US4855690A
Expired / Lapsed
US
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Integrated circuit random number generator using sampled output of variable frequency oscillator
Assignee: Maxim Integrated Products Inc
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Filing: 1988-11-01
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Granted: 1989-08-08
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Expires: 2008-11-01
Abstract
Abstract An integrated circuit random number generator which uses a triangular output analog oscillator to vary the frequency of a higher frequency voltage controlled oscillator. The output of the voltage controlled oscillator is sampled at a rate much less than the rate of oscillation of the voltage controlled oscillator to produce random digital values.
Inventors
- 👤 Donald R. Dias
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:05
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/58; G06F7/588; H; H03; H03K; H03K3/00; H03K3/02; H03K3/023; H03K3/0231; H03K3/027; H03K3/03; H03K3/0315; H03K3/0322; H03K3/84
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
81 words
An integrated circuit random number generator, comprising: an analog oscillator; a digital oscillator, comprising multiple digital stages connected together, multiple ones of said stages being connected to be controlled by the output voltage of said analog oscillator; and a sampling circuit, connected to sample the output of said digital oscillator with a timing which is independent of the operation of said digital oscillator; wherein the highest frequency of said analog oscillator is less than the lowest frequency of said digital oscillator.
Claim 2
Dependent Claim
81 words
An integrated circuit random number generator, comprising: an analog oscillator; a digital oscillator, comprising multiple digital stages connected together, multiple ones of said stages being connected to be controlled by the output voltage of said analog oscillator; and a sampling circuit, connected to sample the output of said digital oscillator with a timing which is independent of the operation of said digital oscillator; wherein the highest frequency of said analog oscillator is less than the lowest frequency of said digital oscillator.
Claim 3
Dependent Claim
25 words
The integrated circuit of claim 1, wherein the highest frequency of said analog oscillator is much less than the lowest frequency of said digital oscillator.
Claim 4
Dependent Claim
12 words
The integrated circuit of claim 1, wherein said analog oscillator is free-running.
Claim 5
Dependent Claim
19 words
The integrated circuit of claim 1, wherein the lowest frequency of said digital oscillator is at least 40 MHz.
Claim 6
Dependent Claim
18 words
The integrated circuit of claim 1, wherein the range of frequencies of said digital oscillator includes 80 MHz.
Claim 7
Dependent Claim
83 words
An integrated circuit random number generator, comprising: a free-running analog voltage generator circuit; a ring oscillator, multiple stages of said ring oscillator being conneted to be controlled by the output voltage of said analog voltage generator circuit; and a sampling circuit, connected to sample the output of said ring oscillator with a timing which is independent of the operation of said ring oscillator; wherein the highest frequency of said analog voltage generator circuit is less than the lowest frequency of said ring oscillator.
Claim 8
Dependent Claim
83 words
An integrated circuit random number generator, comprising: a free-running analog voltage generator circuit; a ring oscillator, multiple stages of said ring oscillator being conneted to be controlled by the output voltage of said analog voltage generator circuit; and a sampling circuit, connected to sample the output of said ring oscillator with a timing which is independent of the operation of said ring oscillator; wherein the highest frequency of said analog voltage generator circuit is less than the lowest frequency of said ring oscillator.
Claim 9
Dependent Claim
19 words
The integrated circuit of claim 6, wherein the lowest frequency of said ring oscillator is at least 40 MHz.
Claim 10
Dependent Claim
18 words
The integrated circuit of claim 6, wherein the range of frequencies of said ring oscillator includes 80 MHz.
Claim 11
Dependent Claim
27 words
The integrated circuit of claim 6, wherein the highest frequency of said analog voltage generator circuit is much less than the lowest frequency of said ring oscillator.
Claim 12
Dependent Claim
88 words
An integrated circuit random number generator, comprising: a capacitively loaded analog oscillator; a ring oscillator comprising multiple inverter stages, multiple respective ones of said inverter stages being connected in series with load transistors which are controlled by the output voltage of said analog oscillator; and a sampling circuit, connected to sample the output of said ring oscillator with a timing which is independent of the operation of said ring oscillator; wherein the highest frequency of said analog oscillator is less than the lowest frequency of said ring oscillator.
Claim 13
Dependent Claim
88 words
An integrated circuit random number generator, comprising: a capacitively loaded analog oscillator; a ring oscillator comprising multiple inverter stages, multiple respective ones of said inverter stages being connected in series with load transistors which are controlled by the output voltage of said analog oscillator; and a sampling circuit, connected to sample the output of said ring oscillator with a timing which is independent of the operation of said ring oscillator; wherein the highest frequency of said analog oscillator is less than the lowest frequency of said ring oscillator.
Claim 14
Dependent Claim
25 words
The integrated circuit of claim 10, wherein the highest frequency of said analog oscillator is much less than the lowest frequency of said ring oscillator.
Claim 15
Dependent Claim
12 words
The integrated circuit of claim 10, wherein said analog oscillator is free-running.
Claim 16
Dependent Claim
19 words
The integrated circuit of claim 10, wherein the lowest frequency of said ring oscillator is at least 40 MHz.
Claim 17
Dependent Claim
18 words
The integrated circuit of claim 10, wherein the range of frequencies of said ring oscillator includes 80 MHz.
References Cited (Backward Citations)
US4001817A
Cited
US4644299A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |