Lock detect circuit for a phase locked loop

Details Lock detect circuit for a phase locked loop Lock detect circuit for a phase locked loop

2008-01-29

2008-01-29

Pascal, Robert (Department: 2817)

Oscillators

Automatic frequency stabilization using a phase or frequency...

With reference oscillator or source

C331S00100A, C331SDIG002, C327S007000, C327S157000

Reexamination Certificate

active

07323946

ABSTRACT:
An improved system and method for determining the lock condition of a Phase Locked Loop (PLL) is described. The lock detect circuit generates a fast lock detect signal that may be used to detect a transient loss of lock. The lock detect circuit may also include a phase alignment detect circuit to detect a misalignment in the phase of a reference clock and a feedback clock. Additionally, the lock detect circuit may include a reference clock detect circuit to detect if the reference clock signal is detected. Output signals from all of the above circuits may be communicated to a logic circuit in order to create an enhanced lock detect signal. An extended lock detect signal may also be communicated to the logic circuit.

REFERENCES:
patent: 4122405 (1978-10-01), Tietz et al.
patent: 4479091 (1984-10-01), Yoshisato
patent: 4929916 (1990-05-01), Fukuda
patent: 6121849 (2000-09-01), McCollough et al.
patent: 6256362 (2001-07-01), Goldman
patent: 6441691 (2002-08-01), Jones et al.
patent: 6683930 (2004-01-01), Dalmia
patent: 6856202 (2005-02-01), Lesso
patent: 6950957 (2005-09-01), O'Leary
U.S. Appl. No. 11/254,474, filed Oct. 20, 2005, James D. Seefeldt.
U.S. Appl. No. 11/254,281, filed Oct. 20, 2005, Jeffrey J. Kriz.
U.S. Appl. No. 11/254,473, filed Oct. 20, 2005, James D. Seefeldt.
U.S. Appl. No. 11/254,466, filed Oct. 20, 2005, James D. Seefeldt.
Dong Pan, et al, “A Radiation-Hard Phase-Locked Loop,” IEEE 2003, pp. 1-6.
Nosaka, Hideyuki, et al., “A 39-to-45-Gbit/s Multi-Data-Rate Clock and Data Recovery Circuit With a Robust Lock Detector,” IEEE Journal of Solid-State Circuits, vol. 39, No. 8, Aug. 2004, pp. 1361-1365.

Affiliated with

Also associated with

Rating

Lock detect circuit for a phase locked loop does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2800667