US3750153A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Single layer superconducting memory device
Assignee: AT&T Inc
•
Filing: 1972-02-03
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Granted: 1973-07-31
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Expires: 1992-02-03
Abstract
Abstract The disclosed memory device is composed of an array of bistable units. The operational portion of each bistable unit is a strip of superconductor material which can, when suitably d-c biased, be switched between a stable superconducting state and a stable resistive state by the passage of current pulses. A current pulse in the same sense as the bias current switches the unit to a stable resistive state. A pulse of opposite polarity produces the superconducting state. Arrays can be constructed to perform memory and logic functions.
Inventors
- 👤 L Testardi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 05:06
CPC Classifications
H; H03; H03K; H03K3/00; H03K3/02; H03K3/38; G; G06; G06F; G06F7/00; G06F7/38; G06F7/381; G11; G11C; G11C11/00; G11C11/21; G11C11/44; G11C19/00; G11C19/32; Y; Y10; Y10S; Y10S505/00; Y10S505/825; Y10S505/831; Y10S505/833; Y10S505/834
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
96 words
A device comprising an array of bistable units electrically connected to electrical means CHARACTERIZED IN THAT a. each bistable unit consists essentially of a strip of a sputtered layer of superconductor material between 75 angstroms and 1,000 angstroms in thickness and b. the electrical means comprises 1. current bias means for passing a unidirectional bias current through each of the bistable units, 2. current pulse means for passing current pulses of either polarity through each of the bistable units, and 3. sensing means for sensing the resistive state of at least one of the bistable units.
Claim 2
Independent Claim
96 words
A device comprising an array of bistable units electrically connected to electrical means CHARACTERIZED IN THAT a. each bistable unit consists essentially of a strip of a sputtered layer of superconductor material between 75 angstroms and 1,000 angstroms in thickness and b. the electrical means comprises 1. current bias means for passing a unidirectional bias current through each of the bistable units, 2. current pulse means for passing current pulses of either polarity through each of the bistable units, and 3. sensing means for sensing the resistive state of at least one of the bistable units.
Claim 3
Dependent Claim
17 words
current pulse means for passing current pulses of either polarity through each of the bistable units, and
Claim 4
Dependent Claim
17 words
current pulse means for passing current pulses of either polarity through each of the bistable units, and
Claim 5
Dependent Claim
45 words
A device of claim 1 in which the array includes at least one group of series connected bistable units with the sensing means associated with each group including means for sensing the sum of the voltage outputs of the bistable units contained in that group.
Claim 6
Dependent Claim
15 words
sensing means for sensing the resistive state of at least one of the bistable units.
Claim 7
Dependent Claim
15 words
sensing means for sensing the resistive state of at least one of the bistable units.
Claim 8
Dependent Claim
29 words
A device of claim 1 in which the superconductor material contains at least 50 atom percent of one element selected from the group consisting of niobium, tantalum and vanadium.
Claim 9
Dependent Claim
12 words
A device of claim 3 in which the superconductor material is niobium.
Claim 10
Dependent Claim
29 words
A device of claim 3 in which the sensing means includes means for sensing the derivative of the voltage signal appearing across at least one of the bistable units.
Claim 11
Dependent Claim
18 words
A device of claim 3 in which the sputtered layer is between 100 and 200 angstroms in thickness.
Claim 12
Dependent Claim
22 words
A device of claim 6 in which the substrate is held at a temperature between 500* C and 1,300* C during sputtering
Claim 13
Dependent Claim
25 words
A device of claim 7 in which the bias current is no greater than 30 milliamperes per square micrometer of cross-sectional area of the strip.
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) | 1976-07-30 | 1977-01-29 | 1977-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-30 | 1981-01-29 | 1981-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-30 | 1985-01-29 | 1985-07-31 | $7700.00 | Window Closed / Lapsed |