Patent US2697986A successfully refreshed from Google Patents.
Patent US5870445A successfully refreshed from Google Patents.
US5870445A
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Frequency independent clock synchronizer
Assignee: Raytheon Co
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Filing: 1995-12-27
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Granted: 1999-02-09
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Expires: 2015-12-27
Abstract
Abstract A clock distribution system including a variable delay circuit responsive to a reference clock signal having a fixed clock pulse width and a variable clock period for providing a delayed clock signal, an inverter for inverting the delayed clock signal to an inverted delayed clock signal, a clock tree for providing multiple replicas of the inverted delayed clock signal, a comparator responsive to the reference clock signal and a selected one of the multiple replicas of the inverted delayed clock signal for controlling the variable delay circuit such that the selected replica is delayed by one clock pulse width relative to the reference clock signal. Also disclosed is a shift register controlled variable delay line that can be implemented in the variable delay circuit.
Inventors
- 👤 William D. Farwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:44
CPC Classifications
G; G06; G06F; G06F1/00; G06F1/04; G06F1/10; H; H04; H04L; H04L7/00; H04L7/0016; H04L7/0033; H04L7/0037
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A variable delay line comprising: a plurality of digital inverters connected in series and arranged in a sequence wherein the first inverter in sequence receives an input digital signal which is propagated through the inverters in sequence; a plurality of two-input inverting multiplexers respectively associated with digital inverters and arranged in a corresponding sequence wherein each multiplexer receives an input from an associated one of said inverters, each multiplexer except for the last in sequence further receiving an input from a multiplexer that is next in sequence, such that the output of the first in sequence multiplexer comprises an output of the delay line, and such that each inverter and its associated multiplexer forms an inverter/multiplexer delay stages; and a shift register having a plurality of stages for respectively controlling said plurality of inverting multiplexers.
Claim 2
Dependent Claim
135 words
A variable delay line comprising: a plurality of digital inverters connected in series and arranged in a sequence wherein the first inverter in sequence receives an input digital signal which is propagated through the inverters in sequence; a plurality of two-input inverting multiplexers respectively associated with digital inverters and arranged in a corresponding sequence wherein each multiplexer receives an input from an associated one of said inverters, each multiplexer except for the last in sequence further receiving an input from a multiplexer that is next in sequence, such that the output of the first in sequence multiplexer comprises an output of the delay line, and such that each inverter and its associated multiplexer forms an inverter/multiplexer delay stages; and a shift register having a plurality of stages for respectively controlling said plurality of inverting multiplexers.
Claim 3
Dependent Claim
15 words
The delay line of claim 1 wherein said inverter/multiplexer delay stages provide substantially identical delays.
Claim 4
Dependent Claim
13 words
The delay line of claim 1 wherein said inverter/multiplexer stages provide different delays.
Claim 5
Dependent Claim
15 words
The delay line of claim 1 wherein said shift register comprises a bidirectional shift register.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2002-02-08 | 2002-08-10 | 2003-02-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-02-08 | 2006-08-10 | 2007-02-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-02-08 | 2010-08-10 | 2011-02-09 | $7700.00 | Window Closed / Lapsed |