US3868583A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High-performance solid-state amplifier system
Assignee: Analog Devices Inc
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Filing: 1972-09-29
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Granted: 1975-02-25
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Expires: 1992-09-29
Abstract
Abstract A monolithic amplifier having a pair of input transistors forming a balanced differential input stage including a gain resistor arranged to conduct current proportional to the input signal and a feedback-controlled differentially-operated pair of current generators to maintain balanced current flow in the input transistors. Any unbalancing in the input stage is amplified to control a pair of balanced feedback transistors having a pair of current generators for setting the current flow therethrough, any unbalance between the feedback transistors being amplified to control both the input and the feedback current generators in unison to maintain null conditions in the feedback circuitry.
Inventors
- 👤 Heinrich F Krabbe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:45
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45098; H03F3/34; H03F3/343; H03F3/347; H03F3/45479; H03F3/45484; H03F3/45596; H03F3/456; H03F3/45618; H03F2203/00; H03F2203/45; H03F2203/45511; H03F2203/45521
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
188 words
A high-performance solid-state integrated-circuit amplifier comprising: an input section including a first differential amplifier having first and second differentially-operable transistor amplifiers; amplifier means responsive to the differential output of said input section to produce an output signal; first and second differentially-operable current sources connected in series with said first and second transistor amplifiers, respectively, to supply the currents flowing therethrough, respectively; control terminals for said first and second current sources respectively; a negative feedback circuit responsive to the output of said amplifier means and producing a feedback signal for said control terminals so as to tend to maintain the current through said first and second transistor amplifiers constant; said feedback circuit comprising a second differential amplifier including third and fourth differentially-operable transistor amplifiers and having its input coupled to the output of said amplifier means; and third and fourth differentially-operable current sources having third and fourth control terminals driven by said feedback signal together with said first and second control terminals respectively, said third and fourth current sources being connected in series with said third and fourth transistor amplifiers respectively to tend to maintain constant the currents therethrough.
Claim 2
Dependent Claim
188 words
A high-performance solid-state integrated-circuit amplifier comprising: an input section including a first differential amplifier having first and second differentially-operable transistor amplifiers; amplifier means responsive to the differential output of said input section to produce an output signal; first and second differentially-operable current sources connected in series with said first and second transistor amplifiers, respectively, to supply the currents flowing therethrough, respectively; control terminals for said first and second current sources respectively; a negative feedback circuit responsive to the output of said amplifier means and producing a feedback signal for said control terminals so as to tend to maintain the current through said first and second transistor amplifiers constant; said feedback circuit comprising a second differential amplifier including third and fourth differentially-operable transistor amplifiers and having its input coupled to the output of said amplifier means; and third and fourth differentially-operable current sources having third and fourth control terminals driven by said feedback signal together with said first and second control terminals respectively, said third and fourth current sources being connected in series with said third and fourth transistor amplifiers respectively to tend to maintain constant the currents therethrough.
Claim 3
Dependent Claim
28 words
An amplifier as in claim 1, including a gain-adjusting resistor connected between said first and second transistor amplifiers to control the relative gain produced by said input section.
Claim 4
Dependent Claim
28 words
An amplifier as in claim 2, including a scale resistor connected between said third and fourth transistor amplifiers to control the relative contribution thereof to the feedback action.
References Cited (Backward Citations)
US3434069A
Cited
US3733559A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-24 | 1978-08-26 | 1979-02-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-24 | 1982-08-26 | 1983-02-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-24 | 1986-08-26 | 1987-02-25 | $7700.00 | Window Closed / Lapsed |