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US5953249A Expired / Lapsed US ⏱️ 0.0 years remaining

Memory cell having negative differential resistance devices

Assignee: Texas Instruments Inc
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Filing: 1998-12-11
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Granted: 1999-09-14
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Expires: 2018-12-11
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Abstract

Abstract A memory system is organized as a matrix including a memory cell at each intersection of a bit line with write and read word lines. Each memory cell comprises a first FET 20 having its gate coupled to a write word line and its drain coupled to a bit line, a second FET 22 having its source coupled to the bit line and its drain coupled to a read word line, and first and second negative resistnce devices 24,26 coupled in series between a supply voltage and a substrate voltage, the common point SN of the series-connected negative resistance devices being coupled to the source of the first FET and to the gate of the second FET. Preferably, the first FET 20 is a p-channel device, the second FET 22 is an n-channel device, and the first and second negative resistance devices 24,26 are RTDs. In a second embodiment, a memory system has a memory cell at each intersection of a bit line with a word line. The memory cell comprises an FET having its gate coupled to a word line and one of its drain and source electrodes coupled to a bit line, first and second negative resistance devices 44,46 coupled in series between a supply voltage and a substrate voltage, the common point SN of the series-connected negative resistance devices being coupled to the other of the drain and source electrodes, and a capacitance 48 coupled between the common point of the series-connected negative resistance devices.

Inventors

  • 👤 Jan P. van der Wagt

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 03:13
CPC Classifications
B; B82; B82Y; B82Y10/00; G; G11; G11C; G11C5/00; G11C5/14; G11C5/142; G11C11/00; G11C11/21; G11C11/34; G11C11/39; G11C11/56; G11C2211/00; G11C2211/56; G11C2211/561; G11C2211/5614

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 113 words
In a memory system organized as a matrix including a memory cell at each intersection of a bit line with a word line, said memory cell comprising: a field effect transistor (FET) having its gate electrode coupled to a word line and one of its drain and source electrodes coupled to a bit line; first and second negative resistance devices coupled in series between a supply voltage and a substrate voltage, the common point of said series-connected negative resistance devices being coupled to the other of said drain and source electrodes; and a capacitance coupled between said common point of said series-connected negative resistance devices and one of said supply and substrate voltages.
Claim 2
Dependent Claim 113 words
In a memory system organized as a matrix including a memory cell at each intersection of a bit line with a word line, said memory cell comprising: a field effect transistor (FET) having its gate electrode coupled to a word line and one of its drain and source electrodes coupled to a bit line; first and second negative resistance devices coupled in series between a supply voltage and a substrate voltage, the common point of said series-connected negative resistance devices being coupled to the other of said drain and source electrodes; and a capacitance coupled between said common point of said series-connected negative resistance devices and one of said supply and substrate voltages.
Claim 3
Dependent Claim 15 words
The memory cell in accordance with claim 1 wherein said FET is an n-channel FET.
Claim 4
Dependent Claim 21 words
The memory cell in accordance with claim 1 wherein said first and second negative resistance devices are resonant tunneling diodes (RTDs).

References Cited (Backward Citations)

US5389804A Cited
US4902912A Cited
US5229623A Cited
US5093699A Cited
US5313117A Cited
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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) 2002-09-13 2003-03-15 2003-09-14 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2006-09-13 2007-03-15 2007-09-14 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2010-09-13 2011-03-15 2011-09-14 $7700.00 Window Closed / Lapsed

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