US3887879A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current mirror
Assignee: RCA Corp
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Filing: 1974-04-11
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Granted: 1975-06-03
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Expires: 1994-04-11
Abstract
Abstract A current mirror amplifier using a first and a second transistors with parallelled base-emitter circuits and collector electrodes connected to input and output terminals, respectively, includes a degenerative collector-to-base feedback connection with high current gain. Accordingly, input and output direct currents can be accurately proportioned without an inaccuracy caused by base current flows. The feedback connection may comprise a cascade connection of a third transistor and a fourth complementary conductivity transistor, each connected in commonemitter amplifier configuration.
Inventors
- 👤 Jonathan Samuel Radovsky
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:40
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/26; G05F3/265; H; H03; H03F; H03F3/00; H03F3/34; H03F3/343; H03F3/45; H03F3/45071; H03F3/45479
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
187 words
A current amplifier comprising: an input terminal, an output terminal and a common terminal; first and second and third transistors of a first conductivity type and a fourth transistor of a second conductivity type complementary to said first conductivity type, each transistor having base and emitter and collector electrodes, the emitter electrodes of said first and said second transistors being direct current conductively coupled to said common terminal, the collector electrodes of said first and said second transistors being direct current conductively coupled respectively to said input terminal and to said output terminal, the base electrode of said third transistor having said input terminal direct coupled thereto, the emitter electrode of said third transistor having the base electrodes of said first and said second transistors coupled thereto; the collector electrode of said third transistor being direct coupled to the base electrode of said fourth transistor, the collector electrode of said fourth transistor being direct coupled to said first transistor base electrode and to said second transistor base electrode; and means connected to the emitter electrode of sAid fourth transistor for biasing said fourth transistor for common-emitter amplification.
Claim 2
Dependent Claim
187 words
A current amplifier comprising: an input terminal, an output terminal and a common terminal; first and second and third transistors of a first conductivity type and a fourth transistor of a second conductivity type complementary to said first conductivity type, each transistor having base and emitter and collector electrodes, the emitter electrodes of said first and said second transistors being direct current conductively coupled to said common terminal, the collector electrodes of said first and said second transistors being direct current conductively coupled respectively to said input terminal and to said output terminal, the base electrode of said third transistor having said input terminal direct coupled thereto, the emitter electrode of said third transistor having the base electrodes of said first and said second transistors coupled thereto; the collector electrode of said third transistor being direct coupled to the base electrode of said fourth transistor, the collector electrode of said fourth transistor being direct coupled to said first transistor base electrode and to said second transistor base electrode; and means connected to the emitter electrode of sAid fourth transistor for biasing said fourth transistor for common-emitter amplification.
Claim 3
Dependent Claim
187 words
A current amplifier comprising: an input terminal, an output terminal and a common terminal; first and second and third transistors of a first conductivity type and a fourth transistor of a second conductivity type complementary to said first conductivity type, each transistor having base and emitter and collector electrodes, the emitter electrodes of said first and said second transistors being direct current conductively coupled to said common terminal, the collector electrodes of said first and said second transistors being direct current conductively coupled respectively to said input terminal and to said output terminal, the base electrode of said third transistor having said input terminal direct coupled thereto, the emitter electrode of said third transistor having the base electrodes of said first and said second transistors coupled thereto; the collector electrode of said third transistor being direct coupled to the base electrode of said fourth transistor, the collector electrode of said fourth transistor being direct coupled to said first transistor base electrode and to said second transistor base electrode; and means connected to the emitter electrode of sAid fourth transistor for biasing said fourth transistor for commonemitter amplification.
Claim 4
Dependent Claim
187 words
A current amplifier comprising: an input terminal, an output terminal and a common terminal; first and second and third transistors of a first conductivity type and a fourth transistor of a second conductivity type complementary to said first conductivity type, each transistor having base and emitter and collector electrodes, the emitter electrodes of said first and said second transistors being direct current conductively coupled to said common terminal, the collector electrodes of said first and said second transistors being direct current conductively coupled respectively to said input terminal and to said output terminal, the base electrode of said third transistor having said input terminal direct coupled thereto, the emitter electrode of said third transistor having the base electrodes of said first and said second transistors coupled thereto; the collector electrode of said third transistor being direct coupled to the base electrode of said fourth transistor, the collector electrode of said fourth transistor being direct coupled to said first transistor base electrode and to said second transistor base electrode; and means connected to the emitter electrode of sAid fourth transistor for biasing said fourth transistor for commonemitter amplification.
Claim 5
Dependent Claim
31 words
A current amplifier as set forth in claim 1 having a capacitor connected between said third transitor collector electrode and a point of direct potential as referred to said common terminal.
Claim 6
Dependent Claim
31 words
A current amplifier as set forth in claim 1 wherein a resistive element is connected from said common terminal to said joined base electrodes of said first and said second transistors.
Claim 7
Dependent Claim
31 words
A current amplifier as set forth in claim 3 having a capacitor connected between said third transistor collector electrode and a point of direct potential as referred to said common terminal.
Claim 8
Dependent Claim
80 words
A current amplifier as set forth in claim 1 having in combination therewith: a fifth and a sixth transistors of said second conductivity type, each having a base and an emitter and a collector electrodes; and means for connecting said fifth and said sixth transistors as an emitter-coupled differential amplifier including the connection of their respective collector electrodes one to said input terminal of said current mirror ampifier and the other to said output terminal of said current mirror amplifier.
Claim 9
Dependent Claim
76 words
The combination set forth in claim 5 having in further combination therewith: a seventh and an eighth transistors of said first conductivity type, each having a base and an emitter and a collector electrodes; and means for connecting said eighth transistor in Darlington cascade after said seventh transistor including said seventh transistor base electrode being connected to said current amplifier output terminal and said eighth transistor emitter electrode being connected to said current amplifier common terminal.
References Cited (Backward Citations)
US3660773A
Cited
US3813607A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |