A physical quantity detection circuit (12) is used for a physical quantity sensor (10) that outputs a sensor signal according to a physical quantity given externally. A sampling phase adjustment circuit (100) adjusts the phase of a sampling clock (CKa). An analog-to-digital converter circuit (104) converts the sensor signal (Ssnc) to a digital sensor signal (Dsnc) in synchronization with the sampling clock (CKsp) phase-adjusted by the sampling phase adjustment circuit. A detection circuit (107) detects the physical quantity based on the digital sensor signal (Dsnc) from the analog-to-digital converter circuit.