Phase mixer

Pulse or digital communications – Synchronizers – Phase displacement – slip or jitter correction

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Reexamination Certificate

active

06661863

ABSTRACT:

BACKGROUND OF THE INVENTION
The present invention relates to clock synchronization and, particularly, to an improved system and method for locking a signal onto a non-integer multiple of a reference frequency signal.
A phase locked loop (PLL) circuit generates a frequency which is an integer multiple of a reference frequency, usually a stable source such as a crystal oscillator. However, certain applications require a stable signal source which is a non-integer multiple of a stable reference source.
SUMMARY OF THE INVENTION
A phase mixer according to the present invention is provided which generates non-integer multiples of a stable reference source. Briefly, the phase mixer according to one embodiment includes a recirculating shift register and a multiplexer. The shift register output addresses the multiplexer, and the multiplexer in turn selects as the output one of the phases of the reference oscillator. The output of the multiplexer is used to clock the shift register. Because the reference oscillator phases are themselves shifted with reference to one another, sequential selection of the phase pulses as output pulses results in an output which is a non-integer multiple of the reference oscillator frequency.


REFERENCES:
patent: 4668923 (1987-05-01), Lofter
patent: 4802009 (1989-01-01), Hartmeier
patent: 5022056 (1991-06-01), Henderson et al.
patent: 5052031 (1991-09-01), Molloy
patent: 5059924 (1991-10-01), JenningsCheck
patent: 5077529 (1991-12-01), Ghoshal
patent: 5442664 (1995-08-01), Rust et al.
patent: 5448193 (1995-09-01), Baumert et al.
patent: 5561577 (1996-10-01), Motley
patent: 5731743 (1998-03-01), Sauer
patent: 5818365 (1998-10-01), Hush et al.
patent: 5889436 (1999-03-01), Yeung et al.
patent: 6356123 (2002-03-01), Lee et al.
patent: 2 325 803 (1998-12-01), None
Copy of European Search Report for EP Appln. No. 00 106480.7; date search was completed: Jun. 23, 2000.

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

Phase mixer 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 mixer, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Phase mixer will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3129495

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