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US4779230A Expired / Lapsed US ⏱️ 0.0 years remaining

CMOS static ram cell provided with an additional bipolar drive transistor

Assignee: NXP USA Inc
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Filing: 1986-12-29
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Granted: 1988-10-18
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Expires: 2006-12-29
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Abstract

Abstract A BIMOS memory cell is formed by providing a CMOS static RAM cell with an additional NPN bipolar transistor to provide additional drive current during the read cycle to improve the read time of the memory cell.

Inventors

  • 👤 Kevin L. McLaughlin
  • 👤 Walter C. Seelbach

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 02:34
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/34; G11C11/40; G11C11/41

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 332 words
A memory cell comprising: first, second, third and fourth transistors each having a control terminal and first and second load terminals, said first load terminal of said first and second transistors coupled together for connection to a first word line terminal, said first load terminals of said third and fourth transistors coupled together for connection to a second word line terminal; a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal, said control terminal of said fifth transistor coupled to said second load terminals of said second and fourth transistors and s aid second load terminal of said fifth transistor for coupling to a first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said first, third and fifth transistors and said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor; a seventh transistor having a control terminal and first and second load terminals, said first load terminal of said seventh transistor coupled to said first word line terminal, said control terminal of said seventh transistor coupled to said second load terminals of said first and third transistors and said second load terminal of said seventh transistor coupled to a complemented first bit line; an eighth transistor having a control terminal and first and second load terminals, said first load terminal of said eighth transistor coupled to the control terminals of said second, fourth and seventh transistors, said second load terminal of said eighth transistor coupled to said second load terminal of said seventh transistor and said control terminals of said sixth and eighth transistors for coupling to a write enable terminal; and wherein said first, second, third, fourth, sixth and eighth transistors are field effect transistors and said fifth and seventh transistors are bipolar transistors.
Claim 2
Dependent Claim 332 words
A memory cell comprising: first, second, third and fourth transistors each having a control terminal and first and second load terminals, said first load terminal of said first and second transistors coupled together for connection to a first word line terminal, said first load terminals of said third and fourth transistors coupled together for connection to a second word line terminal; a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal, said control terminal of said fifth transistor coupled to said second load terminals of said second and fourth transistors and s aid second load terminal of said fifth transistor for coupling to a first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said first, third and fifth transistors and said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor; a seventh transistor having a control terminal and first and second load terminals, said first load terminal of said seventh transistor coupled to said first word line terminal, said control terminal of said seventh transistor coupled to said second load terminals of said first and third transistors and said second load terminal of said seventh transistor coupled to a complemented first bit line; an eighth transistor having a control terminal and first and second load terminals, said first load terminal of said eighth transistor coupled to the control terminals of said second, fourth and seventh transistors, said second load terminal of said eighth transistor coupled to said second load terminal of said seventh transistor and said control terminals of said sixth and eighth transistors for coupling to a write enable terminal; and wherein said first, second, third, fourth, sixth and eighth transistors are field effect transistors and said fifth and seventh transistors are bipolar transistors.
Claim 3
Dependent Claim 26 words
The memory cell of claim 1 wherein said first and second transistors are p-channel transistors and said third, fourth, sixth and eighth transistors are n-channel transistors.
Claim 4
Dependent Claim 15 words
The memory cell of claim 2 wherein said fifth and seventh transistors are NPN transistors.
Claim 5
Dependent Claim 42 words
The memory cell of claim 2 wherein said control terminals of said first, second, third and fourth transistors are gate terminals and said first and second load terminals of said first, second, third and fourth transistors are source and drain terminals, respectively.
Claim 6
Dependent Claim 24 words
The memory cell of claim 2 wherein said first, second, third, fourth, fifth, sixth, seventh and eighth transistors are contained in an integrated circuit.
Claim 7
Dependent Claim 26 words
The memory cell of claim 5 wherein said fifth and seventh transistors are respectively merged with the second load terminals of said second and first transistors.
Claim 8
Dependent Claim 402 words
In a memory cell comprising: first, second third and fourth transistors, each having a control terminal and first and second load terminals, said first load terminals of said first and second transistors coupled together for connection to a first word line terminal, said first load terminals of said third and fourth transistors coupled together for connection to a second word line terminal, said control terminals of said first and third transistors coupled together and coupled to said second load terminals of said second and fourth transistors for coupling to a first bit line, and said control terminals of said second and fourth transistors coupled together and to said second load terminals of said first and third transistors for coupling to a complemented first bit line, the improvement comprising: a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal, said control terminal of said fifth transistor coupled to said second load terminals of said second and fourth transistors and said second load terminal of said fifth transistor for coupling to a first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said first, third and fifth transistors and said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor; a seventh transistor having a control terminal and first and second load terminals, said first load terminal of said seventh transistor coupled to said first word line terminal, said control terminal of said seventh transistor coupled to said second load terminals of said first and third transistors and said second load terminal of said seventh transistor coupled to a complemented first bit line; an eighth transistor having a control terminal and first and second load terminals, said first load terminal of said eighth transistor coupled to the control terminals of said second, fourth and seventh transistors, said second load terminal of said eighth transistor coupled to said second load terminal of said seventh transistor and said control terminals of said control terminals of said sixth and eighth transistors for coupling to a write enable terminal; and wherein said first, second third, fourth sixth and eighth transistors are field effect transistors and said fifth and seventh transistors are bipolar transistors.
Claim 9
Dependent Claim 402 words
In a memory cell comprising: first, second third and fourth transistors, each having a control terminal and first and second load terminals, said first load terminals of said first and second transistors coupled together for connection to a first word line terminal, said first load terminals of said third and fourth transistors coupled together for connection to a second word line terminal, said control terminals of said first and third transistors coupled together and coupled to said second load terminals of said second and fourth transistors for coupling to a first bit line, and said control terminals of said second and fourth transistors coupled together and to said second load terminals of said first and third transistors for coupling to a complemented first bit line, the improvement comprising: a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal, said control terminal of said fifth transistor coupled to said second load terminals of said second and fourth transistors and said second load terminal of said fifth transistor for coupling to a first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said first, third and fifth transistors and said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor; a seventh transistor having a control terminal and first and second load terminals, said first load terminal of said seventh transistor coupled to said first word line terminal, said control terminal of said seventh transistor coupled to said second load terminals of said first and third transistors and said second load terminal of said seventh transistor coupled to a complemented first bit line; an eighth transistor having a control terminal and first and second load terminals, said first load terminal of said eighth transistor coupled to the control terminals of said second, fourth and seventh transistors, said second load terminal of said eighth transistor coupled to said second load terminal of said seventh transistor and said control terminals of said control terminals of said sixth and eighth transistors for coupling to a write enable terminal; and wherein said first, second third, fourth sixth and eighth transistors are field effect transistors and said fifth and seventh transistors are bipolar transistors.
Claim 10
Dependent Claim 26 words
The memory cell of claim 7 wherein said first and second transistors are p-channel transistors and said third, fourth, sixth and eighth transistors are n-channel transistors.
Claim 11
Dependent Claim 24 words
The memory cell of claim 8 wherein said first, second, third, fourth, fifth, sixth, seventh and eighth transistors are contained in an integrated circuit.
Claim 12
Dependent Claim 25 words
The circuit of claim 9 wherein said first and seventh transistors are respectively merged into the second load terminals of said second and first transistors.
Claim 13
Dependent Claim 313 words
A memory cell comprising: first and second resistors and first and second transistors, each of said transistors having a control terminal and first and second load terminals, said first load terminals of said first and second transistors coupled together for connection to a first word line terminal and said second load terminals of said first and second transistors respectively coupled to one end of said first and second resistors, the other ends of said first and second resistors coupled to a second word line terminal; a third transistor having a control terminal and first and second load terminals, said first load terminal of said third transistor coupled to said first word line terminal and said second load terminal of said third transistor for coupling to a first bit line; a fourth transistor having a control terminal and first and second load terminals, said first load terminal of said fourth transistor coupled to the control terminals of said first and third transistors and said second load terminal of said fourth transistor coupled to said second load terminal of said third transistor; a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal and said second load terminal of said fifth transistor coupled to a complemented first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said second and fifth transistors, said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor and said control terminals of said fourth and sixth transistors for coupling to a write enable terminal; and wherein said first, second, fourth and sixth transistors are field effect transistors and said third and fifth transistors are bipolar transistors.
Claim 14
Dependent Claim 313 words
A memory cell comprising: first and second resistors and first and second transistors, each of said transistors having a control terminal and first and second load terminals, said first load terminals of said first and second transistors coupled together for connection to a first word line terminal and said second load terminals of said first and second transistors respectively coupled to one end of said first and second resistors, the other ends of said first and second resistors coupled to a second word line terminal; a third transistor having a control terminal and first and second load terminals, said first load terminal of said third transistor coupled to said first word line terminal and said second load terminal of said third transistor for coupling to a first bit line; a fourth transistor having a control terminal and first and second load terminals, said first load terminal of said fourth transistor coupled to the control terminals of said first and third transistors and said second load terminal of said fourth transistor coupled to said second load terminal of said third transistor; a fifth transistor having a control terminal and first and second load terminals, said first load terminal of said fifth transistor coupled to said first word line terminal and said second load terminal of said fifth transistor coupled to a complemented first bit line; a sixth transistor having a control terminal and first and second load terminals, said first load terminal of said sixth transistor coupled to the control terminals of said second and fifth transistors, said second load terminal of said sixth transistor coupled to said second load terminal of said fifth transistor and said control terminals of said fourth and sixth transistors for coupling to a write enable terminal; and wherein said first, second, fourth and sixth transistors are field effect transistors and said third and fifth transistors are bipolar transistors.
Claim 15
Dependent Claim 24 words
The memory cell of claim 11 wherein said first and second transistors are p-channel transistors and said fourth and sixth transistors are n-channel transistors.
Claim 16
Dependent Claim 22 words
The memory cell of claim 12 wherein said first, second, third, fourth, fifth and sixth transistors are contained in an integrated circuit.
Claim 17
Dependent Claim 25 words
The circuit of claim 13 wherein said third and fifth transistors are respectively merged into the second load terminals of said second and first transistors.

References Cited (Backward Citations)

US3553541A Cited
US4701883A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-10-18 1992-04-18 1992-10-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-10-18 1996-04-18 1996-10-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-10-18 2000-04-18 2000-10-18 $7700.00 Window Closed / Lapsed

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