Physical Quantity Detection Circuit And Physical Quantity Detection Device

A physical quantity detection circuit includes: a drive circuit configured to apply a drive signal, which includes a first frequency component and a second frequency component having a frequency different from a frequency of the first frequency component, to a drive electrode of a physical quantity detection element; a physical quantity detection signal output circuit configured to output a physical quantity detection signal, based on a first physical quantity component output from a first detection electrode of the physical quantity detection element and a second physical quantity component output from a second detection electrode of the physical quantity detection element; and a first failure diagnosis signal output circuit configured to output a first failure diagnosis signal generated based on a first electrostatic leakage component resulting from the second frequency component propagating to the first detection electrode and a second electrostatic leakage component resulting from the second frequency component propagating to the second detection electrode.