A magnetic field sensor includes at least one coil responsive to an AC coil drive signal; at least one magnetic field sensing element responsive to a sensing element drive signal and configured to detect a directly coupled magnetic field generated by the at least one coil and to generate a magnetic field signal in response to the directly coupled magnetic field; a processor responsive to the magnetic field signal to compute a sensitivity value associated with detection of the directly coupled magnetic field and substantially independent of a reflected magnetic field reflected by a conductive target disposed proximate to the at least one magnetic field sensing element; and an output signal generator configured to generate an output signal of the magnetic field sensor indicative of the reflected magnetic field.