Patent US4897611A successfully refreshed from Google Patents.
US4897611A
Expired / Lapsed
US
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Very high gain positive feedback CMOS transconductance amplifier
Assignee: Fairchild Semiconductor Corp
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Filing: 1988-10-28
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Granted: 1990-01-30
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Expires: 2008-10-28
Abstract
Abstract This invention is for a transconductance amplifier. The amplifier has an amplifier input and an amplifier output with an amplifier output impedance. An input stage of the amplifier has a first transconductance. An intermediate state is coupled to the amplifier output through positive feedback. The intermediate stage has a second transconductance and an intermediate stage output having an intermediate output impedance. The gain of the amplifier is a function of the first transconductance times the second transconductance times the amplifier output impedance times the intermediate output impedance.
Inventors
- 👤 Carlos A. Laber
- 👤 Paul R. Gray
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:07
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/45179; H03F3/45183; H03F3/45192; H03F1/00; H03F1/38; H03F3/30; H03F3/3001
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
108 words
A transconductance amplifier with a gain having an amplifier input, an amplifier output and an amplifier output impedance, said amplifier comprising: a. a first amplification means coupled to said amplifier input and having a first transconductance; and b. a second amplification means having a second amplifier input, a second transconductance and a second output with a second output impedance; and c. positive feedback means for coupling the output of said amplifier to the second amplifier input of said second amplification means, wherein the gain of the amplifier is a function of the first transconductance times the second transconductance times the amplifier output impedance times the second output impedance.
Claim 2
Dependent Claim
108 words
A transconductance amplifier with a gain having an amplifier input, an amplifier output and an amplifier output impedance, said amplifier comprising: a. a first amplification means coupled to said amplifier input and having a first transconductance; and b. a second amplification means having a second amplifier input, a second transconductance and a second output with a second output impedance; and c. positive feedback means for coupling the output of said amplifier to the second amplifier input of said second amplification means, wherein the gain of the amplifier is a function of the first transconductance times the second transconductance times the amplifier output impedance times the second output impedance.
Claim 3
Dependent Claim
17 words
The transconductance amplifier according to claim 1 wherein the amplifier is manufactured as a CMOS integrated circuit.
Claim 4
Dependent Claim
18 words
The transconductance amplifier according to claim 2 wherein the first amplification means is a differential to differential amplifier.
Claim 5
Dependent Claim
18 words
The transconductance amplifier according to claim 3 wherein the second amplification means is a differential to common-mode amplifier.
Claim 6
Dependent Claim
24 words
The transconductance amplifier according to claim 3 wherein the second amplification means output is coupled to receive a signal responsive to said amplifier input.
Claim 7
Dependent Claim
23 words
The transconductance amplifier according to claim 1 wherein the second amplifier stage has an output that is a mirror to the amplifier output.
Claim 8
Dependent Claim
92 words
A CMOS transconductance type amplifier of the type having a differential input stage having a first transconductance and an amplifier output having an amplifier output impedance wherein the improvement comprises: a. a second amplifier stage having a second input, a second transconductance and a second output with a second output impedance; and b. a positive feedback path coupling the amplifier output to the second input, whereby the gain of the transconductance amplifier is proportional to the first transconductance times the second transconductance times the amplifier output impedance times the second output impedance.
Claim 9
Dependent Claim
92 words
A CMOS transconductance type amplifier of the type having a differential input stage having a first transconductance and an amplifier output having an amplifier output impedance wherein the improvement comprises: a. a second amplifier stage having a second input, a second transconductance and a second output with a second output impedance; and b. a positive feedback path coupling the amplifier output to the second input, whereby the gain of the transconductance amplifier is proportional to the first transconductance times the second transconductance times the amplifier output impedance times the second output impedance.
Claim 10
Dependent Claim
18 words
The transconductance amplifier according to claim 7 wherein the first amplification means is a differential to differential amplifier.
Claim 11
Dependent Claim
18 words
The transconductance amplifier according to claim 8 wherein the second amplification means is a differential to common-mode amplifier.
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) | 1993-01-29 | 1993-07-31 | 1994-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-29 | 1997-07-31 | 1998-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-29 | 2001-07-31 | 2002-01-30 | $7700.00 | Window Closed / Lapsed |