Invalidity dossier
US 5525917
Sense amplifier with feedback and stabilization
Current assignee: Altera Corp
Added 9/21/2026, 9:37:48 AM
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Patent summary
Title, assignee, inventors, filing/issue dates, abstract, and a plain-language overview of the claims.
Patent Overview — US5525917A
Title: Sense amplifier with feedback and stabilization
Patent number: US5525917A
Application number: US08/358,210
Inventors: Myron W. Wong, Dirk A. Reese, John C. Costello
Assignee: Altera Corp (original assignee); later assignment recorded to Altera Corporation (a corporation of Delaware)
Priority/filing date: 1994-12-16
Publication (grant) date: 1996-06-11
Status listed: Expired – Fee Related; anticipated expiration 2014-12-16
Classification: G11C7/067 — Single-ended amplifiers (G11C7/06, sense amplifiers; associated circuits)
Purpose and plain-language scope. The patent relates to programmable logic devices (PLDs) and, more particularly, to bit line sense amplifiers used to read the interconnection state of a programmable array. The array is described as programmable interconnect elements (typically EPROMs, EEPROMs, or UVEPROMs) arranged along bit lines and word lines; a sense amplifier is provided for each bit line. If no connected EPROM conducts ("OFF"), the sense amplifier indicates a high output; if any conducts ("ON"), it pulls the bit line low, giving a low output. The disclosed sense amplifier uses feedback to bias the drain-line/source-line voltage difference closer to the trip voltage, speeding transitions, while feedback stabilization addresses reduced immunity to transistor processing variations and switching noise; a low power mode stops the feedback and stabilization circuitry from conducting at the cost of slower switching. In a first preferred embodiment, the amplifier includes a signal node, feedback node, output node, first and second voltage inverters, six variable current limiters, and a variable pull-up, with example potentials of about 1.2 V (drain line), 0.2 V (source line), 0.75 V (signal node), 4.5 V (supply), and 0.2 V cited.
Source: https://patents.google.com/patent/[US5525917](/patent/US5525917)/en
What the excerpt does not establish. The supplied text is excerpted and truncated mid-description; it does not include the complete specification, full claims, drawings, prior-art references, or the full list of cited art. Accordingly, claim scope, claim count, dependencies, and specific claim language cannot be stated from this excerpt. The excerpt also contains statements about expiration and assignment that Google Patents labels as assumptions, not legal conclusions.
Generated 10/1/2026, 10:01:59 PM
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Litigation summary
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Proceedings on file (0)
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PTAB challenges
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Assignment history
Inventors, original assignee, and the chain of ownership recorded with the USPTO — including the correspondent attorney who recorded each assignment, since shell-LLC chains often share one repeat-player attorney even when the entity names look unrelated. Surfaces NPE / patent-troll patterns: shell-entity transfers, known asserters in the chain, repeat correspondent fingerprints, pre-litigation assignments, and bankruptcy fire-sales.
Prior art
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Obviousness
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Extensions
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Derivative works
Defensive disclosure: derivative variations of each claim designed to render future incremental improvements obvious or non-novel.