generation circuit that generates a physical quantity signal corresponding to a magnitude of a physical quantity based on a detection signal output from the physical quantity detection element;
• a determination circuit that determines whether a value of the physical quantity signal continuously remains within a predetermined range in a predetermined period, determines that the physical quantity detection element is in a first state of normal operation when the value does not continuously remain, and determines that the physical quantity detection element is in a second state of abnormal operation when the value continuously remains;
• a control circuit that stores the physical quantity signal and setting information;
• a communication section that outputs the physical quantity signal to an outside;
• a voltage generation circuit that generates a bias voltage applied to the physical quantity detection element;
• and
• switching circuits that perform switching between a coupled state and a decoupled state between the physical quantity detection element and the drive circuit and between the physical quantity detection element and the voltage generation circuit, wherein
• the control circuit stores first information based on a determination result of the determination circuit as the setting information,
• the communication section outputs the setting information stored in the control circuit to the outside when the determination result of the determination circuit indicates the second state;
• when the determination result of the determination circuit indicates the first state, the control circuit controls the switching circuits to put the physical quantity detection element and the drive circuit into the coupled state and to put the physical quantity detection element and the voltage generation circuit into the decoupled state, and controls the drive circuit to repeatedly apply a first voltage, a second voltage, and a third voltage from the first terminal to the physical quantity detection element in an order of the first voltage, the second voltage, and the third voltage, and
• the signal generation circuit generates the physical quantity signal.