US4400635A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wide temperature range switching circuit
Assignee: RCA Corp
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Filing: 1981-01-21
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Granted: 1983-08-23
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Expires: 2001-01-21
Abstract
Abstract In a circuit in which a current is supplied to an internal node and in which transistors have their base-to-emitter junctions connected in series between the internal node and a point of reference potential, (m-1) Schottky diodes, poled to conduct current in a direction opposite to that of the "m" base-to-emitter junctions, are connected in series between the internal node and an input terminal; where m is an integer greater than 2. The (m-1) diodes compensate for the change in the base-to-emitter voltages and extend the operating range of the circuit as a function of temperature. Also, the use of two or more diodes connected in series between the input terminal and the internal node decreases the capacitance between the input terminal and the internal node, and reduces the voltage swing at the internal node necessary to turn-on and turn-off the "m" base-to-emitter junctions.
Inventors
- 👤 James D. Mazgy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:26
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/08; H03K19/082; H03K19/088; H03K19/084; H03K19/0846
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
143 words
The combination comprising: first and second operating voltage terminals; a signal input terminal; an internal node; m transistors, each transistor having a base, an emitter, and a collector; means connecting the base-to-emitter paths of said m transistors in series between said internal node and said first operating voltage terminal, all the base-to-emitter paths being poled to conduct forward current in the same direction; first means for conducting a current connected between said second operating voltage terminal and said internal node; (m-1) diodes, poled to conduct forward current in a direction opposite to the forward current flow direction in the base-to-emitter paths to said m transistors, said (m-1) diodes being connected in series between said internal node and said input terminal; where m is an integer greater than 2; and means coupling the collectors of said m transistors to said second operating voltage terminal.
Claim 2
Dependent Claim
143 words
The combination comprising: first and second operating voltage terminals; a signal input terminal; an internal node; m transistors, each transistor having a base, an emitter, and a collector; means connecting the base-to-emitter paths of said m transistors in series between said internal node and said first operating voltage terminal, all the base-to-emitter paths being poled to conduct forward current in the same direction; first means for conducting a current connected between said second operating voltage terminal and said internal node; (m-1) diodes, poled to conduct forward current in a direction opposite to the forward current flow direction in the base-to-emitter paths to said m transistors, said (m-1) diodes being connected in series between said internal node and said input terminal; where m is an integer greater than 2; and means coupling the collectors of said m transistors to said second operating voltage terminal.
Claim 3
Dependent Claim
22 words
The combination as claimed in claim 1 wherein m is equal to 3, and wherein said (m-1) diodes comprise two Schottky diodes.
Claim 4
Dependent Claim
68 words
The combination as claimed in claim 2 wherein said m transistors includes first, second, and third transistors, wherein said first transistor is connected at its base to said internal node and at its emitter to the base of said second transistor, and wherein said third transistor is connected at its base to the emitter of said second transistor and at its emitter to said first operating voltage terminal.
Claim 5
Dependent Claim
95 words
The combination as claimed in claim 3 wherein said means for conducting a current includes a first resistor connected between said internal node and said second power terminal, and wherein the combination further includes: a second resistor connected between the collector of said second transistor and said second power terminal, a fourth transistor connected at its base to the collector of said second transistor, means for connecting the collector of said fourth transistor to said second operating voltage terminal; and means connecting the emitter of said fourth transistor to the collector of said third transistor.
Claim 6
Dependent Claim
59 words
The combination as claimed in claim 1 further including N input terminals, where N is an integer equal to, or greater than 1, (m-1) Schottky diodes per each one of said N additional input terminals; each one of said (m-1) Schottky diodes being connected in series between its respective one of said N input terminals and said internal node.
Claim 7
Dependent Claim
68 words
The combination as claimed in claim 5 wherein said m transistors includes first, second, and third transistors, wherein said first transistor is connected at its base to said internal node and at its emitter to the base of said second transistor, and wherein said third transistor is connected at its base to the emitter of said second transistor and at its emitter to said first operating voltage terminal.
Claim 8
Dependent Claim
36 words
The combination as claimed in claim 6 wherein an additional diode is connected between each one of said input terminals and the emitter of said first transistor poled in the same direction as said Schottky diodes.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-22 | 1987-02-21 | 1987-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-22 | 1991-02-21 | 1991-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-22 | 1995-02-21 | 1995-08-23 | $7700.00 | Window Closed / Lapsed |