US5684392A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for extending operating time of a battery-operated electronic device
Assignee: International Business Machines Corp
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Filing: 1995-10-03
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Granted: 1997-11-04
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Expires: 2015-10-03
Abstract
Abstract A system supplies power to and controls the frequency of electronic circuitry. The system comprises a DC source for supplying power to the electronic circuitry and a voltage controlled oscillator powered by the DC source. An output of the oscillator provides a system clock for the electronic circuitry such that as a voltage of the DC source continuously drops, the operating voltage of the electronic circuitry and oscillator continuously drops and the frequency of the system clock continuously drops in a manner corresponding to the continuous drop in operating voltage. Thus, the oscillator supplies an operating frequency tailored to the operating voltage to permit the electronic circuitry to operate at high speed.
Inventors
- 👤 Chi Shih Chang
- 👤 Jonathan James Hurd
- 👤 Stephen Francis Newton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:48
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/855; G; G06; G06F; G06F1/00; G06F1/04; G06F1/08; H02J7/90; H02J7/96; H02J2207/00; H02J2207/20
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
92 words
Apparatus for supplying power to and controlling a frequency of a system clock for electronic circuitry, said apparatus comprising: a DC source for supplying an operating voltage for said electronic circuitry; and oscillator means, coupled to said electronic circuitry, for producing a system clock for said electronic circuitry such that as said operating voltage of said electronic circuitry continuously decreases due to a continuous decrease of a voltage of said DC source, the frequency of said system clock continuously decreases in a manner corresponding to the continuous decrease in said operating voltage.
Claim 2
Dependent Claim
92 words
Apparatus for supplying power to and controlling a frequency of a system clock for electronic circuitry, said apparatus comprising: a DC source for supplying an operating voltage for said electronic circuitry; and oscillator means, coupled to said electronic circuitry, for producing a system clock for said electronic circuitry such that as said operating voltage of said electronic circuitry continuously decreases due to a continuous decrease of a voltage of said DC source, the frequency of said system clock continuously decreases in a manner corresponding to the continuous decrease in said operating voltage.
Claim 3
Dependent Claim
28 words
Apparatus as set forth in claim 1 wherein said oscillator means is a ring oscillator and said ring oscillator operates from said operating voltage from said DC source.
Claim 4
Dependent Claim
40 words
Apparatus as set forth in claim 2 wherein said ring oscillator comprises transistors, said electronic circuitry comprises transistors and switching speeds of said ring oscillator transistors and said electronic circuitry transistors are similarly affected by changes in the operating voltage.
Claim 5
Dependent Claim
21 words
Apparatus as set forth in claim 3 wherein said ring oscillator transistors are a same type as said electronic circuitry transistors.
Claim 6
Dependent Claim
37 words
Apparatus as set forth in claim 2 wherein said electronic circuitry comprises a processor powered from said operating voltage and is coupled to receive an output of said ring oscillator as a system clock for said processor.
Claim 7
Dependent Claim
33 words
Apparatus as set forth in claim 1 wherein said DC source comprises a battery and a DC/DC converter powered by said battery and coupled to supply said operating voltage to said electronic circuitry.
Claim 8
Dependent Claim
21 words
Apparatus as set forth in claim 2 wherein said ring oscillator comprises a multiplicity of inverters connected in a ring configuration.
Claim 9
Dependent Claim
85 words
Apparatus as set forth in claim 1 wherein said DC source comprises: a battery exhibiting a higher rated voltage than a rated voltage of said electronic circuitry; a DC/DC converter powered by said battery and outputting said rated voltage of said electronic circuitry when the battery voltage is greater than said rated voltage of said electronic circuitry; and a switch to connect the battery to said electronic circuitry, bypassing said DC/DC converter when the battery voltage drops below the rated voltage of said electronic circuitry.
Claim 10
Dependent Claim
27 words
Apparatus as set forth in claim 2 wherein the frequency of said clock produced by said oscillator means depends on the operating voltage of said oscillator means.
Claim 11
Dependent Claim
107 words
Apparatus for controlling frequency of a system clock for electronic circuitry, said apparatus comprising: a ring oscillator; means for coupling said oscillator and said electronic circuitry to a DC source to receive operating voltage therefrom; and means for coupling a clock output of said oscillator to said electronic circuitry to provide a system clock for said electronic circuitry, as the operating voltage continuously decreases, a frequency of the clock output of said oscillator continuously decreases such that a frequency of said system clock decreases corresponding to reduction in switching speed of transistors within said electronic circuitry, said switching speed continuously decreasing as said operating voltage continuously decreases.
Claim 12
Dependent Claim
107 words
Apparatus for controlling frequency of a system clock for electronic circuitry, said apparatus comprising: a ring oscillator; means for coupling said oscillator and said electronic circuitry to a DC source to receive operating voltage therefrom; and means for coupling a clock output of said oscillator to said electronic circuitry to provide a system clock for said electronic circuitry, as the operating voltage continuously decreases, a frequency of the clock output of said oscillator continuously decreases such that a frequency of said system clock decreases corresponding to reduction in switching speed of transistors within said electronic circuitry, said switching speed continuously decreasing as said operating voltage continuously decreases.
Claim 13
Dependent Claim
40 words
Apparatus as set forth in claim 10 wherein said ring oscillator comprises transistors, said electronic circuitry comprises transistors and switching speed of said ring oscillator transistors and said electronic circuitry transistors are similarly affected by changes in said operating voltage.
Claim 14
Dependent Claim
21 words
Apparatus as set forth in claim 10 wherein said ring oscillator transistors are a same type as said electronic circuitry transistors.
Claim 15
Dependent Claim
35 words
Apparatus as set forth in claim 10 wherein said electronic circuitry comprises a processor powered from said operating voltage and coupled to receive said clock output of said oscillator as a clock for said processor.
Claim 16
Dependent Claim
32 words
Apparatus as set forth in claim 10 wherein said DC source comprises a battery and a DC/DC converter powered by said battery, an output of said DC/DC converter providing said operating voltage.
Claim 17
Dependent Claim
85 words
Apparatus as set forth in claim 10 wherein said DC source comprises: a battery exhibiting a higher rated voltage than a rated voltage of said electronic circuitry; a DC/DC converter powered by said battery and outputting said rated voltage of said electronic circuitry when the battery voltage is greater than said rated voltage of said electronic circuitry; and a switch to connect the battery to said electronic circuitry, bypassing said DC/DC converter when the battery voltage drops below the rated voltage of said electronic circuitry.
Claim 18
Dependent Claim
25 words
Apparatus as set forth in claim 10 wherein the frequency of said clock produced by said oscillator depends on the operating voltage of said oscillator.
Claim 19
Independent Claim
78 words
A method for supplying power to electronic circuitry and controlling a frequency of a clock for said electronic circuitry, said method comprising the steps of: supplying a gradually decreasing operating voltage to said electronic circuitry; and decreasing the clock frequency for said electronic circuitry as said operating voltage gradually decreases such that a switching speed of transistors within said electronic circuitry keeps pace with said clock frequency, said switching speed continuously decreasing as said operating voltage continuously decreases.
Claim 20
Independent Claim
78 words
A method for supplying power to electronic circuitry and controlling a frequency of a clock for said electronic circuitry, said method comprising the steps of: supplying a gradually decreasing operating voltage to said electronic circuitry; and decreasing the clock frequency for said electronic circuitry as said operating voltage gradually decreases such that a switching speed of transistors within said electronic circuitry keeps pace with said clock frequency, said switching speed continuously decreasing as said operating voltage continuously decreases.
Claim 21
Dependent Claim
44 words
A method as set forth in claim 17 wherein the clock frequency is controlled by supplying said clock with said gradually decreasing operating voltage as an operating voltage of said clock, the frequency of said clock depending on the operating voltage of said clock.
Claim 22
Dependent Claim
35 words
A method as set forth in claim 17 wherein said clock is provided by a ring oscillator and said operating voltage is supplied to said ring oscillator as an operating voltage for said ring oscillator.
Claim 23
Dependent Claim
20 words
A method as set forth in claim 19 wherein the clock frequency depends on the operating voltage of said oscillator.
Claim 24
Dependent Claim
41 words
A method as set forth in claim 19 wherein said ring oscillator comprises transistors, said electronic circuitry comprises transistors and switching speed of said ring oscillator transistors and said electronic circuitry transistors are similarly affected by changes in said operating voltage.
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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) | 2000-11-03 | 2001-05-05 | 2001-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-11-03 | 2005-05-05 | 2005-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-11-03 | 2009-05-05 | 2009-11-04 | $7700.00 | Window Closed / Lapsed |