ASYNCHRONOUS DIGITAL PES DEMODULATION DISK DRIVE SERVO CONTROL SYSTEM

摘要

The digital servo control system for a disk drive of the present invention provides asynchronous servo information signal demodulation. The system includes a digital demodulator that removes any phase component of the digitized servo information signal and a burst signal accumulator that sums squared terms according to each burst timing interval to generate a digital quadrature position error position (PES). It includes. The demodulator also suitably comprises a filter having a harmonic notch filter realized by a Hilbert transform filter. Alternatively, the demodulator does not include a filter and a squarer and includes a sum and squarer that sums the squares of the digitized odd and even samples instead of the squarer. The split burst servo pattern for a servo control system is composed of a half-width transition in which phase misalignment does not occur between adjacent magnetic flux patterns, since it can be recorded in a single pass of the recording head.