US4292675A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Five device merged transistor RAM cell
Assignee: International Business Machines Corp
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Filing: 1979-07-30
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Granted: 1981-09-29
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Expires: 1999-07-30
Abstract
Abstract A five device RAM cell comprising a four device Merged Transistor Logic (MTL) cell plus a separate sense line and a fifth bipolar transistor device having a collector connected to one node of the cell, a base connected to the other node of the cell, and an emitter connected to the sense line.
Inventors
- 👤 Bernard A. Denis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:41
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/401; G11C11/402; G11C11/4026; G11C11/41; G11C11/411; G11C11/4113; G11C8/00; G11C8/16; H; H10; H10B; H10B10/00; H10B10/10
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
A bipolar transistor memory array cell, each transistor of said cell having collector, base and emitter, said cell comprising: a pair of flip-flop cross-connected transistors having a pair of nodes corresponding to the collectors of said cross-connected transistors, a pair of bit lines, a word line, a pair of input-output transistors of a type complementary to said flip-flop transistors connecting said nodes to said bit lines via the emitter-collector current paths thereof, the bases of said input-output transistors and the emitters of said cross-connected transistors being connected to said word line, a sense line, and a sense transistor, the collector of said sense transistor being connected to one of said nodes; the base of said sense transistor being connected to the other of said nodes, and the emitter of said sense transistor being connected to said sense line.
Claim 2
Dependent Claim
138 words
A bipolar transistor memory array cell, each transistor of said cell having collector, base and emitter, said cell comprising: a pair of flip-flop cross-connected transistors having a pair of nodes corresponding to the collectors of said cross-connected transistors, a pair of bit lines, a word line, a pair of input-output transistors of a type complementary to said flip-flop transistors connecting said nodes to said bit lines via the emitter-collector current paths thereof, the bases of said input-output transistors and the emitters of said cross-connected transistors being connected to said word line, a sense line, and a sense transistor, the collector of said sense transistor being connected to one of said nodes; the base of said sense transistor being connected to the other of said nodes, and the emitter of said sense transistor being connected to said sense line.
Claim 3
Dependent Claim
23 words
The cell defined in claim 1 wherein said cross-connected transistors are NPN transistors and said input-output and said sense transistors are PNP transistors.
Claim 4
Dependent Claim
18 words
The cell defined in claim 2 wherein said NPN transistors are vertical transistors operated in the inverse mode.
Claim 5
Dependent Claim
13 words
The cell defined in claim 2 wherein said input-output transistors are lateral transistors.
Claim 6
Dependent Claim
14 words
The cell defined in claim 2 wherein said sense transistor is a vertical transistor.
Claim 7
Dependent Claim
31 words
The cell defined in claim 2 wherein the bases of said input-output transistors, the emitters of said NPN transistors and said word line are merged into the same N-type semiconductor region.
Claim 8
Dependent Claim
30 words
The cell defined in claim 2 wherein the collector of each said input-output transistor and the base of a respective NPN transistor are merged into the same P-type semiconductor region.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |