Patent US5686867A successfully refreshed from Google Patents.
US5686867A
Expired / Lapsed
US
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Regulated supply for voltage controlled oscillator
Assignee: Cavium International
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Filing: 1996-06-03
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Granted: 1997-11-11
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Expires: 2016-06-03
Abstract
Abstract A monolithic CMOS phase-lock loop (PLL) circuit provides a high frequency of operation suitable for RF applications. The PLL produces an output clock with high spectral purity and very low jitter. The output clock has a low static phase error relative to a reference input, making the PLL useful for clock synchronizing applications, such as clock recovery elements in transmission/recording channels. The PLL provides in-phase and quadrature signals from a voltage controlled oscillator (VCO) which has two differential transconductors. The second differential transconductor has a positive input coupled to a positive output of the first differential transconductor, a negative input coupled to a negative output of the first differential transconductor, a positive output coupled to a negative input of the first differential transconductor, and a negative output coupled to a positive input of the first differential transconductor. Each differential transconductor has a negative output impedance. Each differential transconductor includes a current controlled transconductor circuit (CCXG) and a voltage-current converter coupled to a first supply node for providing a current to the CCXG responsive to a voltage applied to a voltage control input of the differential transconductor.
Inventors
- 👤 Pantas Sutardja
- 👤 Sehat Sutardja
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:22
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/023; H03K3/0231; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/085; H03L7/089; H03L7/0891; H03L7/0895; H03L7/099; H03L7/0995
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
A regulated supply voltage controlled oscillator comprising: an unregulated voltage controlled oscillator having a regulated supply node for receiving a current draw; a current source having an output coupled to the regulated supply node for providing a feed-forward current-draw indicative of a predicted current-draw of the unregulated voltage controlled oscillator; and a low-output impedance voltage buffer coupled to the regulated supply node for providing an error current responsive to the difference between the predicted current-draw and the current-draw of the unregulated voltage controlled oscillator.
Claim 2
Dependent Claim
84 words
A regulated supply voltage controlled oscillator comprising: an unregulated voltage controlled oscillator having a regulated supply node for receiving a current draw; a current source having an output coupled to the regulated supply node for providing a feed-forward current-draw indicative of a predicted current-draw of the unregulated voltage controlled oscillator; and a low-output impedance voltage buffer coupled to the regulated supply node for providing an error current responsive to the difference between the predicted current-draw and the current-draw of the unregulated voltage controlled oscillator.
Claim 3
Dependent Claim
134 words
The regulated supply voltage controlled oscillator of claim 1 wherein the unregulated voltage controlled oscillator is a voltage controlled oscillator comprising: first and second differential transconductors; the first differential transconductor having a positive input, a negative input, a positive output, a negative output, and a voltage control inputs; and the second differential transconductor having a positive input coupled to the positive output of the first differential transconductor, having a negative input coupled to the negative output of the first differential transconductor, having a positive output coupled to the negative input of the first differential transconductor, having a negative output coupled to the positive input of the first differential transconductor, and having a voltage control input coupled to the voltage control input of the first differential transconductor; each differential transconductor having a negative output conductance.
Claim 4
Dependent Claim
128 words
The regulated supply voltage controlled oscillator of claim 2 wherein the first differential transconductor comprises: a voltage-current converter having a first transistor of a first type having a drain coupled to a common source node; a second transistor of the first type having a drain coupled to the negative output of the first differential transconductor, having a source coupled to the common source node, and having a gate coupled to the positive input of the first differential transconductor; and a third transistor of the first type, having a drain coupled to the positive output of the first differential transconductor, having a source coupled to the source of the second transistor of the first type, and having a gate coupled to the negative input of the first differential transconductor.
Claim 5
Dependent Claim
117 words
The regulated supply voltage controlled oscillator of claim 1 wherein the current source comprises: a current mirror having an output connected to the regulated supply node of the unregulated voltage controlled oscillator, and comprising transistors; and; a first transistor of a first type having a gate coupled to the voltage control input of the unregulated voltage controlled oscillator, having a source coupled to a first power supply line, and having a drain coupled to the reference input of the current mirror; the first transistor of the first type and the transistors of the current mirror being sized to have the current mirror produce an output current substantially equal to the current-draw of the unregulated voltage controlled oscillator.
Claim 6
Dependent Claim
55 words
The regulated supply voltage controlled oscillator of claim 1 wherein the low output impedance voltage buffer comprises: an operational amplifier having a positive input connected to a reference voltage signal, having a negative input, and having an output coupled to the negative input of the operational amplifier to form the output of the voltage buffer.
Claim 7
Dependent Claim
51 words
The regulated supply voltage controlled oscillator of claim 1 wherein the low-output impedance voltage buffer comprises a self-bias shunt regulator having an operational amplifier having a power supply input coupled to the regulated supply node and having an output coupled to the power supply input for generating a regulated output voltage.
References Cited (Backward Citations)
US5180995A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-11-10 | 2001-05-12 | 2001-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-10 | 2005-05-12 | 2005-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-10 | 2009-05-12 | 2009-11-11 | $7700.00 | Window Closed / Lapsed |