Patent US4392067A successfully refreshed from Google Patents.
US4392067A
Expired / Lapsed
US
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Logic select circuit
Assignee: Motorola Solutions Inc
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Filing: 1981-02-18
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Granted: 1983-07-05
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Expires: 2001-02-18
Abstract
Abstract A circuit for use with interface systems for providing a threshold setting function wherein the system can be made to interface with T 2 L or CMOS logic with either 5 or 15 volt power supply capabilities. The circuit comprises a pair of matched resistors coupled in series to one another. The first one of the resistors is returned to a select terminal via a first pair of diodes. The second resistor is returned to a terminal at which may be supplied a ground reference potential via a second pair of diodes. A source of current is provided that is coupled to the interconnection of the second resistor with the second pair of diodes. A threshold output is provided to the interface system at the interconnection between the serially connected resistors.
Inventors
- 👤 John J. Price, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 23:53
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/0175; H03K19/017509
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
A logic select circuit for providing a multi-level logic threshold signal at an output thereof, comprising: first diode means coupled between a first terminal and a first circuit node; second diode means coupled between a second terminal at which is supplied a ground reference potential and a second circuit node; circuit means coupled between said first and second circuit nodes and to the output of the logic select circuit; and current source means coupled to said second circuit node for providing a predetermined current thereto such that a first logic threshold signal of a first level is produced at the output of the logic select circuit and second logic threshold signal of a second level is produced when said first terminal is connected to a source of operating potential supplied to the logic select circuit.
Claim 2
Dependent Claim
135 words
A logic select circuit for providing a multi-level logic threshold signal at an output thereof, comprising: first diode means coupled between a first terminal and a first circuit node; second diode means coupled between a second terminal at which is supplied a ground reference potential and a second circuit node; circuit means coupled between said first and second circuit nodes and to the output of the logic select circuit; and current source means coupled to said second circuit node for providing a predetermined current thereto such that a first logic threshold signal of a first level is produced at the output of the logic select circuit and second logic threshold signal of a second level is produced when said first terminal is connected to a source of operating potential supplied to the logic select circuit.
Claim 3
Dependent Claim
31 words
The logic select circuit of claim 1 wherein: said first diode means includes first and second serially connected diodes; and said second diode means includes third and fourth serially connected diodes.
Claim 4
Dependent Claim
46 words
The logic select circuit of claim 2 wherein said circuit means includes: a first resistor; and a second resistor connected in series with said first resistor with the output of the logic select circuit being coupled to the interconnection point between said first and second resistors.
Claim 5
Dependent Claim
205 words
A monolithic integrated logic select circuit for providing multiple logic threshold signals to an utilization means, comprising: first and second circuit means serially connected between a first terminal and a second terminal, said first and second circuit means having substantially identical voltage/current transfer characteristics wherein a first logic threshold signal of a first level is produced at the interconnection between said first and second circuit means when an operating potential is applied at said first terminal, said first logic threshold signal having a magnitude substantially equal to one-half said operating potential, said second terminal receiving a ground reference potential; current source means for supplying a current of predetermined magnitude to said second circuit means wherein a second logic threshold signal of a second level is produced at the interconnection between said first and second circuit means whenever said first terminal is open-circuited; output circuit means coupled to the interconnection between said first and second circuit means for supplying said first and second logic threshold signals to the utilization means; and said first circuit means including a first diode, a second diode and a first resistor serially connected between said first terminal and a circuit node, said circuit node being coupled to said output circuit means.
Claim 6
Dependent Claim
205 words
A monolithic integrated logic select circuit for providing multiple logic threshold signals to an utilization means, comprising: first and second circuit means serially connected between a first terminal and a second terminal, said first and second circuit means having substantially identical voltage/current transfer characteristics wherein a first logic threshold signal of a first level is produced at the interconnection between said first and second circuit means when an operating potential is applied at said first terminal, said first logic threshold signal having a magnitude substantially equal to one-half said operating potential, said second terminal receiving a ground reference potential; current source means for supplying a current of predetermined magnitude to said second circuit means wherein a second logic threshold signal of a second level is produced at the interconnection between said first and second circuit means whenever said first terminal is open-circuited; output circuit means coupled to the interconnection between said first and second circuit means for supplying said first and second logic threshold signals to the utilization means; and said first circuit means including a first diode, a second diode and a first resistor serially connected between said first terminal and a circuit node, said circuit node being coupled to said output circuit means.
Claim 7
Dependent Claim
62 words
The logic select circuit of claim 4 wherein said second circuit means includes a third diode, a fourth diode, said third and fourth diode being serially coupled to said second terminal and a second resistor coupled between said serially coupled third and fourth diodes and said circuit node, said current source means being coupled to said third and fourth serially coupled 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) | 1986-07-04 | 1987-01-03 | 1987-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-04 | 1991-01-03 | 1991-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-04 | 1995-01-03 | 1995-07-05 | $7700.00 | Window Closed / Lapsed |