US5583384A
Expired / Lapsed
US
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Method and apparatus for connecting and disconnecting a power field effect transistor
Assignee: National Semiconductor Corp
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Filing: 1995-06-07
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Granted: 1996-12-10
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Expires: 2015-06-07
Abstract
Abstract A power switch includes two power FETs connected back-to-back in series at a common source node and a common gate node and a resistor connected between the common source node and the common gate node. The switch further includes a current source and a single-control switch connected to the current source and to the gate node for switching the current source to the gates of the two power FETs.
Inventors
- 👤 Paul M. Henry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:43
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/51; H03K17/56; H03K17/687; H03K17/6871; H03K17/6874; H01; H01M; H01M10/00; H01M10/42; H01M10/48; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 42
Claim 1
Independent Claim
48 words
A power switch comprising: two power FETs coupled back-to-back in series at a common source node and a common gate node; a resistor coupled between the common source node and the common gate node; and a FET coupled to the two power FETs and coupled to the resistor.
Claim 2
Dependent Claim
48 words
A power switch comprising: two power FETs coupled back-to-back in series at a common source node and a common gate node; a resistor coupled between the common source node and the common gate node; and a FET coupled to the two power FETs and coupled to the resistor.
Claim 3
Dependent Claim
96 words
A switch according to claim 1 wherein the two power FETs include: a first N-channel MOSFET having a source terminal coupled to a first end of the resistor, a drain terminal and a gate terminal coupled to the second end of the resistor; and a second N-channel MOSFET having a source terminal coupled to the source terminal of the first N-channel MOSFET and coupled to the first end of the resistor, a drain terminal and a gate terminal coupled to the gate terminal of the first N-channel MOSFET and to the second end of the resistor.
Claim 4
Dependent Claim
43 words
A switch according to claim 2 further comprising: a high voltage P-channel MOSFET having a source terminal and having a drain terminal coupled to the gate terminals of the first and second N-channel MOSFETs and coupled to the second end of the resistor.
Claim 5
Dependent Claim
27 words
A switch according to claim 3 further comprising: a current source; a switch coupling the current source to the source terminal of the high voltage P-channel MOSFET.
Claim 6
Dependent Claim
33 words
A switch according to claim 1 further comprising: two diodes respectively coupled across the source/drain pathways of the two power FETs, the diodes being conductive from source to drain of respective power FETs.
Claim 7
Dependent Claim
12 words
A switch according to claim 5 wherein the diodes are body-drain diodes.
Claim 8
Dependent Claim
29 words
A switch according to claim 1 further comprising: a battery coupled in series with the two power FETs, the power FETs being used to connect and disconnect the battery.
Claim 9
Dependent Claim
55 words
A switch according to claim 7 further comprising: a first terminal at a first end of the series-connected battery and power FETs; and a second terminal at a second end of the series-connected battery and power FETs, the first and second terminals for connecting a positive terminal and a negative terminal of a battery charger.
Claim 10
Dependent Claim
38 words
A switch according to claim 1 further comprising: a current source; and a control switch coupled to the current source and to the gate node for switching the current source to the gates of the two power FETs.
Claim 11
Dependent Claim
25 words
A switch according to claim 1 wherein the resistor is a relatively large resistor having a resistance in a range from approximately 100KΩ to 20MΩ.
Claim 12
Dependent Claim
53 words
A battery pack comprising: two power FETs coupled back-to-back in series at a common source node and a common gate node; a resistor coupled between the common source node and the common gate node; and a controller having a control terminal coupled to the common gate node to control the two power FETs.
Claim 13
Dependent Claim
53 words
A battery pack comprising: two power FETs coupled back-to-back in series at a common source node and a common gate node; a resistor coupled between the common source node and the common gate node; and a controller having a control terminal coupled to the common gate node to control the two power FETs.
Claim 14
Dependent Claim
38 words
A battery pack according to claim 11 wherein the controller further comprises: a transistor coupled to the two power FETs at the common gate node; an electrical source; and a switch coupling the electrical source to the transistor.
Claim 15
Dependent Claim
38 words
A battery pack according to claim 11 wherein the controller further comprises: a FET coupled to the two power FETs at the common gate node; a current source; and a switch coupling the current source to the FET.
Claim 16
Dependent Claim
97 words
A battery pack according to claim 11 wherein the two power FETs include: a first N-channel MOSFET having a source terminal coupled to a first end of the resistor, a drain terminal and a gate terminal coupled to the second end of the resistor; and a second N-channel MOSFET having a source terminal coupled to the source terminal of the first N-channel MOSFET and coupled to the first end of the resistor, a drain terminal and a gate terminal coupled to the gate terminal of the first N-channel MOSFET and to the second end of the resistor.
Claim 17
Dependent Claim
82 words
A battery pack according to claim 14 wherein the controller further comprises: a high voltage FET coupled to the two power FETs at the common gate node, the high voltage FET including: a high voltage P-channel MOSFET having a source terminal and having a drain terminal coupled to the gate terminals of the first and second N-channel MOSFETs and coupled to the second end of the resistor; a current source; and a switch coupling the current source to the high voltage FET.
Claim 18
Dependent Claim
34 words
A battery pack according to claim 11 further comprising: two diodes respectively coupled across the source/drain pathways of the two power FETs, the diodes being conductive from source to drain of respective power FETs.
Claim 19
Dependent Claim
13 words
A battery pack according to claim 16 wherein the diodes are body-drain diodes.
Claim 20
Dependent Claim
30 words
A battery pack according to claim 11 further comprising: a battery coupled in series with the two power FETs, the power FETs being used to connect and disconnect the battery.
Claim 21
Dependent Claim
56 words
A battery pack according to claim 18 further comprising: a first terminal at a first end of the coupled battery and power FETs; and a second terminal at a second end of the series-connected battery and power FETs, the first and second terminals for connecting a positive terminal and a negative terminal of a battery charger.
Claim 22
Dependent Claim
42 words
A battery pack according to claim 11 wherein the controller further comprises: a current source; and a control switch coupled to the current source and to the gate node for switching the current source to the gates of the two power FETs.
Claim 23
Dependent Claim
26 words
A battery pack according to claim 11 wherein the resistor is a relatively large resistor having a resistance in a range from approximately 0.1MΩ to 20MΩ.
Claim 24
Independent Claim
67 words
A method of connecting and disconnecting a battery from a circuit comprising the steps of: coupling two power FETs back-to-back in series at a common source node and a common gate node; coupling a resistor between the common source node and the common gate node; and coupling a battery in series with the two power FETs, the power FETs being used to connect and disconnect the battery.
Claim 25
Independent Claim
67 words
A method of connecting and disconnecting a battery from a circuit comprising the steps of: coupling two power FETs back-to-back in series at a common source node and a common gate node; coupling a resistor between the common source node and the common gate node; and coupling a battery in series with the two power FETs, the power FETs being used to connect and disconnect the battery.
Claim 26
Dependent Claim
35 words
A method according to claim 22, further comprising the step of: sourcing a current through the resistor so that a first power FET and a second power FET of the two power FETs are conductive.
Claim 27
Dependent Claim
35 words
A method according to claim 23, further comprising the step of: removing the current through the resistor so that the first power FET and the second power FET of the two power FETs are nonconductive.
Claim 28
Dependent Claim
24 words
A method according to claim 22, further comprising the step of: connecting a battery charger in parallel with the series-connected battery and power FETs.
Claim 29
Dependent Claim
35 words
A method according to claim 25, further comprising the step of: sourcing a current through the resistor so that a first power FET and a second power FET of the two power FETs are conductive.
Claim 30
Dependent Claim
35 words
A method according to claim 26, further comprising the step of: removing the current through the resistor so that the first power FET and the second power FET of the two power FETs are nonconductive.
Claim 31
Dependent Claim
83 words
A power switch comprising: two power FETs coupled back-to-back in series including a first power FET having a source terminal and a gate terminal and a second power FET having a source terminal directly coupled to the source terminal of the first power FET at a common source node and a gate terminal directly coupled to the gate terminal of the first power FET at a common gate node; and a resistor coupled between the common source node and the common gate node.
Claim 32
Dependent Claim
83 words
A power switch comprising: two power FETs coupled back-to-back in series including a first power FET having a source terminal and a gate terminal and a second power FET having a source terminal directly coupled to the source terminal of the first power FET at a common source node and a gate terminal directly coupled to the gate terminal of the first power FET at a common gate node; and a resistor coupled between the common source node and the common gate node.
Claim 33
Dependent Claim
21 words
A switch according to claim 28 further comprising: a FET coupled to the two power FETs and coupled to the resistor.
Claim 34
Dependent Claim
96 words
A switch according to claim 28 wherein the two power FETs include: a first N-channel MOSFET having a source terminal coupled to a first end of the resistor, a drain terminal and a gate terminal coupled to the second end of the resistor; and a second N-channel MOSFET having a source terminal coupled to the source terminal of the first N-channel MOSFET and coupled to the first end of the resistor, a drain terminal and a gate terminal coupled to the gate terminal of the first N-channel MOSFET and to the second end of the resistor.
Claim 35
Dependent Claim
43 words
A switch according to claim 30 further comprising: a high voltage P-channel MOSFET having a source terminal and having a drain terminal coupled to the gate terminals of the first and second N-channel MOSFETs and coupled to the second end of the resistor.
Claim 36
Dependent Claim
27 words
A switch according to claim 3 further comprising: a current source; a switch coupling the current source to the source terminal of the high voltage P-channel MOSFET.
Claim 37
Dependent Claim
33 words
A switch according to claim 28 further comprising: two diodes respectively coupled across the source/drain pathways of the two power FETs, the diodes being conductive from source to drain of respective power FETs.
Claim 38
Dependent Claim
12 words
A switch according to claim 33 wherein the diodes are body-drain diodes.
Claim 39
Dependent Claim
29 words
A switch according to claim 28 further comprising: a battery coupled in series with the two power FETs, the power FETs being used to connect and disconnect the battery.
Claim 40
Dependent Claim
55 words
A switch according to claim 35 further comprising: a first terminal at a first end of the series-connected battery and power FETs; and a second terminal at a second end of the series-connected battery and power FETs, the first and second terminals for connecting a positive terminal and a negative terminal of a battery charger.
Claim 41
Dependent Claim
38 words
A switch according to claim 28 further comprising: a current source; and a control switch coupled to the current source and to the gate node for switching the current source to the gates of the two power FETs.
Claim 42
Dependent Claim
25 words
A switch according to claim 28 wherein the resistor is a relatively large resistor having a resistance in a range from approximately 100KΩ to 20MΩ.
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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) | 1999-12-10 | 2000-06-10 | 2000-12-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-10 | 2004-06-10 | 2004-12-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-10 | 2008-06-10 | 2008-12-10 | $7700.00 | Window Closed / Lapsed |