US4461992A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature-compensated current source circuit and a reference voltage generating circuit using the same
Assignee: Hitachi Ltd
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Filing: 1982-04-12
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Granted: 1984-07-24
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Expires: 2002-04-12
Abstract
Abstract A current source circuit includes a first and a second transistor connected at the collector to a common load resistor. In the current source circuit, the emiiters of the first and second transistors are connected to a negative power source through different current restricting resistors. The base of the first transistor is biased by a series circuit including two diodes. The temperature coefficients of the collector currents of the first and second transistors are offset, so that the temperature-compensated current flows into the load resistor.
Inventors
- 👤 Kunihiko Yamaguchi
- 👤 Noriyuki Homma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:45
CPC Classifications
G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565; G05F1/567; G05F3/00; G05F3/02; G05F3/08; G05F3/10; G05F3/16; G05F3/20; G05F3/30; Y; Y10; Y10S; Y10S323/00; Y10S323/907
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
193 words
A current source circuit comprising: a first and a second common line having an external power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element, and at the emitter to said second common line respectively through a first and a second current restricting resistor; first bias means including a first base resistor connected between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of said first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; and second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor.
Claim 2
Dependent Claim
193 words
A current source circuit comprising: a first and a second common line having an external power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element, and at the emitter to said second common line respectively through a first and a second current restricting resistor; first bias means including a first base resistor connected between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of said first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; and second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor.
Claim 3
Dependent Claim
16 words
A current source circuit according to claim 1, wherein said first voltage-drop means includes a diode.
Claim 4
Dependent Claim
23 words
A current source circuit according to claim 2, wherein said diode is a transistor of which the collector and the base are connected.
Claim 5
Dependent Claim
20 words
A current source circuit according to claim 1, wherein said second voltage-drop means includes a series circuit having two diodes.
Claim 6
Dependent Claim
26 words
A current source circuit according to claim 4, wherein each of said two diodes is a transistor of which the collector and the base are connected.
Claim 7
Dependent Claim
52 words
A current source circuit according to claim 1, wherein said second voltage-drop means includes a third transistor connected at the collector to the base of said second transistor and at the emitter to said second common line, and having resistors between the emitter and the base and between the base and collector.
Claim 8
Dependent Claim
216 words
A reference voltage generating circuit comprising: a first and a second common line having an external power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element and at the emitter to said second common line respectively through a first and a second current restricting resistor; first bias means including a first base resistor connecting between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of said first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor; and a junction point between said load element and the collectors of said first and said second transistors functioning as an output terminal.
Claim 9
Dependent Claim
216 words
A reference voltage generating circuit comprising: a first and a second common line having an external power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element and at the emitter to said second common line respectively through a first and a second current restricting resistor; first bias means including a first base resistor connecting between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of said first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor; and a junction point between said load element and the collectors of said first and said second transistors functioning as an output terminal.
Claim 10
Dependent Claim
221 words
A reference voltage generating circuit comprising: a first and a second common line having a power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element and at the emitter to said second common line respectively through a first and a second respective current restricting resistor; first bias means including a first base resistor connected between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of the first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor; and an emitter follower circuit connected between said load element and a connection point between the collectors of said first and second transistors for producing a signal output.
Claim 11
Dependent Claim
221 words
A reference voltage generating circuit comprising: a first and a second common line having a power source connected therebetween; a load element connected at one end to said first common line; a first and a second transistor connected at the collector to the other end of said load element and at the emitter to said second common line respectively through a first and a second respective current restricting resistor; first bias means including a first base resistor connected between said first common line and the base of said first transistor, and first voltage-drop means connected between the base of the first transistor and said second common line, said first voltage-drop means generating a forward voltage-drop across a single PN junction caused by a current supplied through the first base resistor; second bias means including a second base resistor connected between said first common line and the base of said second transistor, and second voltage-drop means connected between the base of said second transistor and said second common line, said second voltage-drop means generating a forward voltage drop across a plurality of PN junctions caused by a current supplied through the second base resistor; and an emitter follower circuit connected between said load element and a connection point between the collectors of said first and second transistors for producing a signal output.
References Cited (Backward Citations)
US4319180A
Cited
US4335346A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-07-24 | 1988-01-23 | 1988-07-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-07-24 | 1992-01-23 | 1992-07-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-07-24 | 1996-01-23 | 1996-07-24 | $7700.00 | Window Closed / Lapsed |