US4951003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential transconductance circuit
Assignee: US Philips Corp
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Filing: 1989-05-16
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Granted: 1990-08-21
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Expires: 2009-05-16
Abstract
Abstract A amplifier circuit comprises first transistor (T 1 ) and a second transistor (T 2 ) whose emitters are each connected via a first resistors (R 1 ) to a point (2) which is connected to the power-supply terminal (3) by means of a current source (1). The bases of said transistors are connected to input terminals (4,5) and via a second resistor (R 2 ) each to the base of a third transistor (T 3 ) whose emitter is connected to the terminal (2). The linearity of the circuit is improved by arranging a fourth transistor (T 4 ) and a fifth transistor (T 5 ) in series with the collector-emitter paths of the first transistor (T 1 ) and the second transistor (T 2 ) which fourth and fifth transistor have their bases connected to a reference terminal (7) and have their emitters interconnected by means of a third resistor (R 3 ).
Inventors
- 👤 Willem De Jager
- 👤 Evert Seevinck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 14:54
CPC Classifications
H; H03; H03H; H03H11/00; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45085; H03F3/45089; H03F1/00; H03F1/32; H03F1/3211
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
175 words
A transconductance circuit comprising a first and a second transistor of a first conductivity type having their bases coupled to input terminals for receiving an input signal and having their emitters connected to a common point by means of first resistors, which common point is coupled to a first power-supply terminal by means of a current source, a third transistor of the first conductivity type whose collector-emitter path is arranged between a second power-supply terminal and the common point and having its base coupled to a tap of a voltage divider comprising two substantially identical second resistors arranged between the bases of the first and the second transistor, a fourth and a fifth transistor of the first conductivity type, having their collector-emitter paths arranged in series with the collector-emitter paths of the first and the second transistor respectively, having their bases coupled to a reference-voltage terminal, and having their collectors coupled to the output terminals for supplying an output signal, and a third resistor arranged between the emitters of the fourth and the fifth transistor.
Claim 2
Dependent Claim
175 words
A transconductance circuit comprising a first and a second transistor of a first conductivity type having their bases coupled to input terminals for receiving an input signal and having their emitters connected to a common point by means of first resistors, which common point is coupled to a first power-supply terminal by means of a current source, a third transistor of the first conductivity type whose collector-emitter path is arranged between a second power-supply terminal and the common point and having its base coupled to a tap of a voltage divider comprising two substantially identical second resistors arranged between the bases of the first and the second transistor, a fourth and a fifth transistor of the first conductivity type, having their collector-emitter paths arranged in series with the collector-emitter paths of the first and the second transistor respectively, having their bases coupled to a reference-voltage terminal, and having their collectors coupled to the output terminals for supplying an output signal, and a third resistor arranged between the emitters of the fourth and the fifth transistor.
Claim 3
Dependent Claim
58 words
A transconductance circuit as claimed in claim 1, further comprising a sixth and a seventh transistor of a second conductivity type, having their collector-emitter paths arranged between the respective emitters of the first and the second transistor and the first power-supply terminal, and having their bases coupled to the respective bases of the first and the second transistor.
Claim 4
Dependent Claim
23 words
A transconductance circuit as claimed in claim 1, wherein the current source is adapted to supply a current with a positive temperature coefficient.
References Cited (Backward Citations)
US32479A
Cited
US3489963A
Cited
DE2039399A1
Cited
USRE32479E
Cited
US4491803A
Cited
US4612513A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-20 | 1994-02-19 | 1994-08-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-20 | 1998-02-19 | 1998-08-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-20 | 2002-02-19 | 2002-08-21 | $7700.00 | Window Closed / Lapsed |