EP0412837A2
Expired / Lapsed
EP
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Ultraviolet erasable non-volatile memory devices
Assignee: Sony Corp
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Filing: 1990-08-10
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Granted: —
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Expires: 2010-08-10
Abstract
Abstract An ultraviolet erasable non-volatile memory device comprises a plurality of memory cells (10) which are erasable by ultraviolet rays and employs a sensing amplifier including a current mirror circuit (14, 15) connected to the memory cells (10) and a reference cell (11) respectively for read-out. In one example, an effective control gate voltage of the reference cell (11) is set to a lower value than that of the memory cells (10. The current drivability of the reference cell exhibits an intermediate value between that of an erased memory cell (10 and that of a programmed memory cell (10). In another example, a constant current source (32) is provided at a node (36) between the memory cells (10) and the current mirror circuit (14, 15), so that a current on the reference cell side is subtracted by the constant current source (32).
Inventors
- 👤 Hideki C/O Patents Divison Arakawa
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 10:45
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C16/26; G11C16/28; G11C16/10; G11C16/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
130 words
An ultraviolet erasable non-volatile memory device comprising: a plurality of memory cells (10) for storing information, said memory cells (10) being erasable by ultraviolet rays; a reference cell (11) having the same structure as said memory cells (10), said reference cell (11), being erasable by ultraviolet rays; a sensing amplifier having a current mirror circuit (14, 15), one node (16) of said current mirror circuit (14, 15) being connected to said memory cells (10), the other node of said current mirror circuit (14, 15) being connected to said reference cell (11); means (19) for selecting said memory cells (10) by a signal which has a predetermined voltage; and means (12, 13) for driving said reference cell (11) by a signal, said signal having a voltage lower than said predetermined voltage.
Claim 2
Dependent Claim
130 words
An ultraviolet erasable non-volatile memory device comprising: a plurality of memory cells (10) for storing information, said memory cells (10) being erasable by ultraviolet rays; a reference cell (11) having the same structure as said memory cells (10), said reference cell (11), being erasable by ultraviolet rays; a sensing amplifier having a current mirror circuit (14, 15), one node (16) of said current mirror circuit (14, 15) being connected to said memory cells (10), the other node of said current mirror circuit (14, 15) being connected to said reference cell (11); means (19) for selecting said memory cells (10) by a signal which has a predetermined voltage; and means (12, 13) for driving said reference cell (11) by a signal, said signal having a voltage lower than said predetermined voltage.
Claim 3
Dependent Claim
57 words
A device according to claim 1 wherein said memory cells (10) and said reference cell (11) have a field effect transistor structure comprising a floating gate and a control gate stacked through insulating films, and said signals provided by said means (19) for selecting and said means (12, 13) for driving are supplied to said control gates.
Claim 4
Dependent Claim
32 words
A device according to claim 2 wherein said memory cells (10) are arranged in a two-dimensional matrix array of rows and columns, and said means (19) for selecting is a row decoder.
Claim 5
Dependent Claim
82 words
A device according to claim 1, claim 2 or claim 3 wherein said means (12, 13) for driving comprises an nMOS transistor (12) and a pMOS transistor (13), a drain and a gate of said nMOS transistor (12) being supplied with a power supply voltage, and a drain and a gate of said pMOS transistor (13) being supplied with earth potential, the sources of said nMOS transistor (12) and said pMOS transistor (13) being connected to said reference cell (11) in common.
Claim 6
Dependent Claim
113 words
An ultraviolet erasable non-volatile memory device comprising: a plurality of memory cells (30) for storing information, said memory cells (30) being erasable by ultraviolet rays; a reference cell (31) having the same structure as said memory cells (30), said reference cell (31) being erasable by ultraviolet rays; a sensing amplifier having a current mirror circuit (34, 35), one node (36) of said current mirror circuit (34, 35) being connected to said memory cells (30), the other node of said current mirror circuit (34, 35) being connected to said reference cell (31); a constant current source (32) connected to a node (36) between said memory cells (30) and said current mirror circuit (34, 35).
Claim 7
Dependent Claim
113 words
An ultraviolet erasable non-volatile memory device comprising: a plurality of memory cells (30) for storing information, said memory cells (30) being erasable by ultraviolet rays; a reference cell (31) having the same structure as said memory cells (30), said reference cell (31) being erasable by ultraviolet rays; a sensing amplifier having a current mirror circuit (34, 35), one node (36) of said current mirror circuit (34, 35) being connected to said memory cells (30), the other node of said current mirror circuit (34, 35) being connected to said reference cell (31); a constant current source (32) connected to a node (36) between said memory cells (30) and said current mirror circuit (34, 35).
Claim 8
Dependent Claim
19 words
A device according to claim 5 wherein said constant current source (52) is a depletion type MOS transistor (52).
Claim 9
Dependent Claim
48 words
A device according to claim 5 wherein an inverter (57) connected to said node (56) amplifies the potential at said node (56), and a input terminal and a output terminal of said inverter (57) are connected each other by a switching means (58) before a data outputting operation.
References Cited (Backward Citations)
No citation records indexed.
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