Phase locked loop with compensation for loop phase errors

Details Phase locked loop with compensation for loop phase errors Phase locked loop with compensation for loop phase errors

1980-10-22

1983-09-13

Grimm, Siegfried H.

Oscillators

Automatic frequency stabilization using a phase or frequency...

Afc with logic elements

331 11, 331 14, 331 16, 331 17, 331 25, H03L 708

Patent

active

044045301

ABSTRACT:
A phase-locked loop circuit is disclosed for use, for example, in the data recovery system of a rotating magnetic disk drive unit employing a phase encoded signal format. The phase-locked loop circuit has a dual mode of operation wherein captive range is assured by providing a first frequency locking mode of operation wherein a voltage controlled oscillator (VCO) is first locked in frequency to a reference signal and a second phase locking mode of operation wherein the VCO is subsequently locked in phase to an MFM signal independently of the frequency assumed by the latter signal. In addition to the VCO, the phase-locked loop circuit includes a frequency detector, a phase detector, a filter, an amplifier, a pair of frequency dividers, a pulse shaping network and a plurality of switches. A potentiometer is coupled to the input of the amplifier and is used to supply a voltage signal to the amplifier which is sized to offset system phase errors caused by the various components in the phase-locked loop circuit. Because system phase errors are minimized, data can be stored and accurately recovered using smaller sized bit cells than would otherwise be possible, resulting in high disk recording frequencies and high density recording.

REFERENCES:
patent: 3321712 (1967-05-01), Frisch et al.
patent: 3832713 (1974-08-01), Rubin
patent: 3852681 (1974-12-01), Underhill
patent: 4069462 (1978-01-01), Dunn
patent: 4107624 (1978-08-01), Turner
patent: 4191976 (1980-03-01), Braun
patent: 4246545 (1981-01-01), Reisfeld
Routledge et al., "A Phase-Locked-Loop Phase-Shifter for Band-Limited Signals", The Radio and Electronic Engineer, vol. 47, pp. 117-120, Mar. 1977.

Affiliated with

Also associated with

Rating

Phase locked loop with compensation for loop phase errors does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Phase locked loop with compensation for loop phase errors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase locked loop with compensation for loop phase errors will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1732508