A sensor is provided having a magnetic field sensing element to generate a magnetic field signal, a switching circuit coupled to receive the magnetic field signal and generate a switching signal that changes a polarity of the magnetic field signal at a predetermined frequency, and a comparison device configured to receive the switching signal and generate an output signal that changes a level in response to the switching signal crossing a predetermined threshold. The switching circuit is disposed between the magnetic field sensing element and the comparison device and can provide the comparison device an input signal (i.e., the switching signal) that changes polarity at the predetermined frequency. The comparison device can sense characteristics, such as but not limited to crossing operate and release threshold levels, of both north and south polarity magnetic field signals using the switching signal.