US3604944A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Mosfet comparator circuit
Assignee: Raytheon Co
•
Filing: 1970-04-09
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Granted: 1971-09-14
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Expires: 1990-04-09
Abstract
Abstract A metal oxide semiconductor field-effect transistor (MOSFET) digital comparator circuit of a type that can be constructed on a single semiconductor substrate. The circuit includes a series of exclusive OR gates, each of which accepts one bit from each of the binary words being compared. The exclusive OR gates provide an output signal when the bits being compared are not the same. The output signals from each of the exclusive OR gates are applied to a MOSFET NOR gate which will provide an output signal when all of the bits compare.
Inventors
- 👤 James L Gundersin
- 👤 Stephen P F Ma
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 21:00
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
202 words
A MOSFET comparator circuit as claimed in claim 1 wherein each of said plurality of MOSFET exclusive OR gates comprises: first and second MOSFETs interconnected in series circuit relationship for conducting the second signal level to the output when both bits are at the first signal level; a third MOSFET interconnected in parallel circuit relationship with said first and second MOSFETs for conducting the second signal level to the output when a first signal level is applied to its gate; a first MOS field-controlled resistor interconnected in series circuit relationship with said first and second MOSFETS and said third MOSFET for applying the first signal level to the output when the second signal level is not being conducted to the output by the first and second MOSFETs or the third MOSFET; fourth and fifth MOSFETs interconnected in parallel circuit relationship for conducting the second signal level to the gate of said third MOSFET when either of the bits are at the first signal level; a second MOS field-controlled resistor interconnected in series circuit relationship with said fourth and fifth MOSFETs for applying the first signal level to the gate of said third MOSFET when both bits are at the second signal level.
Claim 2
Dependent Claim
113 words
A MOSFET comparator circuit as claimed in claim 1 wherein said MOSFET NOR gate comprises: a plurality of MOSFETs interconnected in parallel circuit relationship, each of said plurality of MOSFETs being associated with an individual one of said plurality of MOSFET exclusive OR gates and being operable to conduct the second signal level to the output of said MOSFET NOR gate when the output of its associated MOSFET exclusive OR gate is at the first signal level; and a MOS field-controlled resistor for applying the first signal level to the output of said MOSFET NOR gate when all outputs of said plurality of MOSFET exclusive OR gates are at the second signal level.
References Cited (Backward Citations)
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US3252011A
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US3439185A
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US3479523A
Cited
US3475621A
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US3500062A
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US3365707A
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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) | 1974-09-13 | 1975-03-15 | 1975-09-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-09-13 | 1979-03-15 | 1979-09-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-09-13 | 1983-03-15 | 1983-09-14 | $7700.00 | Window Closed / Lapsed |