Decomposition of Baseline Noise Sources in Hard Disk Position Error Signals Using the PES Pareto Method

This paper uses the PES Pareto Method[1] and measurement techniques for isolating noise sources[2] to decompose the Position Error Signal (PES) of a Lynx II hard disk drive manufactured by Hewlett-Packard. This accomplishes three things: it demonstrates the utility of the PES Pareto Method in a practical example, it allows us to discover which noise sources are insignificant to PES, and it identifies which noise sources are significant to PES. In this particular hard disk drive, it is discovered that the two most significant sources of baseline noise at the disk’s position error signal are the turbulent wind flow generated by the spinning disks (Windage) and the noise involved in the actual readback of the Position Error Signal (Position Sensing Noise).