Circuits and methods for phase locked loop lock window...

Oscillators – Automatic frequency stabilization using a phase or frequency... – Afc with logic elements

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C331SDIG002

Reexamination Certificate

active

07317359

ABSTRACT:
Circuits and methods for detecting the lock status of a phase locked loop (PLL). The circuit generally comprises (a) a controller configured to produce a control signal in response to a reference clock signal, (b) a counter configured to count pulses of an output signal of the PLL (or a periodic derivative of the output signal) in response to the control signal, and (c) a decoder configured to (i) receive a counter output in response to the control signal, and (ii) produce a lock status output based on the counter output. The method generally comprises the steps of (1) counting pulses of a PLL (or a periodic derivative thereof) in response to a reference clock signal, and (2) indicating a lock status based on the number of counted pulses. The present invention advantageously provides a circuit designer the ability to tune the range of acceptable frequencies by choosing an appropriate reference frequency and adjusting the decoder to produce a positive lock status for a desired range of pulse counts.

REFERENCES:
patent: 5214677 (1993-05-01), Mori
patent: 5327103 (1994-07-01), Baron et al.
patent: 5347232 (1994-09-01), Nishimichi
patent: 5394444 (1995-02-01), Silvey et al.
patent: 5555278 (1996-09-01), Kondoh
patent: 5563552 (1996-10-01), Gersbach et al.
patent: 6762631 (2004-07-01), Kumar
patent: 6765444 (2004-07-01), Wang et al.
patent: 6879195 (2005-04-01), Green et al.
patent: 2005/0073343 (2005-04-01), Kim et al.
patent: 0 367 548 (1990-05-01), None
patent: 0 637 138 (1995-02-01), None
patent: 4-119737 (1992-04-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Circuits and methods for phase locked loop lock window... does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

     

Profile ID: LFUS-PAI-O-2762431

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.