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US5847987A Expired / Lapsed US ⏱️ 0.0 years remaining

Low currency redundancy anti-fuse method and apparatus

Assignee: Micron Technology Inc
•
Filing: 1997-07-18
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Granted: 1998-12-08
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Expires: 2017-07-18
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Abstract

Abstract A programmable circuit includes a first node and provides a programmed signal based on the state of the first node. A first anti-fuse has a programmed state and an unprogrammed state and couples the first node to a first power supply when in the programmed state and decouples the first node from the first power supply when in the unprogrammed state. A second anti-fuse has a programmed state and an unprogrammed state and couples the first node to a second power supply when in the programmed state and decouples the first node from the second power supply when in the unprogrammed state. The state of the programmed signal can be used to replace a primary circuit element of an integrated circuit with a redundant circuit element.

Inventors

  • 👤 Douglas J. Cutter
  • 👤 Kurt D. Beigel
  • 👤 Fan Ho

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 10:52
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/70; G11C29/78; G11C29/785; G11C17/00; G11C17/14; G11C17/18; G11C29/83

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 256 words
A programmable circuit coupled to a first power supply and a second power supply for providing a programmed signal in an integrated circuit comprising: a first node, wherein the state of the programmed signal is based on the state of the first node; a first anti-fuse including a first terminal coupled to the first node and a second terminal coupled to the first power supply; a second anti-fuse including a first terminal coupled to the first node and a second terminal coupled to the first power supply; a first programming bus carrying a sufficient voltage to short the first anti-fuse; a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to the first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programing bus during a first programming operation of the integrated circuit for programming the first anti-fuse to couple the first node to the first power supply; a second programming bus carrying a sufficient voltage to short the second anti-fuse; and a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to the second power supply during normal operation of the integrated circuit and coupling the second terminal of the second anti-fuse to the second programing bus during a second programming operation of the integrated circuit for programming the second anti-fuse to couple the first node to the second power supply.
Claim 2
Dependent Claim 256 words
A programmable circuit coupled to a first power supply and a second power supply for providing a programmed signal in an integrated circuit comprising: a first node, wherein the state of the programmed signal is based on the state of the first node; a first anti-fuse including a first terminal coupled to the first node and a second terminal coupled to the first power supply; a second anti-fuse including a first terminal coupled to the first node and a second terminal coupled to the first power supply; a first programming bus carrying a sufficient voltage to short the first anti-fuse; a first switch coupled to the second terminal of the first anti-fuse for coupling the second terminal of the first anti-fuse to the first power supply during normal operation of the integrated circuit and coupling the second terminal of the first anti-fuse to the first programing bus during a first programming operation of the integrated circuit for programming the first anti-fuse to couple the first node to the first power supply; a second programming bus carrying a sufficient voltage to short the second anti-fuse; and a second switch coupled to the second terminal of the second anti-fuse for coupling the second terminal of the second anti-fuse to the second power supply during normal operation of the integrated circuit and coupling the second terminal of the second anti-fuse to the second programing bus during a second programming operation of the integrated circuit for programming the second anti-fuse to couple the first node to the second power supply.
Claim 3
Dependent Claim 66 words
The programmable circuit of claim 1 further comprising: a switch coupled between the second power supply and the first node and responsive to at least one programming control signal received by the programmable circuit, wherein the switch is closed to couple the first node to the second power supply during a programming operation of the integrated circuit and open during normal operations of the integrated circuit.
Claim 4
Dependent Claim 12 words
The programmable circuit of claim 2 wherein the switch comprises a transistor.
Claim 5
Dependent Claim 72 words
The programmable circuit of claim 1 further comprising: a switch coupled between the second power supply and the first node and responsive to an enable signal received by the programming circuit, wherein the switch is closed to couple the first node to the second power supply based on the enable signal being in a first state, and wherein the switch is open based on the enable signal being in a second state.
Claim 6
Dependent Claim 12 words
The programmable circuit of claim 4 wherein the switch comprises a transistor.
Claim 7
Dependent Claim 15 words
The programmable circuit of claim 1 wherein the second power supply comprises a ground node.

References Cited (Backward Citations)

US5243226A Cited
US5264725A Cited
US5315177A Cited
US5424672A Cited
US5508638A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-12-07 2002-06-08 2002-12-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-12-07 2006-06-08 2006-12-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-12-07 2010-06-08 2010-12-08 $7700.00 Window Closed / Lapsed

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