We present the results of experimental and theoretical studies of the influence on the characteristics of anisotropic magnetoresistive magnetic field sensors based on FeNiCo alloy with a “barber-pole” structure of their own current. A significant difference has been established between the volt–oersted performance of forward and reverse running with an increase in the current caused by the input voltage supply at sufficiently large external magnetic fields. A theoretical calculation of the volt–oersted performance is carried out within the framework of the model of one-dimensional inhomogeneity of the magnetization distribution. The obtained performance coincides with the experimental data for forward running.