Phase locked loop with limited phase correction when in locked c

Details Phase locked loop with limited phase correction when in locked c Phase locked loop with limited phase correction when in locked c

1983-04-25

1985-09-24

LaRoche, Eugene R.

Oscillators

Automatic frequency stabilization using a phase or frequency...

Afc with logic elements

331DIG2, H03L 700

Patent

active

045435405

ABSTRACT:
A phase locked loop provides limited phase correction when in lock in order to minimize the effects of noise in the periodic input signal to which the loop is locked. The phase locked loop includes a voltage controlled oscillator (VCO), a timing generation divider, a phase detector, a lock detector and an oscillator control circuit. The phase detector provides an output based upon the phase difference between rising edges of the input signal and a loop synthesized signal which is derived by the divider from an oscillator output signal. A window signal, which begins slightly before and ends slightly after an anticipated rising edge of the input signal, is also derived from the oscillator output signal. The lock detector provides a lock detect signal which indicates whether the loop is in lock. The oscillator control circuit provides an oscillator control voltage based upon the phase detector output signal, the window signal, and the lock detect signal. When the loop is in lock, changes to the oscillator control voltage based on the phase detector output are limited by the window signal. When the loop out of lock, full corrections to the oscillator control voltage based upon the phase detector output signal are permitted, so that the loop can rapidly regain the phase locked condition.

REFERENCES:
patent: 3755747 (1973-08-01), Letosky
patent: 4013840 (1977-03-01), Anderson
patent: 4156855 (1979-05-01), Crowley
patent: 4320530 (1982-03-01), Ikeda
patent: 4404530 (1983-09-01), Stryer
Johnson, H. W. "Detection and Correction of Phase Lock Failure in PLO's", IBM Technical Disclosure Bulletin, v. 14, No. 2 (Jul. 71), p. 580.
Rae, J. W. et al., "Variable Frequency Oscillator Using a Frequency Discriminator", IBM Technical Disclosure Bulletin, v. 27, No. 1 (Jun. 84), pp. 355-357.

Affiliated with

Also associated with

Rating

Phase locked loop with limited phase correction when in locked c 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 limited phase correction when in locked c, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase locked loop with limited phase correction when in locked c will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1616301