US4893087A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low voltage and low power frequency synthesizer
Assignee: Motorola Solutions Inc
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Filing: 1988-01-07
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Granted: 1990-01-09
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Expires: 2008-01-07
Abstract
Abstract A low power and low voltage frequency synthesizer includes a memory containing information to provide divisor information to the variable divider of a phase locked loop and information to select predetermined values of capacitance to connect to the frequency determining resonant network of the VCO to provide a coarse tuning. This tuning is then further modified by the normal operation of the phase locked loop.
Inventors
- 👤 Walter L. Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:24
CPC Classifications
H; H03; H03J; H03J5/00; H03J5/02; H03J5/0245; H03J5/0272; H03J5/0281; H03L; H03L7/00; H03L7/06; H03L7/08; H03L7/099; H03L7/16; H03L7/18; H03L7/183; H03L7/187; H03J2200/00; H03J2200/10; H03L2207/00; H03L2207/06
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
135 words
A low voltage and low power frequency synthesizer including a variable divider phase locked loop for controlling the output frequency of a voltage controlled oscillator (VCO) comprising: memory means having information corresponding to a desired frequency and divisor information for the phase locked loop and the VCO; and frequency capacitance switch means coupled between said memory and said VCO responsive to additional information to select a predetermined value of capacitance, said switch means including a plurality of capacitors from which the frequency capacitance switch means may select, said switch means further including means producing a course tuning frequency determining network of the VCO whereby a broad range of frequencies can be synthesized at lower voltages and maintained with lower power consumption with the phase locked loop operating to maintain the precision of the desired frequency.
Claim 2
Dependent Claim
135 words
A low voltage and low power frequency synthesizer including a variable divider phase locked loop for controlling the output frequency of a voltage controlled oscillator (VCO) comprising: memory means having information corresponding to a desired frequency and divisor information for the phase locked loop and the VCO; and frequency capacitance switch means coupled between said memory and said VCO responsive to additional information to select a predetermined value of capacitance, said switch means including a plurality of capacitors from which the frequency capacitance switch means may select, said switch means further including means producing a course tuning frequency determining network of the VCO whereby a broad range of frequencies can be synthesized at lower voltages and maintained with lower power consumption with the phase locked loop operating to maintain the precision of the desired frequency.
Claim 3
Dependent Claim
18 words
The frequency synthesizer of claim 1, wherein the memory means further comprises a programmable Read Only Memory (ROM).
Claim 4
Dependent Claim
12 words
The frequency synthesizer of claim 2, wherein said ROM is electrically erasable.
Claim 5
Dependent Claim
21 words
The frequency synthesizer of claim 1, wherein the plurality of capacitance includes at least five values in a binary related sequence.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-01-08 | 1993-07-10 | 1994-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-08 | 1997-07-10 | 1998-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-08 | 2001-07-10 | 2002-01-09 | $7700.00 | Window Closed / Lapsed |