An integrated magnetoresistive sensor of an AMR (Anisotropic Magneto Resistance) type, formed by a magnetoresistive strip of ferromagnetic material and having an elongated shape with a preferential magnetization direction. A set/reset coil has a stretch, which extends over and transversely to the magnetoresistive strip. A concentrating region, also of ferromagnetic material, extends over the stretch of the set/reset coil so as to form a magnetic circuit for the field generated by the set/reset coil during steps of refresh and maintenance of magnetization of the magnetoresistive coil.