US3843933A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current amplifier
Assignee: RCA Corp
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Filing: 1973-04-06
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Granted: 1974-10-22
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Expires: 1993-04-06
Abstract
Abstract A three-terminal current amplifier includes first and second transistors of a first conductivity type. Their respective collector electrodes are connected to input and output terminals of the current amplifier, respectively. Their emitter electrodes are each direct current conductively coupled to the common terminal of the current amplifier. Their base electrodes are coupled to the output circuit of a common-base transistor amplifier having its input circuit connected to the current amplifier input terminal. The common-base transistor amplifier employs a third transistor of a second conductivity type complementary to the first. The current gain of the current amplifier can be made to be independent of the individual current gains of the component transistors.
Inventors
- 👤 A Ahmed
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:14
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/30; H03F1/302; G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/26; G05F3/265
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
168 words
A current amplifier comprising: an input, an output and a common terminals; a first and a second transistors of like conductivity type, each having an emitter electrode direct current conductively coupled to said common terminal by means other than said first and said second transistors themselves for maintaining each emitter electrode at a potential referred to and dependent upon the potential at said common terminal, and each having a base and a collector electrodes; means for direct current conductively coupling said first transistor collector electrode to said input terminal; means for direct current conductively coupling said second transistor collector electrode to said output terminal; and a third transistor being of opposite conductivity from said first and said second transistors, having an emitter electrode direct current conductively coupled to said input terminal, having a collector electrode direct coupled to each of said first and said second transistor base electrodes, and having a base electrode direct coupled to said second transistor collector electrode and responsive to the signal present thereat.
Claim 2
Dependent Claim
168 words
A current amplifier comprising: an input, an output and a common terminals; a first and a second transistors of like conductivity type, each having an emitter electrode direct current conductively coupled to said common terminal by means other than said first and said second transistors themselves for maintaining each emitter electrode at a potential referred to and dependent upon the potential at said common terminal, and each having a base and a collector electrodes; means for direct current conductively coupling said first transistor collector electrode to said input terminal; means for direct current conductively coupling said second transistor collector electrode to said output terminal; and a third transistor being of opposite conductivity from said first and said second transistors, having an emitter electrode direct current conductively coupled to said input terminal, having a collector electrode direct coupled to each of said first and said second transistor base electrodes, and having a base electrode direct coupled to said second transistor collector electrode and responsive to the signal present thereat.
Claim 3
Dependent Claim
91 words
A current amplifier as claimed in claim 1 having: a fourth transistor of the same conductivity type as said third transistor having a base electrode direct coupled to said input terminal, having a collector and an emitter electrodes and a current conducting path therebetween, said collector electrodes of said second and said fourth transistors direct current conductively coupled, said fourth transistor emitter electrode directly connected to said output terminal, said current conducting path thereby providing said means for direct current conductively coupling said second transistor collector electrode to said output terminal.
Claim 4
Dependent Claim
29 words
A current amplifier as claimed in claim 2 arranged for regulating current flowing between said output and common Terminals wherein: a resistive element connects said input and output terminals.
Claim 5
Dependent Claim
39 words
A current amplifier as claimed in claim 1 a semiconductor diode connecting said first transistor collector electrode to said input terminal, thereby providing said means for direct current conductively coupling said first transistor collector electrode to said input electrode.
Claim 6
Dependent Claim
55 words
A current amplifier as claimed in claim 1 wherein: a semiconductor diode, included in said means for direct current conductively coupling said first transistor collector electrode to said input terminal and poled for forward conduction of the collector current of said first transistor, connects said first transistor collector electrode to said third transistor emitter electrode.
Claim 7
Dependent Claim
37 words
A current amplifier as claimed in claim 1 having: at least one common collector transistor amplifier for said direct coupling of said third transistor collector electrode to said base electrodes of said first and said second transistors.
Claim 8
Dependent Claim
32 words
A current amplifier as set forth in claim 1 wherein said emitter electrodes of said first and second transistors are connected to one another via a connection exhibiting negligible direct current impedance.
Claim 9
Dependent Claim
43 words
A current amplifier as set forth in claim 1 wherein said emitter electrodes of said first and second transistors are coupled to said common terminal via paths having a direct current impedance such that said emitter electrodes are maintained at the same potential.
Claim 10
Dependent Claim
112 words
In a current amplifier having input, common and output electrodes; having a first and a second transistors with emitter electrodes coupled to said common terminal, with collector electrodes coupled respectively to said input and said output terminals and with base electrodes; and having negative feedback means for coupling said input terminal to said base electrodes of said first and said second transistors to regulate the collector current of said first transistor to substantially equal current applied to said input terminal; the improvement comprising: positive feedback means connecting the collector electrode of said second transistor to its base electrode, whereby the dynamic output impedance exhibited between said output and common terminals is increased.
Claim 11
Dependent Claim
112 words
In a current amplifier having input, common and output electrodes; having a first and a second transistors with emitter electrodes coupled to said common terminal, with collector electrodes coupled respectively to said input and said output terminals and with base electrodes; and having negative feedback means for coupling said input terminal to said base electrodes of said first and said second transistors to regulate the collector current of said first transistor to substantially equal current applied to said input terminal; the improvement comprising: positive feedback means connecting the collector electrode of said second transistor to its base electrode, whereby the dynamic output impedance exhibited between said output and common terminals is increased.
Claim 12
Dependent Claim
42 words
The improvement set forth in claim 9 wherein said positive feedback means comprises: a third transistor connected as a common-emitter transistor amplifier as included in said positive feedback means and as a common-base transistor amplifier as included in said negative feedback means.
Claim 13
Dependent Claim
148 words
A current amplifier comprising, in combination: a common terminal, an input terminal, and an output terminal; first and second transistors, each having base, emitter and collector electrodes, said transistors coupled base electrode-to-base electrode, coupled emitter electrode-to-emitter electrode to said common terminal, said first transistor coupled at its collector electrode to said input terminal, and said second transistor coupled at its collector electrode to said output terminal; and means for maintaining the voltage at both collector electrodes substantially equal, said means including a third transistor of different conductivity than said first and second transistors, connected at its collector electrode to said base electrodes of said first and second transistors, connected at its emitter electrode to said input terminal and connected at its base electrode to said output terminal, and further including a diode connected in the forward direction between the collector of said first transistor and said input terminal.
Claim 14
Dependent Claim
148 words
A current amplifier comprising, in combination: a common terminal, an input terminal, and an output terminal; first and second transistors, each having base, emitter and collector electrodes, said transistors coupled base electrode-to-base electrode, coupled emitter electrode-to-emitter electrode to said common terminal, said first transistor coupled at its collector electrode to said input terminal, and said second transistor coupled at its collector electrode to said output terminal; and means for maintaining the voltage at both collector electrodes substantially equal, said means including a third transistor of different conductivity than said first and second transistors, connected at its collector electrode to said base electrodes of said first and second transistors, connected at its emitter electrode to said input terminal and connected at its base electrode to said output terminal, and further including a diode connected in the forward direction between the collector of said first transistor and said input terminal.
Claim 15
Dependent Claim
156 words
A current amplifier comprising: input, output and common terminals; first and second transistor means of like conductivity type, each having an emitter electrode direct current conductively coupled to said common terminal for maintaining each emitter electrode at a potential relative to the potential at said common terminal, and each having a base and a collector electrodeS; means for direct current conductively coupling said collector electrode of said first transistor means to said input terminal; means for direct current conductively coupling said collector electrode of said second transistor means to said output terminal; and third transistor means having an emitter electrode direct current conductively coupled to said input terminal, having a collector electrode direct coupled to said base electrodes of said first and second transistor means, and having a base electrode direct coupled to said collector electrode of said second transistor means and responsive to the signal present at said collector electrode of said second transistor means.
Claim 16
Dependent Claim
156 words
A current amplifier comprising: input, output and common terminals; first and second transistor means of like conductivity type, each having an emitter electrode direct current conductively coupled to said common terminal for maintaining each emitter electrode at a potential relative to the potential at said common terminal, and each having a base and a collector electrodeS; means for direct current conductively coupling said collector electrode of said first transistor means to said input terminal; means for direct current conductively coupling said collector electrode of said second transistor means to said output terminal; and third transistor means having an emitter electrode direct current conductively coupled to said input terminal, having a collector electrode direct coupled to said base electrodes of said first and second transistor means, and having a base electrode direct coupled to said collector electrode of said second transistor means and responsive to the signal present at said collector electrode of said second transistor means.
Claim 17
Dependent Claim
29 words
A current amplifier as set forth in claim 12 wherein said third transistor means comprises a single transistor of opposite conductivity type from said first and second transistor means.
Claim 18
Dependent Claim
112 words
A current amplifier as set forth in claim 12 wherein said third transistor means comprises one transistor of opposite conductivity type from said first and second transistor means, said one transistor being connected at its collector electrode to the base electrodes of the first and second transistor means, and at its emitter electrode to said input terminal, and another transistor of the same conductivity as said first and second transistor means, said another transistor being connected at its base electrode to the collector electrode of said second transistor means, at its emitter electrode to the base electrode of said one transistor, and at its collector electrode to a point of reference potential.
Claim 19
Dependent Claim
133 words
A current amplifier as set forth in claim 12 wherein said third transistor means comprises one transistor of the same conductivity type as said first and second transistor means and another transistor of opposite conductivity type from said first and second transistor means, each such transistor having collector, emitter and base electrodes, the collector electrode of said another transistor connected to the base electrodes of said first and second transistor means via the base-emitter junction of said one transistor, connected at its base electrode to the collector electrode of said second transistor, and connected at its emitter electrode to said input terminal, and said one transistor connected at its emitter electrode to the base electrodes of said first and second transistor means and at its collector electrode to a point of reference potential.
Claim 20
Dependent Claim
41 words
A current amplifier as set forth in claim 12 wherein said means for direct current conductively coupling said first transistor collector electrode to said input terminal comprises a semiconductor diode poled to conduct the collector current of said first transistor means.
Claim 21
Dependent Claim
21 words
A current amplifier as set forth in claim 12 wherein said first and second transistor means each comprises a Darlington pair.
References Cited (Backward Citations)
US3555402A
Cited
US3717777A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-21 | 1978-04-22 | 1978-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-21 | 1982-04-22 | 1982-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-21 | 1986-04-22 | 1986-10-22 | $7700.00 | Window Closed / Lapsed |