Patent ID: 10228426

Abstract:
A single chip Z-axis linear magnetoresistive sensor with a calibration/initialization coil comprises a single chip Z-axis linear magnetoresistive sensor, and a calibration coil and/or an initialization coil. The calibration coil and the initialization coil are planar coils or three-dimensional coils. The planar coils are located above a substrate and below a magnetoresistive sensing unit, between a magnetoresistive sensing unit and a soft ferromagnetic flux concentrator, above a soft ferromagnetic flux concentrator, or in a gap of the soft ferromagnetic flux concentrator. The three-dimensional coil is wound around the soft ferromagnetic flux concentrator and the magnetoresistive sensing unit. The calibration coil and the initialization coil respectively comprise straight wires which are parallel to a magnetization direction of a pinned layer/free layer, wherein the calibration coil generates an equivalent calibration magnetic field parallel/anti-parallel to the direction of the pinned layer of a push or a pull magnetoresistive unit string, and the initialization coil generates a uniform initializing magnetic field in the direction of the free layer at all magnetoresistive sensing units. By controlling the current in the calibration coil/initialization coil, calibration and magnetic state initialization of the single chip Z-axis linear magnetoresistive sensor can be achieved. The sensor has advantages of being highly efficient, quick, and convenient.