TrueTrack (TM) servo technology for high TPI disk drives

The performance of a high track density disk drive is critically limited by positioning errors induced by disk shift, spindle vibration and disk warp- based servomechanics. The spectrally rich error components can be compensat ed for by high-gain digital filters. The filters augment the basic function of a conventional controller, Using a novel method for initializing filter s, precision tracking is achieved without compromising the settle out perfo rmance of a disk drive, An autonomous filter state propagation method durin g seek is shown to simplify the implementation process. A silicon servo chi p has been designed to incorporate the key functions of the algorithm.