US4757270A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High gain feedback amplifier
Assignee: STC PLC
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Filing: 1986-10-20
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Granted: 1988-07-12
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Expires: 2006-10-20
Abstract
Abstract Feedforward of the source signal into the compensation mode of an operational amplifier produces more than an order of magnitude improvement in small-signal capability at high frequencies. The technique is useful for active filters and wideband amplifiers. Further improvement will be available using amplifiers designed for this approach.
Inventors
- 👤 George H. S. Rokos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 14:47
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/126; H03F; H03F1/00; H03F1/08; H03F1/083; H03F1/38; H03H11/0416
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
141 words
An amplifier circuit arrangement having an input and an output and incorporating first and second feedback loops and first and second gain sections each having an input and an output, the output of the first gain section being coupled to the input of the second gain section to form a composite amplifier, the first feedback loop being around the second gain section and connected to an input of the second gain section, and second feedback loop being around the composite amplifier and coupled between the input and output of the circuit arrangement, the feedback in the first and second loops being arranged so that the closed loop gain of the arrangement will remain at substantially the design value over a significant portion of the operating frequency range in the event that the feedback in either one of the loops is ineffective.
Claim 2
Dependent Claim
141 words
An amplifier circuit arrangement having an input and an output and incorporating first and second feedback loops and first and second gain sections each having an input and an output, the output of the first gain section being coupled to the input of the second gain section to form a composite amplifier, the first feedback loop being around the second gain section and connected to an input of the second gain section, and second feedback loop being around the composite amplifier and coupled between the input and output of the circuit arrangement, the feedback in the first and second loops being arranged so that the closed loop gain of the arrangement will remain at substantially the design value over a significant portion of the operating frequency range in the event that the feedback in either one of the loops is ineffective.
Claim 3
Dependent Claim
19 words
An arrangement according to claim 1 in which at least one of the feedback loop responses extends to D.C.
Claim 4
Dependent Claim
19 words
An arrangement according to claim 1 in which the external response of the amplifier circuit arrangement extends to D.C.
Claim 5
Dependent Claim
32 words
An arrangement according to any of claim 1 to 3 comprising several said second gain sections in one of the loops, all said second gain sections being contained within the first loop.
Claim 6
Dependent Claim
32 words
An arrangement according to any one of claims 1 to 3 wherein the input to at least one of the feedback loops is driven by the output of a fixed gain amplifier.
Claim 7
Dependent Claim
39 words
An arrangement according to claim 1, wherein the arrangement includes a multi-stage amplifier and at least one of the loops is taken round the multistage amplifier with a dominant pole provided by an amplification section of the multistage amplifier.
Claim 8
Dependent Claim
17 words
An amplifier according to claim 6 in which the second loop is implemented around said amplification section.
Claim 9
Dependent Claim
26 words
An amplifier according to claim 7 in which a feedback component of the second loop is a capacitor which also serves to define said dominant pole.
Claim 10
Dependent Claim
20 words
An amplifier according to claim 1 wherein at least one of the feedback loops is taken around an operational amplifier.
Claim 11
Dependent Claim
14 words
An amplifier according to claim 6, wherein the multistage amplifier is an operational amplifier.
Claim 12
Dependent Claim
13 words
An amplifier according to claim 6, wherein the multistage amplifier is an invertor.
Claim 13
Dependent Claim
11 words
An arrangement according to claim 1, constructed as an inverting amplifier.
Claim 14
Dependent Claim
11 words
An arrangement according to claims 1, constructed as an integrating amplifier.
Claim 15
Dependent Claim
12 words
An arrangement according to claims 1, constructed as a fixed gain amplifier.
Claim 16
Dependent Claim
14 words
An arrangement as defined in claim 1, constructed as a summing or differential 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) | 1991-07-12 | 1992-01-11 | 1992-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-07-12 | 1996-01-11 | 1996-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-07-12 | 2000-01-11 | 2000-07-12 | $7700.00 | Window Closed / Lapsed |