Patent US5412263A successfully refreshed from Google Patents.
US5412263A
Expired / Lapsed
US
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Multiple control voltage generation for MOSFET resistors
Assignee: AT&T Inc
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Filing: 1992-09-30
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Granted: 1995-05-02
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Expires: 2012-09-30
Abstract
Abstract Control voltages are generated so that each transistor in a plurality of parallel connected field effect transistors turns ON with smooth transitions between transistors and in a manner that is relatively insensitive to processing and operating temperature variations.
Inventors
- 👤 Krishnaswamy Nagaraj
- 👤 Reza S. Shariatdoust
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:29
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/13; H03K5/133; H03K5/134; H03H; H03H11/00; H03H11/02; H03H11/24; H03H11/245
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
126 words
A variable resistor comprising: a plurality of first parallel connected field effect transistors, each having a gate electrode, the resistance of said resistor being the source/drain resistances of said transistors; means for generating analog control voltages for each of said first field effect transistors, said means comprising a plurality of second field effect transistors, current carrying elments connected between source electrodes of said second field effect transistors and a reference potential, said source electrodes of transistors of said second plurality being connected to said gate electrodes of transistors of said first plurality; a current transfer circuit, at least one of said second transistors having a source electrode connected to said current transfer circuit; and means for generating a reference voltage connected to said current transfer circuit.
Claim 2
Dependent Claim
126 words
A variable resistor comprising: a plurality of first parallel connected field effect transistors, each having a gate electrode, the resistance of said resistor being the source/drain resistances of said transistors; means for generating analog control voltages for each of said first field effect transistors, said means comprising a plurality of second field effect transistors, current carrying elments connected between source electrodes of said second field effect transistors and a reference potential, said source electrodes of transistors of said second plurality being connected to said gate electrodes of transistors of said first plurality; a current transfer circuit, at least one of said second transistors having a source electrode connected to said current transfer circuit; and means for generating a reference voltage connected to said current transfer circuit.
Claim 3
Dependent Claim
17 words
A variable resistor as recited in claim 1 in which said current carrying element comprises a resistance.
Claim 4
Dependent Claim
29 words
A variable resistor as recited in claim 2 in which said means for generating provides a smooth turn-on transition for said plurality of first parallel connected field effect transistor.
Claim 5
Dependent Claim
126 words
An integrated circuit comprising: a plurality of first parallel connected field effect transistors, each having a gate electrode, the resistance of said resistor being the source/drain resistances of said transistors; means for generating analog control voltages for each of said first field effect transistors, said means comprising a plurality of second field effect transistors, current carrying elements connected between a source electrodes of said second field effect transistors, and a reference potential, said source electrodes of transistors of said second plurality being connected to said gate electrodes of transistors of said first plurality; a current transfer circuit, at least one of said transistors having a source electrode connected to said current transfer circuit; and means for generating a reference voltage connected to said current transfer circuit.
Claim 6
Dependent Claim
126 words
An integrated circuit comprising: a plurality of first parallel connected field effect transistors, each having a gate electrode, the resistance of said resistor being the source/drain resistances of said transistors; means for generating analog control voltages for each of said first field effect transistors, said means comprising a plurality of second field effect transistors, current carrying elements connected between a source electrodes of said second field effect transistors, and a reference potential, said source electrodes of transistors of said second plurality being connected to said gate electrodes of transistors of said first plurality; a current transfer circuit, at least one of said transistors having a source electrode connected to said current transfer circuit; and means for generating a reference voltage connected to said current transfer circuit.
Claim 7
Dependent Claim
17 words
An integrated circuit as recited in claim 4 in which said current carrying element comprises a resistance.
Claim 8
Dependent Claim
29 words
An integrated circuit as recited in claim 4 in which said means for generating provides a smooth turn-on transistion for said plurality of first parallel connected field effect transistors.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-05-01 | 1998-10-31 | 1999-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-01 | 2002-10-31 | 2003-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-01 | 2006-10-31 | 2007-05-02 | $7700.00 | Window Closed / Lapsed |