Magnetoresistive sensor package with encapsulated initialization coil

A magnetoresistive sensor, comprising:

• a packaging structure;
• at least one pair of sensor chips;
• a substrate having a planar surface;
• a planar-wound initialization coil configured and arranged with respect to the at least one pair of sensor chips to reduce hysteresis and offset, the planar-wound initialization coil having windings formed by a conductor on the planar surface of the substrate, the initialization coil having a coil center surrounded by each of the windings;
• a set of wire bonding pads;
• and
• an encapsulation layer over the substrate to encapsulate the initialization coil;
• wherein the packaging structure comprises the substrate on which a conductor is patterned,
• wherein each of the at least one pair of sensor chips comprises two sensor chips, wherein each of the sensor chips comprises two groups of magnetoresistive sensing unit strings, and the magnetoresistive sensing unit strings located on the sensor chip are connected to form a magnetoresistive sensor bridge,
• wherein the sensor chips are located above the initialization coil and placed symmetrically on opposing sides of the coil center and circumferentially along the surface of the initialization coil and are not placed above the coil center, and a magnetic field generated by the initialization coil is perpendicular to the direction of a sensing axis of the sensor chips.