US3714543A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Constant current circuit constituted on a monolithic ic
Assignee: Minolta Co Ltd
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Filing: 1971-11-22
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Granted: 1973-01-30
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Expires: 1991-11-22
Abstract
Abstract A constant current transistor circuit employs a pair of PNP transistors disposed adjacent to each other on a single monolithic integrated circuit. Also included are a pair of NPN transistors disposed adjacent to each other on the same monolithic integrated circuit, with respective ones of the PNP transistors and the NPN transistors being connected to each other to form first and second combined transistor circuits. In each of the combined transistor circuits, the emitter of the PNP transistor is connected to the collector of the NPN transistor, while the collector of the PNP transistor is connected to the base of the NPN transistor, the respective bases of each PNP transistor also being connected directly to each other. Also provided is a third NPN transistor to provide constant current, the collector of which is connected to the emitter of the NPN transistor of one of the combined transistor circuits, while a diode is connected between the connected bases of the PNP transistors of the two combined transistor circuits and the collector of the third NPN transistor, while a DC power source is connected in series with a load and is provided across the third NPN transistor and said combined transistor circuits.
Inventors
- 👤 M Sahara
- 👤 Y Nanba
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:51
CPC Classifications
G; G05; G05F; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/22; G05F3/222; G05F3/225; G05F3/26; G05F3/265; B; B06; B06B; B06B2201/00; B06B2201/50; B06B2201/55
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
211 words
A constant-current circuit constituted on a monolithic integrated circuit comprising: a pair of PNP transistors which are constituted adjacent to each other on one monolithic integrated circuit, a pair of NPN transistors which are also constituted adjacent to each other on said monolithic integrated circuit, one of said PNP transistors and one of said NPN transistors being connected to form a first combined transistor circuit, the other one of said PNP transistors and the other one of said NPN transistors being connected to form a second combined transistor circuit, in each combined transistor circuit a collector and an emitter of the PNP transistor being connected to a base and a collector of the NPN transistor, respectively, the base of the PNP transistors being connected to each other; a third NPN transistor for providing a constant current, the collector of which is connected to the emitter of the NPN transistor of the second combined transistor circuit; semiconductor means connected to permit currents of the bases of the PNP transistors to flow therethrough; and a DC power source for feeding DC current to said first combined transistor circuit connected in series with a load and for feeding DC current to said second combined transistor circuit connected in series with said third NPN transistor.
Claim 2
Dependent Claim
211 words
A constant-current circuit constituted on a monolithic integrated circuit comprising: a pair of PNP transistors which are constituted adjacent to each other on one monolithic integrated circuit, a pair of NPN transistors which are also constituted adjacent to each other on said monolithic integrated circuit, one of said PNP transistors and one of said NPN transistors being connected to form a first combined transistor circuit, the other one of said PNP transistors and the other one of said NPN transistors being connected to form a second combined transistor circuit, in each combined transistor circuit a collector and an emitter of the PNP transistor being connected to a base and a collector of the NPN transistor, respectively, the base of the PNP transistors being connected to each other; a third NPN transistor for providing a constant current, the collector of which is connected to the emitter of the NPN transistor of the second combined transistor circuit; semiconductor means connected to permit currents of the bases of the PNP transistors to flow therethrough; and a DC power source for feeding DC current to said first combined transistor circuit connected in series with a load and for feeding DC current to said second combined transistor circuit connected in series with said third NPN transistor.
Claim 3
Dependent Claim
211 words
A constant-current circuit constituted on a monolithic integrated circuit comprising: a pair of PNP transistors which are constituted adjacent to each other on one monolithic integrated circuit, a pair of NPN transistors which are also constituted adjacent to each other on said monolithic integrated circuit, one of said PNP transistors and one of said NPN transistors being connected to form a first combined transistor circuit, the other one of said PNP transistors and the other one of said NPN transistors being connected to form a second combined transistor circuit, in each combined transistor circuit a collector and an emitter of the PNP transistor being connected to a base and a collector of the NPN transistor, respectively, the base of the PNP transistors being connected to each other; a third NPN transistor for providing a constant current, the collector of which is connected to the emitter of the NPN transistor of the second combined transistor circuit; semiconductor means connected to permit currents of the bases of the PNP transistors to flow therethrough; and a DC power source for feeding DC current to said first combined transistor circuit connected in series with a load and for feeding DC current to said second combined transistor circuit connected in series with said third NPN transistor.
Claim 4
Dependent Claim
211 words
A constant-current circuit constituted on a monolithic integrated circuit comprising: a pair of PNP transistors which are constituted adjacent to each other on one monolithic integrated circuit, a pair of NPN transistors which are also constituted adjacent to each other on said monolithic integrated circuit, one of said PNP transistors and one of said NPN transistors being connected to form a first combined transistor circuit, the other one of said PNP transistors and the other one of said NPN transistors being connected to form a second combined transistor circuit, in each combined transistor circuit a collector and an emitter of the PNP transistor being connected to a base and a collector of the NPN transistor, respectively, the base of the PNP transistors being connected to each other; a third NPN transistor for providing a constant current, the collector of which is connected to the emitter of the NPN transistor of the second combined transistor circuit; semiconductor means connected to permit currents of the bases of the PNP transistors to flow therethrough; and a DC power source for feeding DC current to said first combined transistor circuit connected in series with a load and for feeding DC current to said second combined transistor circuit connected in series with said third NPN transistor.
Claim 5
Dependent Claim
29 words
A constant-current circuit according to claim 1, wherein said semiconductor means is a diode connected between said bases of PNP transistors and the collector of the third NPN transistor.
Claim 6
Dependent Claim
68 words
A constant-current circuit according to claim 1, wherein said semiconductor means is a third PNP transistor, the emitter of which is connected to said bases of the first and the second PNP transistors, the base of which is connected to the collector of the third NPN transistor and the collector of which is connected to the emitter of the first NPN transistor of the first combined transistor circuit.
Claim 7
Dependent Claim
61 words
A constant-current circuit according to claim 1, wherein said semiconductor means is a circuit including a fourth and a fifth NPN transistor connected in tandem across said power source and at least one diode connected between the bases of the PNP transistors and a tandem connection point between the emitter of the fourth transistor and the collector of the fifth transistor.
Claim 8
Dependent Claim
21 words
A constant-current circuit according to claim 1, wherein all of the component semiconductor elements are constituted on one monolithic integrated circuit.
Claim 9
Dependent Claim
21 words
A constant-current circuit according to claim 2, wherein all of the component semiconductor elements are constituted on one monolithic integrated circuit.
Claim 10
Dependent Claim
21 words
A constant-current circuit according to claim 3, wherein all of the component semiconductor elements are constituted on one monolithic integrated circuit.
Claim 11
Dependent Claim
20 words
A constant-current circuit according to claim 4, wherein all the component semiconductor elements are constituted on one monolithic integrated circuit.
Claim 12
Dependent Claim
155 words
A constant-current circuit comprising: a pair of PNP transistors disposed adjacent to one another on a single monolithic integrated circuit; a pair of NPN transistors disposed adjacent to each other on said monolithic integrated circuit, one of the PNP transistors and one of the NPN transistors of each of said pairs being connected to form first and second combined transistor circuits, each combined transistor circuit having the collector and the emitter of the PNP transistor connected to the base and collector of the NPN transistor, respectively, while the bases of the PNP transistors are connected to each other; a constant-current source comprising an additional NPN transistor the collector of which is connected to the emitter of the NPN transistor of one of said combined transistor circuits; and a semiconductor switching means connected between the bases of said PNP transistors of said first and second combined transistor circuits and one electrode of said additional NPN transistor.
Claim 13
Dependent Claim
155 words
A constant-current circuit comprising: a pair of PNP transistors disposed adjacent to one another on a single monolithic integrated circuit; a pair of NPN transistors disposed adjacent to each other on said monolithic integrated circuit, one of the PNP transistors and one of the NPN transistors of each of said pairs being connected to form first and second combined transistor circuits, each combined transistor circuit having the collector and the emitter of the PNP transistor connected to the base and collector of the NPN transistor, respectively, while the bases of the PNP transistors are connected to each other; a constant-current source comprising an additional NPN transistor the collector of which is connected to the emitter of the NPN transistor of one of said combined transistor circuits; and a semiconductor switching means connected between the bases of said PNP transistors of said first and second combined transistor circuits and one electrode of said additional NPN transistor.
Claim 14
Dependent Claim
74 words
A constant-current circuit according to claim 9, wherein said semiconductor means comprises a diode, the anode of which is connected to the bases of said PNP transistors and the cathode of which is connected to the collector of said additional NPN transistor, and further including a source of DC power coupled across the emitter of said additional NPN transistor and the emitters of said PNP transistors of said first and second combined transistor circuits.
Claim 15
Dependent Claim
33 words
A constant-current circuit according to claim 10, wherein the base of said additional NPN transistor is connected to a voltage divider circuit which is connected in parallel with said source of DC power.
Claim 16
Dependent Claim
77 words
A constant-current circuit according to claim 9, wherein said semiconductor means comprises an additional PNP transistor, the emitter of which is connected to the bases of said PNP transistors of said first and second combined transistor circuits, the base of said additional PNP transistor being connected to the collector of said additional NPN transistor, and the collector of said additional PNP transistor being connected to the emitter of one of said first and second combined transistor circuits.
Claim 17
Dependent Claim
74 words
A constant-current circuit according to claim 11, wherein said semiconductor means comprises a diode, the anode of which is connected to the bases of said PNP transistors and the cathode of which is connected to the collector of said additional NPN transistor, and further including a source of DC power coupled across the emitter of said additional NPN transistor and the emitters of sAid PNP transistors of said first and second combined transistor circuits.
Claim 18
Dependent Claim
128 words
A constant-current circuit according to claim 9, wherein said semiconductor means comprises first and second series connected NPN transistors, coupled across the connection between the emitters of said PNP transistors of said first and second combined transistor circuits, and the emitter of said additional NPN transistor, the base of one of said series connected NPN transistors being connected to the base of said additional NPN transistor, while the base of the other of said series connected NPN transistors is connected to the base of the NPN transistor of one of said first and second combined circuits, and further including a diode means connected between the common connection of said series connected NPN transistors and the bases of said PNP transistors of said first and second combined transistor circuits.
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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |