US3755807A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistor-ladder circuit
Assignee: Collins Radio Co
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Filing: 1972-02-15
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Granted: 1973-08-28
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Expires: 1992-02-15
Abstract
Abstract An accurate resistor-ladder circuit using field-effect transistor switches. The field-effect transistors have onresistances related to each other by a power of two whereby the cumulative resistances of said ladder produce accurate digitalto-analog conversion. Advantageously, the related resistance values of the FET''s are such as to lend themselves to integrated circuit implementation. Through use of ''''mirror'''' switch networks, deleterious effects of integrated circuit leakage currents are minimized.
Inventors
- 👤 J Brown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:29
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/66; H03M1/74
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
72 words
A resistor-ladder circuit as defined by claim 1 and including a second plurality of switch means comprising field-effect transistors, each of said second plurality of field-effect transistors being paired with one of said first plurality of transistors and being connected between the common terminal of the first transistor and the interconnected second plurality resistor and said common terminal, each of said second transistors having the same on-resistance as its paired first transistor.
Claim 2
Dependent Claim
14 words
A resistor-ladder circuit as defined by claim 1 wherein said field-effect transistors are MOSFET.
Claim 3
Dependent Claim
42 words
The circuit defined by claim 2 and further including an operational amplifier interconnected with said resistor-ladder circuit thereby comprising a digital-to-analog converter with said switch means controlled in accordance with a digital code whereby only one of each paired transistors is on.
Claim 4
Dependent Claim
44 words
A resistor-ladder circuit as defined by claim 3 wherein said switch means is part of a semiconductor integrated circuit with the related on-resistances being achieved by varied lengths of the emitter, gate, and source regions and by varied spacing between source and drain regions.
Claim 5
Dependent Claim
65 words
The circuit as defined by claim 4 and further including a second resistor-ladder circuit, and wherein semiconductor integrated circuit includes a second plurality of field-effect transistor switch means in pairs corresponding in number and configuration as said first plurality of field-effect transistor switch means, corresponding switch pairs of said first plurality and said second plurality of switch means lying in juxtaposition in said integrated circuit.
Claim 6
Dependent Claim
44 words
A resistor-ladder circuit as defined by claim 1 wherein said switch means is part of a semiconductor integrated circuit with the related on-resistances being achieved by varied lengths of the emitter, gate, and source regions and by varied spacing between source and drain regions.
Claim 7
Dependent Claim
65 words
The circuit as defined by claim 6 and further including a second resistor-ladder circuit, and wherein semiconductor integrated circuit includes a second plurality of field-effect transistor switch means in pairs corresponding in number and configuration as said first plurality of field-effect transistor switch means, corresponding switch pairs of said first plurality and said second plurality of switch means lying in juxtaposition in said integrated circuit.
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) | 1976-08-27 | 1977-02-26 | 1977-08-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-27 | 1981-02-26 | 1981-08-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-27 | 1985-02-26 | 1985-08-28 | $7700.00 | Window Closed / Lapsed |