Methods and apparatus for a magnetic field sensor integrated circuit including a lead frame having a first surface, a second opposing surface, and a plurality of leads. A substrate has a first surface supporting a magnetic field sensing element and a second surface attached to the first surface of the lead frame. A magnet has a first surface and a second, opposing surface, and is configured to generate a magnetic field. A spacer is positioned between the first surface of the magnet and the second surface of the lead frame with a thickness selected to establish a predetermined distance between the first surface of the magnet and the magnetic field sensing element, the predetermined distance selected to provide the magnetic field signal as a sinusoidal signal.