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US4733372A Expired / Lapsed US ⏱️ 0.0 years remaining

Semiconductor memory having redundancy

Assignee: Hitachi Ltd
•
Filing: 1986-08-06
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Granted: 1988-03-22
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Expires: 2006-08-06
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Abstract

Abstract Herein disclosed is a bipolar memory having redundancy, which can be produced with a small area. In this semiconductor memory having a body memory for storing data and a spare memory for relief of fault bit of the body memory, a row is selected by cutting fuses in a decoder. Fundamentally signal lines such as word lines are not provided with fuses. Other parts including a power source and a reference voltage source are provided with fuses without decreasing the operating speed accompanied by only a slight increase in the area.

Inventors

  • 👤 Hiroaki Nanbu
  • 👤 Kunihiko Yamaguchi
  • 👤 Noriyuki Honma
  • 👤 Kazuo Kanetani
  • 👤 Motoaki Matumoto
  • 👤 Kazuhiko Tani
  • 👤 Kenichi Ohata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 05:44
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/70; G11C29/78; G11C29/80; G11C29/83; G11C29/832; G11C29/84

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 158 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having their bases made receptive of said address signal; third and fourth bipolar transistors having their emitter electrodes connected with the emitters of the first and second bipolar transistors and their bases made receptive of a reference voltage; and a current source having fuses connected with said emitter electrodes, respectively, so that a redundancy row selection signal may be outputted from the collectors of said first and third bipolar transistors or said second and fourth bipolar transistors, whereby said fuses are cut so that the selection signal may be outputted when said address signal indicates the address of a fault row.
Claim 2
Dependent Claim 158 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having their bases made receptive of said address signal; third and fourth bipolar transistors having their emitter electrodes connected with the emitters of the first and second bipolar transistors and their bases made receptive of a reference voltage; and a current source having fuses connected with said emitter electrodes, respectively, so that a redundancy row selection signal may be outputted from the collectors of said first and third bipolar transistors or said second and fourth bipolar transistors, whereby said fuses are cut so that the selection signal may be outputted when said address signal indicates the address of a fault row.
Claim 3
Dependent Claim 27 words
A bipolar memory according to claim 1, wherein said current source having fuses further has fifth and sixth bipolar transistors having their bases connected with said fuses.
Claim 4
Dependent Claim 23 words
A bipolar memory according to claim 2, wherein resistors are connected between the bases and emitters of said fifth and sixth bipolar transistors.
Claim 5
Dependent Claim 14 words
A bipolar memory according to claim 3, wherein said fuses are made of poly-silicon.
Claim 6
Dependent Claim 27 words
A bipolar memory according to claim 1, wherein said current source having fuses further has fifth and sixth bipolar transistors having their emitters connected with said fuses.
Claim 7
Dependent Claim 23 words
A bipolar memory according to claim 5, wherein resistors are connected between the bases and emitters of said fifth and sixth bipolar transistors.
Claim 8
Dependent Claim 41 words
A bipolar memory according to claim 1, wherein said current source having fuses further has fifth and sixth bipolar transistors such that fuses are connected in series with resistors between the bases and emitters of said fifth and sixth bipolar transistors.
Claim 9
Dependent Claim 37 words
A bipolar memory according to claim 1, wherein said current source having fuses further has fifth and sixth bipolar transistors having their bases connected with fuses and further their emitters connected with a common internal current source.
Claim 10
Dependent Claim 14 words
A bipolar memory according to claim 8, wherein said fuses are made of poly-silicon.
Claim 11
Dependent Claim 180 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having at least their bases made receptive of said address signal corresponding to an address number; a third bipolar transistor having its emitter electrode connected with the emitters of the first and second bipolar transistors and its base made receptive of a reference voltage; and a current source connected with the emitters of said first, second and third bipolar transistors and the bases or emitters of said first and second or third bipolar transistor are provided with fuses so that the redundancy row selection signal may be outputted from the collectors of said first, second and third bipolar transistors, whereby said fuses are cut so that said selection signal may be outputted when said address signal indicates the address of a fault row.
Claim 12
Dependent Claim 180 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having at least their bases made receptive of said address signal corresponding to an address number; a third bipolar transistor having its emitter electrode connected with the emitters of the first and second bipolar transistors and its base made receptive of a reference voltage; and a current source connected with the emitters of said first, second and third bipolar transistors and the bases or emitters of said first and second or third bipolar transistor are provided with fuses so that the redundancy row selection signal may be outputted from the collectors of said first, second and third bipolar transistors, whereby said fuses are cut so that said selection signal may be outputted when said address signal indicates the address of a fault row.
Claim 13
Dependent Claim 33 words
A bipolar memory according to claim 10, wherein said fuses are made of poly-silicon, and wherein resistors are connected between the bases and emitters of said first and second or third bipolar transistors.
Claim 14
Dependent Claim 17 words
A bipolar memory according to claim 11, wherein said fault row is equipped with voltage stabilization means.
Claim 15
Dependent Claim 25 words
A bipolar memory according to claim 11, wherein said fault row is isolated from the row selection means and is equipped with voltage stabilization means.
Claim 16
Dependent Claim 187 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having their bases made receptive of said address signal; third and fourth bipolar transistors having their emitter electrodes connected with the emitters of the first and second bipolar transistors and their bases made receptive of a reference voltage; and a current source having fuses connected with said emitter electrodes, respectively, so that a redundancy row selection signal may be outputted from the collectors of said first and third bipolar transistors or said second and fourth bipolar transistors, wherein said fault row is isolated from said row selection means, wherein said fault row is equipped with voltage stabilization means, and wherein said fuses are made of poly-silicon, whereby said fuses are cut so that the selection signal may be outputted when said address signal indicates the address of a fault row.7
Claim 17
Dependent Claim 187 words
A bipolar memory having redundancy, comprising: a memory array including bipolar memory cells; a redundancy row including at least one row of memory cells; an address buffer made receptive of an address signal; decoder means made receptive of said address signal for selecting said memory array; and redundancy row selecting means including: first and second bipolar transistors having their bases made receptive of said address signal; third and fourth bipolar transistors having their emitter electrodes connected with the emitters of the first and second bipolar transistors and their bases made receptive of a reference voltage; and a current source having fuses connected with said emitter electrodes, respectively, so that a redundancy row selection signal may be outputted from the collectors of said first and third bipolar transistors or said second and fourth bipolar transistors, wherein said fault row is isolated from said row selection means, wherein said fault row is equipped with voltage stabilization means, and wherein said fuses are made of poly-silicon, whereby said fuses are cut so that the selection signal may be outputted when said address signal indicates the address of a fault row.7

References Cited (Backward Citations)

US3872450A Cited
US4101974A Cited
US4586169A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1991-03-22 1991-09-21 1992-03-22 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1995-03-22 1995-09-21 1996-03-22 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1999-03-22 1999-09-21 2000-03-22 $7700.00 Window Closed / Lapsed

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