US5396455A
Expired / Lapsed
US
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Magnetic non-volatile random access memory
Assignee: GlobalFoundries Inc
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Filing: 1993-04-30
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Granted: 1995-03-07
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Expires: 2013-04-30
Abstract
Abstract A non-volatile random access memory is described incorporating a plurality of memory cells, each memory cell having a Hall effect device including amorphous magnetic material and a switch for directing current through the flail effect device. An array of memory cells are interconnected by word lines, current lines, and bit lines. The invention overcomes the problem of a rugged non-volatile random access memory with long term reliability.
Inventors
- 👤 Michael J. Brady
- 👤 Richard J. Gambino
- 👤 Lia Krusin-Elbaum
- 👤 Ralph R. Ruf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:05
CPC Classifications
G; G11; G11C; G11C11/00; G11C11/18
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
167 words
A non-volatile random access memory comprising: a two dimensional array of Hall effect devices arranged in a plurality of rows and columns, each said Hall effect device having first and second spaced apart terminals for connecting in series with a current line, each said Hall effect device having third and fourth spaced apart terminals for connecting in series with a bit line, each Hall effect device in a respective column connected to a word line, each Hall effect device in a respective row connected in a respective current line and a respective bit line, the connection of each Hall effect device in a respective current line is through a switch, the word line is coupled to the control input of said switch, the magnetic state of the Hall effect device is sensed by measuring the voltage on the bit line when a current is passed through the Hall effect device by activating the current line and turning on the switch by a voltage on the word line.
Claim 2
Dependent Claim
167 words
A non-volatile random access memory comprising: a two dimensional array of Hall effect devices arranged in a plurality of rows and columns, each said Hall effect device having first and second spaced apart terminals for connecting in series with a current line, each said Hall effect device having third and fourth spaced apart terminals for connecting in series with a bit line, each Hall effect device in a respective column connected to a word line, each Hall effect device in a respective row connected in a respective current line and a respective bit line, the connection of each Hall effect device in a respective current line is through a switch, the word line is coupled to the control input of said switch, the magnetic state of the Hall effect device is sensed by measuring the voltage on the bit line when a current is passed through the Hall effect device by activating the current line and turning on the switch by a voltage on the word line.
Claim 3
Dependent Claim
26 words
The memory of claim 1 wherein said 1 Hall effect device is made of a thin film of a material exhibiting a large spontaneous Hall effect.
Claim 4
Dependent Claim
24 words
The memory of claim 1 wherein said Hall effect device is made of a magnetic material with a square magnetization loop and high remanence.
Claim 5
Dependent Claim
20 words
The memory of claim 1 wherein said Hall effect device is made of an amorphous magnetic material with perpendicular anisotropy.
Claim 6
Dependent Claim
17 words
The memory of claim 1 wherein said Hall effect device is made of a magnetic bubble material.
Claim 7
Dependent Claim
37 words
The memory of claim 1 wherein said Hall effect device is made of a doped semiconductor material and is provided with an adjacent square magnetization loop magnetic material which provides a magnetic field at the Hall device.
Claim 8
Dependent Claim
17 words
The memory of claim 1 wherein the magnetic state of the Hall effect device is written thermomagnetically.
Claim 9
Dependent Claim
33 words
The memory of claim 1 wherein the magnetic state of the Hall effect device is written by moving a magnetic bubble by means of a current pulse through the domain Hall effect device.
Claim 10
Dependent Claim
62 words
The memory of claim 1 wherein the magnetic state of the Hall effect device is read by applying a voltage on the word line of sufficient magnitude to turn on the switch, whereby the resulting current through the Hall effect device will produce a positive or negative Hall effect voltage on said bit line depending on magnetic state of the Hall device.
Claim 11
Dependent Claim
17 words
The memory of claim 9 wherein said bit line is coupled to one input of a comparator.
Claim 12
Dependent Claim
12 words
The memory of claim 1 wherein said switch is a MOS transistor.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-03-06 | 1998-09-05 | 1999-03-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-06 | 2002-09-05 | 2003-03-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-06 | 2006-09-05 | 2007-03-07 | $7700.00 | Window Closed / Lapsed |