Patent US4656435A successfully refreshed from Google Patents.
US4656435A
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Constant biasing circuit and operational amplifier using said circuit
Assignee: International Business Machines Corp
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Filing: 1985-12-23
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Granted: 1987-04-07
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Expires: 2005-12-23
Abstract
Abstract A constant biasing circuit is made to maintain a fixed difference of potential between two circuit nodes A and B otherwise at floating potential levels. The biasing circuit is made of series connected complementary transistors disposed between the circuit nodes A and B and having their gate electrodes respectively connected to opposite voltages of, e.g., +5 volts and -5 volts.
Inventors
- 👤 Jean-Christophe Czarniak
- 👤 Rene Diot
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:58
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3001
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
87 words
A constant biasing circuit for maintaining a constant difference of potential between first and second circuit nodes each at an independently floating voltage level, said constant biasing circuit comprising an output circuit having first and second devices, said first device having a control electrode connected to said first node and said second device having a control electrode connected to said second node, and a symmetrical circuit having at least two series connected complementary transistor devices disposed between said nodes, and having gates connected to opposite polarity voltages.
Claim 2
Dependent Claim
87 words
A constant biasing circuit for maintaining a constant difference of potential between first and second circuit nodes each at an independently floating voltage level, said constant biasing circuit comprising an output circuit having first and second devices, said first device having a control electrode connected to said first node and said second device having a control electrode connected to said second node, and a symmetrical circuit having at least two series connected complementary transistor devices disposed between said nodes, and having gates connected to opposite polarity voltages.
Claim 3
Dependent Claim
20 words
A constant biasing circuit, as set forth in claim 1 wherein said complementary transistor devices are complementary field effect transistors.
Claim 4
Dependent Claim
26 words
A constant biasing circuit as set forth in claim 2 wherein said complementary field effect transistors include a p channel transistor and an n channel transistor.
Claim 5
Dependent Claim
54 words
A constant biasing circuit as set forth in claim 3 wherein said opposite polarity voltages includes a given positive voltage and a given negative voltage, said given positive voltage being connected to the gate of said n channel transistor and said given negative voltage being connected to the gate of said p channel transistor.
Claim 6
Dependent Claim
109 words
A constant biasing circuit comprising first and second p channel transistors, first and second n channel transistors, and first and second points of reference potential, said first p channel transistor and said first n channel transistor being serially connected between said first and second points of reference potential, said second p channel transistor and said second n channel transistor being serially connected between the gates of said first p channel and n channel transistors, said first point of reference potential being connected to the gate of said second n channel transistor, and said second point of reference potential being connected to the gate of said second p channel transistor.
Claim 7
Dependent Claim
109 words
A constant biasing circuit comprising first and second p channel transistors, first and second n channel transistors, and first and second points of reference potential, said first p channel transistor and said first n channel transistor being serially connected between said first and second points of reference potential, said second p channel transistor and said second n channel transistor being serially connected between the gates of said first p channel and n channel transistors, said first point of reference potential being connected to the gate of said second n channel transistor, and said second point of reference potential being connected to the gate of said second p channel transistor.
Claim 8
Dependent Claim
25 words
A constant biasing circuit as set forth in claim 5 wherein said first and second points of reference potential are positive and negative potentials, respectively.
Claim 9
Dependent Claim
30 words
A constant biasing circuit as set forth in claim 6 wherein said positive potential has a magnitude of +5 volts and said negative potential has a magnitude of -5 volts.
Claim 10
Dependent Claim
86 words
An operational amplifier having a push-pull output stage including a p channel field effect transistor and an n channel field effect transistor the gates of which are to be driven through a driving stage providing floating voltages to the respective gates of said p and n channel transistors, said operational amplifier comprising a constant biasing circuit including a symmetrical circuit having two series connected complementary transistors disposed between the gates of said p channel and n channel transistors and having gates connected to opposite polarity voltages.
Claim 11
Dependent Claim
86 words
An operational amplifier having a push-pull output stage including a p channel field effect transistor and an n channel field effect transistor the gates of which are to be driven through a driving stage providing floating voltages to the respective gates of said p and n channel transistors, said operational amplifier comprising a constant biasing circuit including a symmetrical circuit having two series connected complementary transistors disposed between the gates of said p channel and n channel transistors and having gates connected to opposite polarity voltages.
Claim 12
Dependent Claim
18 words
An operational amplifier as set forth in claim 8 wherein said complementary transistors are complementary field effect transistors.
Claim 13
Dependent Claim
27 words
An operational amplifier as set forth in claim 9 wherein said complementary field effect transistors include a second p channel transistor and a second n channel transistor.
Claim 14
Dependent Claim
55 words
An operational amplifier as set forth in claim 10 wherein said opposite polarity voltages includes a given positive voltage and a given negative voltage, said given positive voltage being connected to the gate of said second n channel transistor and said given negative voltage being connected to the gate of said second p channel transistor.
Claim 15
Dependent Claim
31 words
An operational amplifier as set forth in claim 11 wherein said given positive voltage has a magnitude of +5 volts and said given negative voltage has a magnitude of -5 volts.
References Cited (Backward Citations)
US3611170A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-04-06 | 1990-10-06 | 1991-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-04-06 | 1994-10-06 | 1995-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-04-06 | 1998-10-06 | 1999-04-07 | $7700.00 | Window Closed / Lapsed |