PID loop filter for timing recovery in a sampled amplitude read

Details PID loop filter for timing recovery in a sampled amplitude read PID loop filter for timing recovery in a sampled amplitude read

1994-11-17

1996-11-05

Chin, Stephen

Pulse or digital communications

Synchronizers

Phase displacement, slip or jitter correction

375350, 375355, 364162, 36472401, H03D 324

Patent

active

055725589

ABSTRACT:
A PID filter employed in a timing recovery phase-locked loop (PLL) for synchronizing the sampling of a read signal from a magnetic read head in a sampled amplitude read channel for magnetic recording. In addition to a proportional and integral term, the PID filter comprises a derivative term to decrease the settling time of the PLL by increasing the phase margin and damping. Consequently, the PLL locks onto the acquisition preamble in a shorter period thereby reducing the necessary preamble length and maximizing storage area for user data. The derivative term of the loop filter is disabled during tracking mode in order to attenuate noise in the phase error and to reduce gain variance associated with tracking arbitrary user data. The structure of the PID loop filter is transformed into an alternative structure in order to minimize the computation path latency between delay registers to avoid limiting the speed of the read channel. To defeat possible harmonic lock conditions caused by non-linearities in the phase-locked loop, a frequency error is added to the accumulation path (integrating path) of the PID filter. A further transformation provides better range and resolution for the PID filter coefficients.

REFERENCES:
patent: 3741474 (1973-06-01), Kawada et al.
patent: 4556956 (1985-12-01), Dickenson et al.
patent: 4890299 (1989-12-01), Dolivo et al.
patent: 5059880 (1991-10-01), Hiroi
patent: 5223778 (1993-06-01), Svarovsky et al.
patent: 5229699 (1993-07-01), Chu et al.
patent: 5258933 (1993-11-01), Johnson et al.
patent: 5309484 (1994-05-01), McLane et al.
patent: 5359631 (1994-10-01), Behrens et al.
Cideciyan, Dolivo, Hermann, Hirt, Schott, "A PRML System for Digital Magnetic Recording", IEEE Journal on Selected Areas in Communication vol. 10, No.1, pp. 38-56, Jan. 1992.
Hong, Wood, Chan, "An Experimental 180 Mb/sec PRML Channel for Magnetic Recording", IBM Storage System Products Division, vol. 27, No. 6, Nov. 1991.

Affiliated with

Also associated with

Rating

PID loop filter for timing recovery in a sampled amplitude read does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with PID loop filter for timing recovery in a sampled amplitude read , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and PID loop filter for timing recovery in a sampled amplitude read will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2020993