US3813607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Current amplifier
Assignee: US Philips Corp
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Filing: 1972-10-18
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Granted: 1974-05-28
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Expires: 1992-10-18
Abstract
Abstract Circuit arrangement providing a constant current amplification which is determined by the ratio between the emitter surface areas of a first and a second transistor of one conductivity type, the first transistor passing the input current and the second transistor passing the output current. The base currents for these transistors are supplied by a third transistor of the other conductivity type the base of which is connected to the collector of a fourth transistor of the one conductivity type in common emitter connection the base of which is connected to the input. This method of driving ensures a high degree of accuracy and also permits the use of a small supply voltage. The circuit may be used to particular advantage in a current stabilizer.
Inventors
- 👤 J Voorman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 09:48
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/34; H03F3/343; H03F3/347; G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/26; G05F3/265
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
153 words
A current amplifier comprising: an input terminal; a first transistor of one conductivity type, having a collector connected to said input terminal and having a base and an emitter; an output terminal; a second transistor of said one conductivity type, having a collectoR connected to said output terminal, having a base connected to said first transistor base, and having an emitter connected to said first transistor emitter; a third transistor of conductivity type opposite to said first conductivity type, having a collector connected to said connected bases of said first and second transistors, and having a base and an emitter; a fourth transistor of said one conductivity type, having a collector connected to said third transistor base, having a base connected to said input terminal, and having an emitter connected to said first transistor emitter; and means for connecting a supply voltage source between said third transistor emitter and said first transistor emitter.
Claim 2
Dependent Claim
153 words
A current amplifier comprising: an input terminal; a first transistor of one conductivity type, having a collector connected to said input terminal and having a base and an emitter; an output terminal; a second transistor of said one conductivity type, having a collectoR connected to said output terminal, having a base connected to said first transistor base, and having an emitter connected to said first transistor emitter; a third transistor of conductivity type opposite to said first conductivity type, having a collector connected to said connected bases of said first and second transistors, and having a base and an emitter; a fourth transistor of said one conductivity type, having a collector connected to said third transistor base, having a base connected to said input terminal, and having an emitter connected to said first transistor emitter; and means for connecting a supply voltage source between said third transistor emitter and said first transistor emitter.
Claim 3
Dependent Claim
33 words
A current amplifier as defined in claim 1 and further comprising means for increasing the bias currents in said third and fourth transistors to thereby improve the frequency response of said current amplifier.
Claim 4
Dependent Claim
47 words
A current amplifier as defined in claim 2 wherein said means for increasing the bias current of said third transistor comprises a diode of said one conductivity type having a collector connected to said first transistor base, and having an emitter connected to said first transistor emitter.
Claim 5
Dependent Claim
47 words
A current amplifier as defined in claim 2 wherein said means for increasing the bias current of said fourth transistor comprises a diode of said opposite conductivity type having a collector connected to said third transistor base, and having an emitter connected to said third transistor emitter.
Claim 6
Dependent Claim
35 words
A current amplifier as defined in claim 2 wherein said means for increasing the bias current of said fourth transistor comprises a current source connected between said fourth transistor collector and said third transistor emitter.
Claim 7
Dependent Claim
28 words
A current amplifier as defined in claim 1 wherein said first, second and fourth transistors are lateral pnp transistors and said third transistor is a vertical npn transistor.
Claim 8
Dependent Claim
125 words
A current stabilizer comprising a current amplifier as defined in claim 1 wherein said second transistor has a larger emitter area than said first transistor and said second transistor emitter is connected to said first transistor emitter through a resistance to thereby establish an emitter current ratio therebetween, and further comprising: a fifth transistor of said opposite conductivity type, having a collector and a base connected to said output terminal, and having an emitter connected to said third transistor emitter; a sixth transistor of said opposite conductivity type, having a collector connected to said input terminal, having an emitter connected to said third transistor emitter, and having a base connected to said fifth transistor base; and output means electrically connected to said first transistor base.
Claim 9
Dependent Claim
33 words
A current stabilizer as defined in claim 6 and further comprising means for increasing the bias currents in said third and fourth transistors to thereby improve the frequency response of said current stabilizer.
Claim 10
Dependent Claim
30 words
A current stabilizer as defined in claim 8 wherein said first, second and fourth transistors are lateral pnp transistors and said third, fifth and sixth transistors are vertical npn transistors.
References Cited (Backward Citations)
US3614645A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |