US6323671B1
Expired / Lapsed
US
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Charge gain stress test circuit for nonvolatile memory and test method using the same
Assignee: SK Hynix Inc
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Filing: 1999-04-15
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Granted: 2001-11-27
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Expires: 2019-04-15
Abstract
Abstract A charge gain stress test circuit for a nonvolatile memory and a test method using the same according to the present invention allow a maximum size of a voltage used for a stress lower than a voltage applied in a normal operation. The preferred embodiment sufficiently increases an absolute value of an applicable stress voltage by using a reference current to control a stress voltage value without burdening the peripheral circuits. The preferred embodiment optimizes a stress time, namely the test time.
Inventors
- 👤 Kyeong-Man Ra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 17:57
CPC Classifications
G; G11; G11C; G11C16/00; G11C16/02; G11C16/06; G11C29/00; G11C29/04; G11C29/50; G11C16/04; G11C2029/5006
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
162 words
A circuit for performing a -charge gain stress test for a nonvolatile memory having plurality of cells, comprising: a reference current generator that generates a reference current; a comparator that compares a cell current from a selected one of the nonvolatile memory cells with the reference current and outputting a compare result; a first switch controlled by a first control signal to selectively connect the comparator or a first voltage to a drain of the selected nonvolatile memory cell; a second switch controlled by the first control signal to selectively connect the first voltage or a second voltage to a gate of the selected nonvolatile memory cell, or controlled by a second control signal to selectively connect the first voltage or a third voltage to the gate of the selected nonvolatile memory cell; and a third switch controlled by the second control signal to selectively connect the first voltage or a fourth voltage to a source of the selected nonvolatile memory cell.
Claim 2
Dependent Claim
162 words
A circuit for performing a -charge gain stress test for a nonvolatile memory having plurality of cells, comprising: a reference current generator that generates a reference current; a comparator that compares a cell current from a selected one of the nonvolatile memory cells with the reference current and outputting a compare result; a first switch controlled by a first control signal to selectively connect the comparator or a first voltage to a drain of the selected nonvolatile memory cell; a second switch controlled by the first control signal to selectively connect the first voltage or a second voltage to a gate of the selected nonvolatile memory cell, or controlled by a second control signal to selectively connect the first voltage or a third voltage to the gate of the selected nonvolatile memory cell; and a third switch controlled by the second control signal to selectively connect the first voltage or a fourth voltage to a source of the selected nonvolatile memory cell.
Claim 3
Dependent Claim
15 words
The circuit of claim 1 , wherein the first voltage is a ground source voltage.
Claim 4
Dependent Claim
21 words
The circuit of claim 1 , wherein the second voltage is used for applying a stress to the nonvolatile memory cell.
Claim 5
Dependent Claim
20 words
The circuit of claim 1 , wherein the third voltage is used for erasing data of the nonvolatile memory cell.
Claim 6
Dependent Claim
20 words
The circuit of claim 1 , wherein the fourth voltage is used for erasing data of the nonvolatile memory cell.
Claim 7
Dependent Claim
13 words
The circuit of claim 1 , wherein said comparator is a sense amp.
Claim 8
Dependent Claim
16 words
The circuit of claim 1 , wherein the nonvolatile memory cell is a flash memory cell.
References Cited (Backward Citations)
US5745412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2004-11-26 | 2005-05-28 | 2005-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-11-26 | 2009-05-28 | 2009-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-11-26 | 2013-05-28 | 2013-11-27 | $7700.00 | Window Closed / Lapsed |