US4885552A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oscillator phase control loop having plural switched current sources
Assignee: US Philips Corp
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Filing: 1988-10-05
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Granted: 1989-12-05
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Expires: 2008-10-05
Abstract
Abstract In a phase control loop of an oscillator circuit having an oscillator (1) whose frequency is dependent on a control current (81), an output signal is obtained from a phase detector (13) in the phase control loop and is applied to a switchable (23, 27) first current-source circuit (29) charging a capacitor (35) from which a control signal is obtained which is applied via a second current-source circuit (63) to a control signal input (81) of the oscillator (1). To render the operation of the circuit less dependent on the frequency of phase variations, the second current-source circuit is also switchable (69, 71) by the phase detector (13).
Inventors
- 👤 Arnoldus J. J. Boudewijns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:39
CPC Classifications
H; H03; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/089; H03L7/0891; H03L7/0893; H03L7/0895; H03L7/0898
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
135 words
An oscillator circuit comprising a phase control loop including a phase detector which has a first input coupled to an output of an oscillator, a second input coupled to a comparison signal input of the control loop, and an output circuit coupled to a current-source circuit which is switchable by means of said output circuit for controlling the charge of a capacitor from which a control signal for the oscillator is obtained, characterized in that the capacitor is connected to an input of a voltage-current converter with the aid of which a control current is obtained as a control signal for the oscillator, the frequency of the oscillator being dependent on said control current, and the control current being obtained via a second current-source circuit which is also switchable by means of the phase detector.
Claim 2
Dependent Claim
135 words
An oscillator circuit comprising a phase control loop including a phase detector which has a first input coupled to an output of an oscillator, a second input coupled to a comparison signal input of the control loop, and an output circuit coupled to a current-source circuit which is switchable by means of said output circuit for controlling the charge of a capacitor from which a control signal for the oscillator is obtained, characterized in that the capacitor is connected to an input of a voltage-current converter with the aid of which a control current is obtained as a control signal for the oscillator, the frequency of the oscillator being dependent on said control current, and the control current being obtained via a second current-source circuit which is also switchable by means of the phase detector.
Claim 3
Dependent Claim
35 words
An oscillator circuit as claimed in claim 1, characterized in that it includes a coupling circuit for obtaining a given ratio between the currents supplied by the first current-source circuit and the second current-source circuit.
References Cited (Backward Citations)
US4244043A
Cited
US4774479A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-04 | 1993-06-05 | 1993-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-04 | 1997-06-05 | 1997-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-04 | 2001-06-05 | 2001-12-05 | $7700.00 | Window Closed / Lapsed |