Sensitivity study of partial response maximum likelihood and peak detection channels to contamination buildup on air bearing surface of proximity recording sliders

Abstract

This work investigates experimentally the sensitivity of partial response maximum likelihood (PRML) and peak detection channels on the increased head-disk spacing caused by the contamination buildup on the slider's air bearing surfaces (ABS). Results obtained indicate that the peak detection channel is sensitive to both the Transition Effect (writing at increased head-disk spacing) and the Readout Resolution Effect (reading at increased head-disk spacing). The increased error rate detected in peak detection channel at increased head-disk spacing can be reduced significantly if the spacing is resumed to normal. In fact, the influence of the transition effect on the peak detection channel is more significant than the readout resolution effect. The PRML channel, however, is mostly sensitive to the transition effect only. The resolution effect, conversely, has rather limited impact on the PRML channel. Off-track sensitivity studies shows that peak shift in the peak detection channel becomes more sensitive to off-track positions when the head-disk spacing is increased. The nonlinear transition shift in the PRML channel, on the contrary, is far less sensitive to the off-track of magnetic head, even when the spacing is increased by the contamination buildup. © 1997 American Institute of Physics.