US3922602A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lock detector for a phase locked loop
Assignee: Motorola Solutions Inc
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Filing: 1974-10-11
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Granted: 1975-11-25
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Expires: 1994-10-11
Abstract
Abstract A quadrature phase detector connected to a phase locked loop so as to receive a first signal from a voltage controlled oscillator in the loop and a second signal from the reference oscillator in the loop, one of said signals being shifted 90*, and providing a pair of differential outputs through resistance elements to the collectors of a pair of common emitter connected transistors in a differential amplifier. The collectors of the transistors are coupled to a voltage source so as to provide a positive feedback to the differential amplifier, and the control electrodes are connected directly to the differential outputs of the phase detector so that the differential amplifier provides two discrete output voltage levels at either of the collectors, which levels indicate lock or unlock in the phase locked loop.
Inventors
- 👤 Richard Eli Lunquist
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:19
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/087; G; G01; G01R; G01R25/00; G01R25/04; H03L7/095; Y; Y10; Y10S; Y10S331/00; Y10S331/02
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A lock detector for a phase locked loop including a voltage controlled oscillator and a reference oscillator, said lock detector comprising: a. a phase detector having first and second inputs and a pair of differential outputs; b. said phase detector being coupled to the loop with the first input receiving an output signal from the voltage controlled oscillator and the second input receiving an output signal from the reference oscillator; c. a differential amplifier having a pair of inputs connected to the differential outputs of said phase detector and further having a pair of outputs; and d. means coupling the differential outputs of said phase detector to the pair of outputs of said differential amplifier for providing a positive feedback to cause said differential amplifier to provide two discrete voltage levels at the outputs thereof.
Claim 2
Dependent Claim
135 words
A lock detector for a phase locked loop including a voltage controlled oscillator and a reference oscillator, said lock detector comprising: a. a phase detector having first and second inputs and a pair of differential outputs; b. said phase detector being coupled to the loop with the first input receiving an output signal from the voltage controlled oscillator and the second input receiving an output signal from the reference oscillator; c. a differential amplifier having a pair of inputs connected to the differential outputs of said phase detector and further having a pair of outputs; and d. means coupling the differential outputs of said phase detector to the pair of outputs of said differential amplifier for providing a positive feedback to cause said differential amplifier to provide two discrete voltage levels at the outputs thereof.
Claim 3
Dependent Claim
39 words
A lock detector as claimed in claim 1 wherein the phase detector is a quadrature phase detector and one of the output signals from the voltage controlled oscillator and the reference oscillator is coupled through a phase shifting network.
Claim 4
Dependent Claim
19 words
A lock detector as claimed in claim 2 wherein the phase shifting network is approximately a 90* phase shift.
Claim 5
Dependent Claim
63 words
A lock detector as claimed in claim 1 wherein the coupling means includes a first resistor in each of the pair of differential outputs of the phase detector and a second resistor in each of the outputs of the pair of outputs of the differential amplifier, each of said first resistors being connected in series with a different one of said second resistors.
Claim 6
Dependent Claim
197 words
A lock detector for a phase locked loop including a voltage controlled oscillator and a reference oscillator, said lock detector comprising: a. a phase detector having first and second inputs and a pair of emitter coupled transistors each having a collector serving as an output; b. said phase detector being coupled to the loop with the first input receiving an output signal from the voltage controlled oscillator and the second input receiving an output signal from the reference oscillator; c. a differential amplifier including a pair of emitter coupled transistors each having a collector connected to a power supply through separate resistors, said collectors serving as outputs of said differential amplifier, and each having a control electrode connected to a different one of the collectors of said phase detector for supplying input signals to said differential amplifier; and d. a pair of resistors each coupled at one end to a different collector of said transistors in said differential amplifier and each coupled at the other end to a different collector of said transistors in said phase detector for providing a positive feedback to cause said differential amplifier to provide two discrete voltage levels at the outputs thereof.
Claim 7
Dependent Claim
197 words
A lock detector for a phase locked loop including a voltage controlled oscillator and a reference oscillator, said lock detector comprising: a. a phase detector having first and second inputs and a pair of emitter coupled transistors each having a collector serving as an output; b. said phase detector being coupled to the loop with the first input receiving an output signal from the voltage controlled oscillator and the second input receiving an output signal from the reference oscillator; c. a differential amplifier including a pair of emitter coupled transistors each having a collector connected to a power supply through separate resistors, said collectors serving as outputs of said differential amplifier, and each having a control electrode connected to a different one of the collectors of said phase detector for supplying input signals to said differential amplifier; and d. a pair of resistors each coupled at one end to a different collector of said transistors in said differential amplifier and each coupled at the other end to a different collector of said transistors in said phase detector for providing a positive feedback to cause said differential amplifier to provide two discrete voltage levels at the outputs thereof.
Claim 8
Dependent Claim
40 words
A lock detector as claimed in claim 5 wherein the phase detector is a quadrature phase detector and one of the output signals from the voltage controlled oscillator and the reference oscillator is coupled through a 90* phase shifting network.
References Cited (Backward Citations)
US3863080A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |