Patent US3564439A successfully refreshed from Google Patents.
US3564439A
Expired / Lapsed
US
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Differential amplifier
Assignee: AT&T Inc
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Filing: 1969-05-21
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Granted: 1971-02-16
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Expires: 1989-05-21
Abstract
Abstract A DIFFERENTIAL AMPLIFIER UTILIZES MATCHES TRANSISTOR CURRENT SOURCES IN BOTH THE EMITTER AND COLLECTOR CIRCUITS OF THE DIFFERENTIAL PAIR IN ORDER TO ACHIEVE HIGH COMMON MODE REJECTION AND DIFFERENTIAL GAIN WITHOUT SACRIFICING THE DIFFERENTIAL OUTPUT.
Inventors
- 👤 Tadikonda N Rao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 11:26
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45479
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-02-15 | 1974-08-17 | 1975-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-02-15 | 1978-08-17 | 1979-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-02-15 | 1982-08-17 | 1983-02-16 | $7700.00 | Window Closed / Lapsed |