US3883816A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential amplifier
Assignee: Unisys Corp
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Filing: 1974-03-11
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Granted: 1975-05-13
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Expires: 1994-03-11
Abstract
Abstract A transistorized differential amplifier which includes a pair of transistor elements and a pair of input terminals with a transformerless input coupling network for coupling each input terminal of the input terminal pair to both transistors. The input coupling network is configured to cause differential input signals to add across the base emitter junction of the transistor elements and common mode input signals to cancel across the base emitter junction of the transistors.
Inventors
- 👤 Donald T Best
- 👤 John B Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:11
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45479
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
153 words
A differential amplifier comprising: a pair of transistor elements each having base, emitter, and collector electrodes, separate impedance means connecting the respective emitter electrodes to a source of operating potential, output signal means connecting the collector electrodes to a source of operating potential, a pair of input signal terminals, a first signal path coupling the first of said pair of input signal terminals to the base electrode of a first one of said pair of transistors, a second signal path coupling the second of said input signal terminals to the base electrode of the second of said pair of transistors, a first emitter follower transistor cross coupling the said first input signal terminal to the emitter of said second transistor of said pair of transistors, and a second emitter follower transistor cross coupling the second of said pair of input terminals to the emitter electrode of the first of said pair of transistors.
Claim 2
Dependent Claim
153 words
A differential amplifier comprising: a pair of transistor elements each having base, emitter, and collector electrodes, separate impedance means connecting the respective emitter electrodes to a source of operating potential, output signal means connecting the collector electrodes to a source of operating potential, a pair of input signal terminals, a first signal path coupling the first of said pair of input signal terminals to the base electrode of a first one of said pair of transistors, a second signal path coupling the second of said input signal terminals to the base electrode of the second of said pair of transistors, a first emitter follower transistor cross coupling the said first input signal terminal to the emitter of said second transistor of said pair of transistors, and a second emitter follower transistor cross coupling the second of said pair of input terminals to the emitter electrode of the first of said pair of transistors.
References Cited (Backward Citations)
US3538447A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |