US3845404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential amplifier having active feedback circuitry
Assignee: Individual
•
Filing: 1972-06-16
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Granted: 1974-10-29
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Expires: 1992-06-16
Abstract
Abstract Common-mode and differential-mode active electrical and electrooptic feedback systems are formed with a plurality of physically interchangeable circuits. One of a plurality of input stage amplifiers can be connected to one of a plurality of loads through intermediate and output stage amplifiers. A plurality of interchangeable feedback stage amplifiers are then connected from various stage amplifiers back to the input stage amplifier. Such arrangements control the gain and the input and output impedances of the system independently for both the common and differential modes.
Inventors
- 👤 T Trilling
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:21
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/04; H03F3/08; H03F3/085; H03F3/45; H03F3/45071; H03F3/45479
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
133 words
A differential amplifier system comprising: an input circuit connected to receive an input signal having common mode and differential mode components, and common mode and differential mode feedback signals for controlling the impedance and gain of said input circuit, and for supplying a first output signal; an output circuit connected to receive and amplify said first output signal, and for supplying a second output signal having both common mode and differential mode components to a load and a third output siGnal; first active feedback means connected to receive and amplify the second output signal and for supplying only the differential mode feedback signal to said input circuit; and second active feedback means connected to receive and amplify the third output signal and for supplying the common mode feedback signal to said input circuit.
Claim 2
Dependent Claim
133 words
A differential amplifier system comprising: an input circuit connected to receive an input signal having common mode and differential mode components, and common mode and differential mode feedback signals for controlling the impedance and gain of said input circuit, and for supplying a first output signal; an output circuit connected to receive and amplify said first output signal, and for supplying a second output signal having both common mode and differential mode components to a load and a third output siGnal; first active feedback means connected to receive and amplify the second output signal and for supplying only the differential mode feedback signal to said input circuit; and second active feedback means connected to receive and amplify the third output signal and for supplying the common mode feedback signal to said input circuit.
Claim 3
Dependent Claim
83 words
A differential amplifier system according to claim 1, wherein said first active feedback means further comprises: attenuation means connected to receive the output circuit second output signal for decreasing the input circuit differential mode feedback signal and for providing an output signal indicative of the differential mode gain of said amplifier system; and current isolation means connected to receive the attenuation means output signal for removing the common mode component thereof and for providing the first active feedback means differential mode feedback signal.
Claim 4
Dependent Claim
64 words
A differential amplifier system according to claim 2 wherein said input circuit further comprises: a pair of differentially-connected multi-emitter transistors having the bases connected to receive the input signal, respective ones of said emitters connected to receive the differential mode feedback signal, respective other of said emitters operatively connected to receive the common mode feedback signal, and the collectors supplying the first output signal.
Claim 5
Dependent Claim
51 words
A differential amplifier system according to claim 3, wherein said second active feedback means further comprises: a transistor having the base operatively connected to receive the third output signal, the emitter operatively connected to a voltage biasing source, and the collector supplying the common mode feedback signal to said input circuit.
Claim 6
Dependent Claim
57 words
A differential amplifier system according to claim 2, wherein said input circuit further comprises: a pair of differentially connected transistors having each of the bases commonly connected to receive both the input signal and the differential mode feedback signal, emitters commonly connected to receive the common mode feedback signal, and the collectors supplying the first output signal.
Claim 7
Dependent Claim
51 words
A differential amplifier system according to claim 5, wherein said second active feedback means further comprises: a transistor having the base operatively conneced to receive the third output signal, the emitter operatively connected to a voltage biasing source, and the collector supplying the common mode feedback signal to said input circuit.
References Cited (Backward Citations)
US3427560A
Cited
US3480872A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |