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Patent US4647839A successfully refreshed from Google Patents.
US4647839A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High precision voltage-to-current converter, particularly for low supply voltages
Assignee: STMicroelectronics SRL
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Filing: 1984-02-08
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Granted: 1987-03-03
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Expires: 2004-02-08
Abstract
Abstract The common terminals of the two opposite transistors of a differential stage with an input signal represented by the voltage applied between the bases of the two transistors are connected to ground through two further transistors controlled by the current which passes through the above-mentioned transistors. The output signal is represented by the current which passes through one of said further transistors.
Inventors
- 👤 Marco Siligoni
- 👤 Pietro Consiglio
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:46
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
125 words
A high precision voltage-to-current converter, particularly for low supply voltages, comprising: a differential stage formed by a pair of PNP transistors having base terminals supplied with a voltage input signal, emitter terminals connected to each other through a coupling resistance and further connected to a supply line through a first pair of constant current generators, and collector terminals; a pair of NPN transistors having collector terminals connected to said emitter terminals of said PNP transistors, emitter terminals connected to ground and base terminals to said collector terminals of said PNP transistors; and a pair of second constant current generators interposed between said base terminals of said NPN transistors and ground, so that a collector-emitter current representing the converter output signal passes through said NPN transistors.
Claim 2
Dependent Claim
125 words
A high precision voltage-to-current converter, particularly for low supply voltages, comprising: a differential stage formed by a pair of PNP transistors having base terminals supplied with a voltage input signal, emitter terminals connected to each other through a coupling resistance and further connected to a supply line through a first pair of constant current generators, and collector terminals; a pair of NPN transistors having collector terminals connected to said emitter terminals of said PNP transistors, emitter terminals connected to ground and base terminals to said collector terminals of said PNP transistors; and a pair of second constant current generators interposed between said base terminals of said NPN transistors and ground, so that a collector-emitter current representing the converter output signal passes through said NPN transistors.
Claim 3
Dependent Claim
20 words
A converter according to claim 1, wherein said first and second pairs of current generators are constituted by electric resistances.
Claim 4
Dependent Claim
90 words
A converter according to claim 1, having a mirror associated therewith to form a current amplifier, said mirror including a further PNP transistor having an emitter terminal connected to a supply line and a diode interposed between a base terminal of said further PNP transistor and said supply line, said base terminal of said further PNP transistor and a collector terminal of said further PNP transistor being connected to ground through respective further PNP transistors having base terminals connected to the base terminals of said NPN transistors of the converter.
Claim 5
Dependent Claim
105 words
A converter according to claim 1, having a linearization circuit associated therewith to form a signal multiplier, said linearization circuit including a further PNP transistor having an emitter terminal connected to a supply line, a diode interposed between a base terminal of said further PNP transistor and said supply line, and a pair of further NPN transistors having collector terminals respectively connected to said base terminal of said further PNP transistor and a collector terminal of said further PNP transistor, emitter terminals connected to ground through a further current generator and base terminals connected to the base terminals of said NPN transistors of the converter.
Claim 6
Dependent Claim
25 words
A converter according to claim 4, wherein a further diode is interposed between the emitter terminals of said NPN transistors of the converter and ground.
Claim 7
Dependent Claim
68 words
A converter according to claim 4, wherein said base terminals of said further NPN transistors of the linearization circuit are connected to the base terminals of said NPN transistors of the converter through respective PNP transistors having emitter terminals connected to the supply line through additional current generators, collector terminals connected to ground and base terminals connected to the base terminals of said NPN transistors of the converter.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |