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US4763018A
Expired / Lapsed
US
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Transistor constant bias circuits
Assignee: Plessey Semiconductors Ltd
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Filing: 1987-02-05
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Granted: 1988-08-09
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Expires: 2007-02-05
Abstract
Abstract A circuit (FIG. 4) in which a sub-circuit comprised of a bias transistor (T1), a feedback reisistor (R2) connected between the collector of this transistor (T1) and its base, and, a drive transistor (T2), is connected to its polarity-inverse sub-circuit (T1', R2', T2') in a ring configuration and is initiated by means of current injection from a start-up bias circuit. The latter may comprise a bias transistor (T1"), a drive transistor (T2") the base of which is connected to the collector of the bias transistor (T1"), and a pair of feedback current/voltage divider resistors (R1", R2") in the collector path of the bias transistor (T1"). Following start-up, constant current is maintained by feedback in the ring, and this current may be tapped at an appropriate point in the ring.
Inventors
- 👤 Philip A. K. Moon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:23
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/30
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
339 words
A bias-current generator circuit comprising: an NPN-type bipolar cascaded current amplifier comprised of: a first power rail; an NPN-type bipolar bias transistor, having an emitter, a base, and, a collector; a first collector path conductor connected to the collector of the NPN-type bias transistor; a first feedback conductor, connected between the first collector path conductor and the base of the NPN-type bias transistor; a first resistor, inserted in the first collector path conductor, between the collector of the NPN-type bias transistor, and, the first feedback conductor; an NPN-type bipolar drive transistor, having an emitter, a base, and a collector, the base of which NPN-type bipolar drive transistor is connected to the collector of the NPN-type bipolar bias transistor; and, wherein, the emitters of the NPN-type bipolar bias and drive transistors are connected to the first power rail; a PNP-type cascaded current amplifier comprised of: a second power rail; a PNP-type bipolar bias transistor, having an emitter, a base, and a collector; a second collector path conductor connected to the collector of the PNP-type bias transistor; a second feedback conductor, connected between the second collector path conductor and the base of the PNP-type bias transistor; a second resistor, inserted in the second collector path conductor, between the collector of the PNP-type bias transistor, and, the second feedback conductor; an PNP-type bipolar drive transistor, having an emitter, a base, and, a collector, the base of which PNP-type bipolar drive transistor is connected to the collector of the PNP-type bipolar bias transistor; and, wherein, the emitters of the PNP-type bipolar bias and drive transistors are connected to the second power rail; and, wherein, the first collector path conductor is connected to the collector of the PNP-type bipolar drive transistor, and, the second collector path conductor is connected to the collector of the NPN-type bipolar drive transistor such that the NPN-type bipolar drive transistor, the second resistor, the PNP-type drive transistor, and the first resistor are connected in a ring, and, a start-up current bias circuit connected to a point in said ring.
Claim 2
Dependent Claim
339 words
A bias-current generator circuit comprising: an NPN-type bipolar cascaded current amplifier comprised of: a first power rail; an NPN-type bipolar bias transistor, having an emitter, a base, and, a collector; a first collector path conductor connected to the collector of the NPN-type bias transistor; a first feedback conductor, connected between the first collector path conductor and the base of the NPN-type bias transistor; a first resistor, inserted in the first collector path conductor, between the collector of the NPN-type bias transistor, and, the first feedback conductor; an NPN-type bipolar drive transistor, having an emitter, a base, and a collector, the base of which NPN-type bipolar drive transistor is connected to the collector of the NPN-type bipolar bias transistor; and, wherein, the emitters of the NPN-type bipolar bias and drive transistors are connected to the first power rail; a PNP-type cascaded current amplifier comprised of: a second power rail; a PNP-type bipolar bias transistor, having an emitter, a base, and a collector; a second collector path conductor connected to the collector of the PNP-type bias transistor; a second feedback conductor, connected between the second collector path conductor and the base of the PNP-type bias transistor; a second resistor, inserted in the second collector path conductor, between the collector of the PNP-type bias transistor, and, the second feedback conductor; an PNP-type bipolar drive transistor, having an emitter, a base, and, a collector, the base of which PNP-type bipolar drive transistor is connected to the collector of the PNP-type bipolar bias transistor; and, wherein, the emitters of the PNP-type bipolar bias and drive transistors are connected to the second power rail; and, wherein, the first collector path conductor is connected to the collector of the PNP-type bipolar drive transistor, and, the second collector path conductor is connected to the collector of the NPN-type bipolar drive transistor such that the NPN-type bipolar drive transistor, the second resistor, the PNP-type drive transistor, and the first resistor are connected in a ring, and, a start-up current bias circuit connected to a point in said ring.
Claim 3
Dependent Claim
72 words
A circuit, as claimed in claim 1, wherein the start-up current bias circuit comprises: a bias transistor; a pair of resistors, in the collector path of the bias transistor, and connected to apply feedback to the base of the bias transistor; and, a drive transistor, the base of which is connected to the collector of the start-up bias transistor, the collector of which is connected to the point in the ring configuration.
Claim 4
Dependent Claim
46 words
A circuit, as claimed in claim 2, wherein the bias transistor and the drive transistor of the start-up circuit are both of NPN-type and the collector of the start-up drive transistor is connected to the ring configuration at the collector of the NPN drive transistor thereof.
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) | 1991-08-09 | 1992-02-08 | 1992-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-08-09 | 1996-02-08 | 1996-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-08-09 | 2000-02-08 | 2000-08-09 | $7700.00 | Window Closed / Lapsed |