← Back to Patent Explorer
US4817199A Expired / Lapsed US ⏱️ 0.0 years remaining

Phase locked loop having reduced response time

Assignee: Boeing North American Inc
•
Filing: 1987-07-17
•
Granted: 1989-03-28
•
Expires: 2007-07-17
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Apparatus and method for reducing the response time for changing a phase locked loop from one frequency to another in which a condition indicative of a frequency change is detected and the conditions in the phase locked loop are changed in response thereto. Specifically, the counts in the loop divider are reset to a predetermined count and an in-phase condition is simulated in the loop phase detector, thereby creating the conditions that are necessary for the phase locked loop to produce the new frequency without the time consuming incremental frequency adjustments that are normally required.

Inventors

  • 👤 Robert W. Wallraff

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-25 11:23
CPC Classifications
H; H03; H03D; H03D13/00; H03D13/003; H03D13/004; H03L; H03L7/00; H03L7/06; H03L7/16; H03L7/18; H03L7/197; H03L7/199; H03L7/08; H03L7/085; H03L7/089

Claims Analysis

Total Claims: 6
Claim 1
Independent Claim 136 words
A phase-locked-loop exhibiting a fast response time, comprising: a voltage controlled oscillator providing an output signal; a phase detector providing an error signal to the voltage controlled oscillator; means providing a reference signal to the phase detector; counter means for dividing the frequency of the output signal of said voltage controlled oscillator and providing a resulting signal to said phase detector; means for detecting the presence of the reference signal; means responsive to the detecting means for resetting said counter means to a predetermined count; means providing an indication of a frequency change; means for providing a preset signal to said phase detector simulating an in-phase relationship between said reference and said variable signals and delay means for maintaining application of said reset signal providing means to said phase detector for a predetermined length of time.
Claim 2
Dependent Claim 136 words
A phase-locked-loop exhibiting a fast response time, comprising: a voltage controlled oscillator providing an output signal; a phase detector providing an error signal to the voltage controlled oscillator; means providing a reference signal to the phase detector; counter means for dividing the frequency of the output signal of said voltage controlled oscillator and providing a resulting signal to said phase detector; means for detecting the presence of the reference signal; means responsive to the detecting means for resetting said counter means to a predetermined count; means providing an indication of a frequency change; means for providing a preset signal to said phase detector simulating an in-phase relationship between said reference and said variable signals and delay means for maintaining application of said reset signal providing means to said phase detector for a predetermined length of time.
Claim 3
Dependent Claim 27 words
A phase locked loop exhibiting a fast response time in accordance with claim 1 wherein said means for providing an indication of frequency change comprises a microprocessor.
Claim 4
Dependent Claim 143 words
A phase-locked-loop exhibiting a fast response time, comprising: a voltage controlled oscillator providing an output signal; a phase detector providing an error signal to the voltage controlled oscillator; means for selectively providing a reference signal to the phase detector; first counter means for dividing the frequency of the output signal of said voltage controlled oscillator and providing a resulting variable signal to said phase detector; second counter means for dividing the frequency of said reference signal; means for detecting the presence of the reference signal; means responsive to the detecting means for resetting said first counter means to a predetermined count; means responsive to said detecting means for resetting said second counter means to a predetermined count; and means responsive to said detecting means for providing a signal to said phase detector simulating an in-phase relationship between said reference and said variable signals.
Claim 5
Dependent Claim 143 words
A phase-locked-loop exhibiting a fast response time, comprising: a voltage controlled oscillator providing an output signal; a phase detector providing an error signal to the voltage controlled oscillator; means for selectively providing a reference signal to the phase detector; first counter means for dividing the frequency of the output signal of said voltage controlled oscillator and providing a resulting variable signal to said phase detector; second counter means for dividing the frequency of said reference signal; means for detecting the presence of the reference signal; means responsive to the detecting means for resetting said first counter means to a predetermined count; means responsive to said detecting means for resetting said second counter means to a predetermined count; and means responsive to said detecting means for providing a signal to said phase detector simulating an in-phase relationship between said reference and said variable signals.
Claim 6
Dependent Claim 52 words
A phase locked loop exhibiting a fast response time in accordance with claim 3 further including delay means for maintaining application of said first and second resetting means to said first and second counter means and of said preset signal providing means to said phase detector for a predetermined length of time.

References Cited (Backward Citations)

US3921095A Cited
US4005479A Cited
US4270210A Cited
US4406017A Cited
US4330758A Cited
US4494079A Cited
JPS5912442A Cited
JPS5922448A Cited
US4451930A Cited
US4607393A Cited
US4634998A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-03-27 1992-09-26 1993-03-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-03-27 1996-09-26 1997-03-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-03-27 2000-09-26 2001-03-28 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag