US6310463B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Secondary battery cell protection circuit
Assignee: Mitsumi Electric Co Ltd
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Filing: 2000-07-20
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Granted: 2001-10-30
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Expires: 2020-07-20
Abstract
Abstract A secondary battery cell protection circuit includes an overcharge detection circuit detecting overcharge of a secondary battery cell, an overcharge prevention MOS transistor including a body-diode which is deactivated by a signal supplied from the overcharge detection circuit when the secondary battery cell is overcharged so as to suspend charging of the secondary battery cell, a discharge detection circuit detecting discharge of the secondary battery cell by comparing a voltage drop through the body-diode of the overcharge prevention MOS transistor with a first standard voltage, and a circuit that activates the overcharge prevention MOS transistor when the discharge detection circuit detects the discharge of the secondary battery cell.
Inventors
- 👤 Hiroshi Nagaoka
- 👤 Yukihiro Terada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 09:10
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/60; H02J7/663; H02J7/61; H02J7/63
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
97 words
A secondary battery cell protection circuit, comprising: an overcharge detection circuit detecting overcharge of a secondary battery cell; an overcharge prevention MOS transistor which is deactivated by a signal supplied from said overcharge detection circuit when the secondary battery cell is overcharged so as to suspend charging of the secondary battery cell, said overcharge prevention MOS transistor including a body-diode; a discharge detection circuit detecting discharge of the secondary battery cell through said body-diode; and a circuit that activates the overcharge prevention MOS transistor when said discharge detection circuit detects the discharge of the secondary battery cell.
Claim 2
Dependent Claim
97 words
A secondary battery cell protection circuit, comprising: an overcharge detection circuit detecting overcharge of a secondary battery cell; an overcharge prevention MOS transistor which is deactivated by a signal supplied from said overcharge detection circuit when the secondary battery cell is overcharged so as to suspend charging of the secondary battery cell, said overcharge prevention MOS transistor including a body-diode; a discharge detection circuit detecting discharge of the secondary battery cell through said body-diode; and a circuit that activates the overcharge prevention MOS transistor when said discharge detection circuit detects the discharge of the secondary battery cell.
Claim 3
Dependent Claim
31 words
The secondary battery cell protection circuit as claimed in claim 1 , wherein the overcharge detection circuit compares a charge voltage of the secondary battery cell with a first standard voltage.
Claim 4
Dependent Claim
41 words
The secondary battery cell protection circuit as claimed in claim 1 , wherein said discharge detection circuit detects said discharge of the secondary battery cell by comparing a voltage drop through said overcharge prevention MOS transistor with a second standard voltage.
Claim 5
Dependent Claim
96 words
An integrated circuit for use with an overcharge prevention MOS transistor which includes a body-diode and is deactivated when a secondary battery cell is overcharged so as to suspend charging of the secondary battery cell, said integrated circuit comprising; an overcharge detection circuit detecting overcharge of the secondary battery cell so as to deactivate the overcharge prevention MOS transistor; a discharge detection circuit detecting discharge of the secondary battery cell through said body-diode; and a circuit that activates the overcharge prevention MOS transistor when said discharge detection circuit detects the discharge of the secondary battery cell.
Claim 6
Dependent Claim
96 words
An integrated circuit for use with an overcharge prevention MOS transistor which includes a body-diode and is deactivated when a secondary battery cell is overcharged so as to suspend charging of the secondary battery cell, said integrated circuit comprising; an overcharge detection circuit detecting overcharge of the secondary battery cell so as to deactivate the overcharge prevention MOS transistor; a discharge detection circuit detecting discharge of the secondary battery cell through said body-diode; and a circuit that activates the overcharge prevention MOS transistor when said discharge detection circuit detects the discharge of the secondary battery cell.
Claim 7
Dependent Claim
28 words
The integrated circuit as claimed in claim 4 , wherein the overcharge detection circuit compares a charge voltage of the secondary battery cell with a first standard voltage.
Claim 8
Dependent Claim
38 words
The integrated circuit as claimed in claim 4 , wherein said discharge detection circuit detects said discharge of the secondary battery cell by comparing a voltage drop through said overcharge prevention MOS transistor with a second standard voltage.
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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) | 2004-10-29 | 2005-04-30 | 2005-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-29 | 2009-04-30 | 2009-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-29 | 2013-04-30 | 2013-10-30 | $7700.00 | Window Closed / Lapsed |