US4464590A
Expired / Lapsed
US
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Memory system current sense amplifier circuit
Assignee: National Semiconductor Corp
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Filing: 1982-06-23
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Granted: 1984-08-07
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Expires: 2002-06-23
Abstract
Abstract A current responsive sense amplifier circuit is used in a semiconductor memory. The circuit includes means for reducing the voltage swings that are associated with the binary logic states.
Inventors
- 👤 A. Karl Rapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:21
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/02; H03K5/023; H03K19/00; H03K19/01; H03K19/017
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
166 words
In a current sensing amplifier having an input terminal coupled to a memory element which is to have its memory content sensed and an output terminal which produces a voltage state indicative of said memory content, said amplifier comprising: a first inverter gate made up of an inverting transistor and a load transistor, having its output shorted to its input so that it operates at its trip point, and coupled to said input terminal to reduce the voltage swings thereof; a second inverter gate, made up of an inverting transistor and a load transistor, and having an input node coupled to said input terminal and an output node coupled to said output terminal; and first feedback means coupled between said second inverter gate input and output nodes; the improvement comprising; a noninverting buffer amplifier coupled in cascade with said second inverter gate output node to drive said output terminal; and second feedback means coupled between said output terminal and said input terminal of said sensing amplifier.
Claim 2
Dependent Claim
166 words
In a current sensing amplifier having an input terminal coupled to a memory element which is to have its memory content sensed and an output terminal which produces a voltage state indicative of said memory content, said amplifier comprising: a first inverter gate made up of an inverting transistor and a load transistor, having its output shorted to its input so that it operates at its trip point, and coupled to said input terminal to reduce the voltage swings thereof; a second inverter gate, made up of an inverting transistor and a load transistor, and having an input node coupled to said input terminal and an output node coupled to said output terminal; and first feedback means coupled between said second inverter gate input and output nodes; the improvement comprising; a noninverting buffer amplifier coupled in cascade with said second inverter gate output node to drive said output terminal; and second feedback means coupled between said output terminal and said input terminal of said sensing amplifier.
Claim 3
Dependent Claim
33 words
The improvement of claim 1 wherein said second feedback means is output voltage sensitive and becomes effective when said output voltage rises above said first inverter trip point plus an enhancement transistor threshold.
Claim 4
Dependent Claim
24 words
The improvement of claim 2 wherein said second feedback means comprise a feedback enhancement transistor coupled between said output terminal and said input terminal.
Claim 5
Dependent Claim
28 words
The improvement of claim 3 wherein said feedback enhancement transistor has its drain and gate coupled to said output terminal and its source coupled to said input terminal.
Claim 6
Dependent Claim
36 words
The improvement of claim 3 wherein said feedback enhancement transistor has its drain returned to a fixed source of supply potential, its source coupled to said input terminal, and its gate coupled to said output terminal.
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) | 1987-08-07 | 1988-02-06 | 1988-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-08-07 | 1992-02-06 | 1992-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-08-07 | 1996-02-06 | 1996-08-07 | $7700.00 | Window Closed / Lapsed |