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Patent US5337007A successfully refreshed from Google Patents.
US5337007A
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High efficiency class AB transconductance amplifier
Assignee: Apple Inc
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Filing: 1993-11-04
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Granted: 1994-08-09
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Expires: 2013-11-04
Abstract
Abstract A class AB transconductance amplifier (200) has first and second differential input amplifier stages (100-112) adapted for receiving first and second differential input signals (Vin+, Vin-). First and second input cascode stages are coupled to the first and second differential input amplifier stages for providing first and second differential folded cascode signals. An output stage (113-118) is coupled to the first and second differential folded cascode signals providing an output signal indicative of a difference between the first and second differential input signals (Vin+, Vin-). A bias stage (101, 102) is coupled to said first and second differential input amplifier stages (103-104, 105-106) and the first and second input cascode stages bias the first and second differential input amplifier stages (100-112) to operate as a class AB folded cascode amplifier circuit (200). The bias stage generates class AB biasing signals.
Inventors
- 👤 Raymond L. Barrett, Jr.
- 👤 Barry W. Herold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:11
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/30; H03F3/3001; H03F3/45; H03F3/45071; H03F3/45076
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
126 words
A class AB transconductance amplifier, comprising: first and second differential input amplifier stages adapted for receiving first and second differential input signals; first and second input cascode stages coupled to said first and second differential input amplifier stages for providing first and second differential folded cascode signals; an output stage coupled to the first and second input cascode stages for providing an output signal indicative of a difference between the first and second differential input signals; and a bias stage coupled to said first and second differential input amplifier stages and said first and second input cascode stages for biasing the first and second differential input amplifier stages to operate as a class AB folded cascode amplifier circuit, said bias stage generating class AB biasing signals.
Claim 2
Dependent Claim
126 words
A class AB transconductance amplifier, comprising: first and second differential input amplifier stages adapted for receiving first and second differential input signals; first and second input cascode stages coupled to said first and second differential input amplifier stages for providing first and second differential folded cascode signals; an output stage coupled to the first and second input cascode stages for providing an output signal indicative of a difference between the first and second differential input signals; and a bias stage coupled to said first and second differential input amplifier stages and said first and second input cascode stages for biasing the first and second differential input amplifier stages to operate as a class AB folded cascode amplifier circuit, said bias stage generating class AB biasing signals.
Claim 3
Dependent Claim
36 words
The class AB transconductance amplifier according to claim 1, wherein the first and second input cascode stages comprise a current mirror, the current mirror receiving the class AB biasing signals for setting a common mode current.
Claim 4
Dependent Claim
40 words
The class AB transconductance amplifier according to claim 2, wherein the first and second input cascode stages comprise first and second folded transistors for generating a differential current, the first and second folded transistors receiving the class AB biasing signals.
Claim 5
Dependent Claim
41 words
The class AB transconductance amplifier according to claim 2, wherein the first and second input cascode stages comprise first and second folded transistors for generating a differential current, the first and second folded transistors being biased by class AB biasing signals.
Claim 6
Dependent Claim
37 words
The class AB transconductance amplifier according to claim 4 wherein the output stage receives the differential current from the first and second folded transistors, respectively, and converts the differential current into a single output current proportional thereto.
Claim 7
Dependent Claim
203 words
A class AB transconductance amplifier, comprising: first and second differential input amplifier stages adapted for receiving first and second differential input signals; first and second input cascode stages coupled to said first and second differential input amplifier stages for providing first and second differential folded cascode signals, said first and second input cascode stages comprise: a current mirror, the current mirror receiving a class AB biasing signals for setting a common mode current; and first and second folded transistors for generating a differential current, the first and second folded transistors receiving the class AB biasing signals; an output stage coupled to the first and second input cascode stages for providing an output signal indicative of a difference between the first and second differential input signals, said output stage receives the differential current from the first and second folded transistors, respectively, and converts the differential current into a single output current proportional thereto; and a bias stage coupled to said first and second differential input amplifier stages and said first and second input cascode stages for biasing the first and second differential input amplifier stages to operate as a class AB folded cascode amplifier circuit, said bias stage generating the class AB biasing signals.
Claim 8
Dependent Claim
203 words
A class AB transconductance amplifier, comprising: first and second differential input amplifier stages adapted for receiving first and second differential input signals; first and second input cascode stages coupled to said first and second differential input amplifier stages for providing first and second differential folded cascode signals, said first and second input cascode stages comprise: a current mirror, the current mirror receiving a class AB biasing signals for setting a common mode current; and first and second folded transistors for generating a differential current, the first and second folded transistors receiving the class AB biasing signals; an output stage coupled to the first and second input cascode stages for providing an output signal indicative of a difference between the first and second differential input signals, said output stage receives the differential current from the first and second folded transistors, respectively, and converts the differential current into a single output current proportional thereto; and a bias stage coupled to said first and second differential input amplifier stages and said first and second input cascode stages for biasing the first and second differential input amplifier stages to operate as a class AB folded cascode amplifier circuit, said bias stage generating the class AB biasing signals.
References Cited (Backward Citations)
US4958133A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-08-08 | 1998-02-07 | 1998-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-08 | 2002-02-07 | 2002-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-08 | 2006-02-07 | 2006-08-09 | $7700.00 | Window Closed / Lapsed |