US3872390A
Expired / Lapsed
US
⏱️ 0.0 years remaining
CMOS operational amplifier with internal emitter follower
Assignee: Motorola Solutions Inc
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Filing: 1973-12-26
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Granted: 1975-03-18
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Expires: 1993-12-26
Abstract
Abstract A bipolar transistor is provided on a CMOS semiconductor chip in combination with an emitter follower resistor, A CMOS inverter, an input resistor and a feedback resistor. The bipolar transistor and the emitter follower resistor are connected to form an emitter follower, which has its input connected to the output of the CMOS inverter. A high resistance feedback resistor is connected between the output of the emitter follower and the input of the CMOS inverter. A high value input resistor is connected between the input conductor of the operational amplifier and the input of the CMOS inverter.
Inventors
- 👤 Harold Garth Nash
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:29
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/34; H03F3/343; H03F3/345
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
148 words
An integrated circuit operational amplifier comprising: a non-switching CMOS gain circuit; an output circuit including a bipolar transistor having its base connected to an output of said CMOS gain circuit and having its emitter connected to an output of said integrated circuit operational amplifier for providing low output impedance; and, bias means coupled to said output of said integrated circuit operational amplifier and to an input of said non-switching CMOS gain circuit for biasing said non-switching CMOS gain circuit to provide gain for said integrated circuit operational amplifier proportional to a ratio of resistors of said bias circuit means, said bias circuit means including a first resistor connected between an inpUt of said integrated circuit operational amplifier and said input of said non-switching CMOS gain circuit and a feedback resistor connected between said output of said integrated operational amplifier and said input of said non-switching CMOS gain circuit.
Claim 2
Dependent Claim
148 words
An integrated circuit operational amplifier comprising: a non-switching CMOS gain circuit; an output circuit including a bipolar transistor having its base connected to an output of said CMOS gain circuit and having its emitter connected to an output of said integrated circuit operational amplifier for providing low output impedance; and, bias means coupled to said output of said integrated circuit operational amplifier and to an input of said non-switching CMOS gain circuit for biasing said non-switching CMOS gain circuit to provide gain for said integrated circuit operational amplifier proportional to a ratio of resistors of said bias circuit means, said bias circuit means including a first resistor connected between an inpUt of said integrated circuit operational amplifier and said input of said non-switching CMOS gain circuit and a feedback resistor connected between said output of said integrated operational amplifier and said input of said non-switching CMOS gain circuit.
Claim 3
Dependent Claim
189 words
A CMOS integrated circuit operational amplifier on a semiconductor chip comprising; non-switching CMOS amplifier means including a first MOSFET of a first cnductivity type and a second MOSFET of a second conductivity type, said first MOSFET having its source coupled to a first voltage conductor, a gate coupled to a gate of said second MOSFET, and a drain coupled to a drain of said second MOSFET, said second MOSFET having a source coupled to a second voltage conductor; an emitter follower including a bipolar transistor having a collector coupled to said first voltage conductor, a base coupled to said drains of said first and second MOSFETS an emitter coupled to emitter current source means; and, bias circuit means including an input resistor coupled between an input of said CMOS integrated circuit operational amplifier and said gates of said first and second MOSFETs and a feedback resistor connected between said emitter and said gates of said first and second MOSFET''s for biasing said non-switching amplifier means at a bias point establishing the gain of said operational amplifier substantially equal to the ratio between said input resistor and said feedback resistor.
Claim 4
Dependent Claim
189 words
A CMOS integrated circuit operational amplifier on a semiconductor chip comprising; non-switching CMOS amplifier means including a first MOSFET of a first cnductivity type and a second MOSFET of a second conductivity type, said first MOSFET having its source coupled to a first voltage conductor, a gate coupled to a gate of said second MOSFET, and a drain coupled to a drain of said second MOSFET, said second MOSFET having a source coupled to a second voltage conductor; an emitter follower including a bipolar transistor having a collector coupled to said first voltage conductor, a base coupled to said drains of said first and second MOSFETS an emitter coupled to emitter current source means; and, bias circuit means including an input resistor coupled between an input of said CMOS integrated circuit operational amplifier and said gates of said first and second MOSFETs and a feedback resistor connected between said emitter and said gates of said first and second MOSFET''s for biasing said non-switching amplifier means at a bias point establishing the gain of said operational amplifier substantially equal to the ratio between said input resistor and said feedback resistor.
Claim 5
Dependent Claim
36 words
The CMOS operational amplifier as recited in claim 2 wherein said first MOSFET is P-channel and said second MOSFET is N-channel, and said bipolar transistor is a vertical NPN transistor formed in a tub type region.
Claim 6
Dependent Claim
17 words
The CMOS operational amplifier as recited in claim 2 wherein said emitter current source is a resistor.
Claim 7
Dependent Claim
22 words
The CMOS operational amplifier as recited in claim 2 wherein said feedback resistor is a resistor formed from a tub type region.
Claim 8
Dependent Claim
20 words
A CMOS operational amplifier as recited in claim 2 wherein said feedback resistor is a MOSFET biased as a resistor.
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) | 1978-03-17 | 1978-09-16 | 1979-03-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-17 | 1982-09-16 | 1983-03-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-17 | 1986-09-16 | 1987-03-18 | $7700.00 | Window Closed / Lapsed |