Patent EP0359404A2 successfully refreshed from Google Patents.
EP0359404A2
Expired / Lapsed
EP
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Non-volatile memory cell and sensing method
Assignee: Ramtron International Corp
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Filing: 1989-08-15
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Granted: —
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Expires: 2009-08-15
Abstract
Abstract A ferroelectric memory cell (10) has one capacitor (12) isolated from bit lines (14,16) by two transistors (18,20), one on each side. The cell is read by pulsing the capacitor in one direction, then the other, storing developed charge on other capacitors or the like, and comparing voltages.
Inventors
- 👤 Kenneth Mobley
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 02:25
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/21; G11C11/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
48 words
A non-volatile memory cell comprising a ferroelectric capacitor, a first bit line, a first switching device coupling one plate of said capacitor to said first bit line, a second bit line, and a second switching device coupling the other plate of said capacitor to said second bit line.
Claim 2
Dependent Claim
48 words
A non-volatile memory cell comprising a ferroelectric capacitor, a first bit line, a first switching device coupling one plate of said capacitor to said first bit line, a second bit line, and a second switching device coupling the other plate of said capacitor to said second bit line.
Claim 3
Dependent Claim
20 words
The cell of claim 1 further comprising a word line coupled to control both said first and second switching devices.
Claim 4
Dependent Claim
11 words
The cell of claim 2 wherein said switching devices comprise transistors.
Claim 5
Independent Claim
54 words
A method to read data stored in a non-volatile memory cell which uses a ferroelectric capacitor comprising the steps of applying a first pulse to said capacitor and storing a first resulting signal, applying a second pulse to the capacitor to develop a second resulting signal, and combining said first and second resulting signals.
Claim 6
Independent Claim
54 words
A method to read data stored in a non-volatile memory cell which uses a ferroelectric capacitor comprising the steps of applying a first pulse to said capacitor and storing a first resulting signal, applying a second pulse to the capacitor to develop a second resulting signal, and combining said first and second resulting signals.
Claim 7
Dependent Claim
15 words
The method of claim 4 wherein said storing step includes storing charge on a capacitor.
Claim 8
Dependent Claim
33 words
The method of claim 4 wherein said storing and developing steps include storing said first resulting signal on a first storage capacitor and storing said second resulting signal on a second storage capacitor.
Claim 9
Dependent Claim
30 words
The method of claim 4 wherein said first pulse is applied to said capacitor in a first polarity sense and said second pulse is applied in a second polarity sense.
Claim 10
Dependent Claim
48 words
The method of claim 7 wherein said first and second pulses each comprise voltage excursions of the same polarity but wherein one said pulse is applied to one plate of said ferroelectric capacitor and the other said pulse is applied to the other plate of said ferroelectric capacitor.
Claim 11
Dependent Claim
44 words
The method of claim 8 wherein said first pulse is applied via a first bit line coupled to one plate of said ferroelectric capacitor and said second pulse is applied via a second bit line coupled to the other plate of said ferroelectric capacitor.
Claim 12
Dependent Claim
51 words
The method of claim 9 wherein said method further includes isolating said ferroelectric capacitor from one storage device while coupling another storage device to said ferroelectric capacitor, and then isolating said ferroelectric capacitor from said another bit line and said another storage device while coupling it to said one storage device.
Claim 13
Dependent Claim
34 words
The method of claim 4 wherein said first pulse drives said ferroelectric capacitor along one portion of a hysteresis loop and said second pulse drives said capacitor along a different portion of said loop.
Claim 14
Independent Claim
109 words
A method of reading data stored in a non-volatile memory cell which uses a ferroelectric capacitor for storage, comprising the steps of: applying a first pulse to said ferroelectric capacitor and developing a signal on a first storage capacitor selectively coupled to said ferroelectric capacitor, while isolating said ferroelectric capacitor from a second storage capacitor; then applying a second pulse to said ferroelectric capacitor and developing a signal on a second storage capacitor selectively coupled to said ferroelectric capacitor while isolating said ferroelectric capacitor from said first storage capacitor; and combining signals from said first and second storage capacitors to determine the original polarization state of the ferroelectric capacitor.
Claim 15
Independent Claim
109 words
A method of reading data stored in a non-volatile memory cell which uses a ferroelectric capacitor for storage, comprising the steps of: applying a first pulse to said ferroelectric capacitor and developing a signal on a first storage capacitor selectively coupled to said ferroelectric capacitor, while isolating said ferroelectric capacitor from a second storage capacitor; then applying a second pulse to said ferroelectric capacitor and developing a signal on a second storage capacitor selectively coupled to said ferroelectric capacitor while isolating said ferroelectric capacitor from said first storage capacitor; and combining signals from said first and second storage capacitors to determine the original polarization state of the ferroelectric capacitor.
References Cited (Backward Citations)
No citation records indexed.
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