Lumped-element RC model for high-data-rate thin-film heads

Abstract

We have developed a lumped-element model for a thin-film giant magnetoresistive head with an inductive writer and used it to study the effect on the data rate capability. Our work shows that the reader can be approximated well by a resistor (R/sub eff/) and a capacitor (C/sub eff/) in parallel. The paper discusses the relative importance of different contributors to C/sub eff/ and addresses the effect of C/sub eff/ on the spectrum of the read-back signal and the electrical reader pulsewidth (PW50) in detail. The model predictions and spin-stand data agree reasonably well. The paper also reports on our study of the amount of writer-to-reader coupling in the transducer. Our work points out the importance of minimizing the parasitic capacitance between elements in the writer and reader and avoiding direct coupling between the writer and reader leads.