US4528516A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential amplifier with dynamic thermal balancing
Assignee: St Clair Intellectual Property Consultants Inc
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Filing: 1983-08-01
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Granted: 1985-07-09
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Expires: 2003-08-01
Abstract
Abstract A differential amplifier is provided with means to control the collector-to-emitter voltage thereof proportionately with quiescent current therethrough to dynamically maintain thermal balance therebetween when the gain setting is changed.
Inventors
- 👤 Thomas C. Hill, III
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:35
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3211; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45098; H03F3/45103; H03G; H03G1/00; H03G1/0005; H03G1/0017; H03G1/0023; H03G1/04; H03F2203/00; H03F2203/45; H03F2203/45302; H03F2203/45494; H03F2203/45498
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
124 words
A variable-gain differential amplifier with dynamic thermal balancing, comprising: means for providing a selectable gain control voltage and an absolute value voltage which is proportional to the absolute value of said gain control voltage; at least one pair of emitter-coupled transistors, each having a base for receiving input signals and a collector coupled to a load resistor; and variable current generator means responsive to said gain control voltage coupled to said emitters of said emitter-coupled transistors for providing selectable quiescent current through said transistors; wherein said absolute value voltage is coupled to both bases of said emitter-coupled pair of transistors thereby to control the collector-to-emitter voltage of said transistors such that said collector-to-emitter voltage is changed proportionately with changes in said selectable quiescent current.
Claim 2
Dependent Claim
124 words
A variable-gain differential amplifier with dynamic thermal balancing, comprising: means for providing a selectable gain control voltage and an absolute value voltage which is proportional to the absolute value of said gain control voltage; at least one pair of emitter-coupled transistors, each having a base for receiving input signals and a collector coupled to a load resistor; and variable current generator means responsive to said gain control voltage coupled to said emitters of said emitter-coupled transistors for providing selectable quiescent current through said transistors; wherein said absolute value voltage is coupled to both bases of said emitter-coupled pair of transistors thereby to control the collector-to-emitter voltage of said transistors such that said collector-to-emitter voltage is changed proportionately with changes in said selectable quiescent current.
References Cited (Backward Citations)
US3900801A
Cited
US4169247A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-08 | 1989-01-07 | 1989-07-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-08 | 1993-01-07 | 1993-07-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-08 | 1997-01-07 | 1997-07-09 | $7700.00 | Window Closed / Lapsed |