Linear signal analysis of shielded AMR and spin valve heads

Simple analytic expressions for shielded MR heads are developed for the linear response of both anisotropic and spin valve devices. The analysis is compared with data on a variety of current heads. The results can be utilized to understand the role of parameter variations on signal voltage. Limits on performance due to maximum applied current density and device non-linearities may be readily estimated. It is shown that the area of an isolated pulse is independent of the record spacing, transition shape, and length and thus may be useful for head analysis.