A physical quantity detection circuit which generates a physical quantity detection signal corresponding to a physical quantity based on the first signal and the second signal output from a physical quantity detecting element for detecting the physical quantity, comprising:
- an adder circuit that adds a signal pair based on the first signal and the second signal;
- a synchronous wave-detection circuit that performs synchronous wave-detection on a signal based on the output signal from the adder circuit;
- and
- a vibration leakage signal generation circuit that generates a vibration leakage signal based on an output signal from the synchronous wave-detection circuit.