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US4445051A Expired / Lapsed US ⏱️ 0.0 years remaining

Field effect current mode logic gate

Assignee: Samsung Electronics Co Ltd
•
Filing: 1981-06-26
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Granted: 1984-04-24
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Expires: 2001-06-26
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Abstract

Abstract Disclosed is a field effect current mode logic gate comprised of a current source for supplying a constant current, and a differential amplifier having first and second branches for passing respective portions of the constant current. The first branch includes a plurality of parallel-coupled or serially-coupled enhancement field effect transistors having a positive threshold voltage and having respective gates for receiving respective input logic signals; and the second branch includes a depletion field effect transistor having a negative threshold voltage, and a grounded gate. The magnitudes of the current portions in the first and second branches are representative of the magnitude of the input logic signals relative to the positive threshold voltage plus the absolute value of the negative threshold voltage.

Inventors

  • 👤 Mohamed I. Elmasry

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 14:00
CPC Classifications
H; H03; H03K; H03K19/00; H03K19/02; H03K19/08; H03K19/094; H03K19/0944; H03K19/09441; H03K19/09443

Claims Analysis

Total Claims: 13
Claim 1
Independent Claim 135 words
A field effect current mode logic gate comprised of: a field effect current source means for supplying a constant current; a field effect differential amplifier means having first and second branches coupled between said current source means and a power source means for passing respective portions of said constant current; said first branch including a plurality of parallel coupled enhancement field effect transistors having a positive threshold voltage and having respective gates for receiving respective input logic signals; and said second branch including a depletion field effect transistor having a negative threshold voltage and a grounded gate, whereby the magnitudes of said current portions in said first and second branches are representative of the magnitude of said input logic signals relative to said positive threshold voltage plus the absolute value of said negative threshold voltage.
Claim 2
Dependent Claim 135 words
A field effect current mode logic gate comprised of: a field effect current source means for supplying a constant current; a field effect differential amplifier means having first and second branches coupled between said current source means and a power source means for passing respective portions of said constant current; said first branch including a plurality of parallel coupled enhancement field effect transistors having a positive threshold voltage and having respective gates for receiving respective input logic signals; and said second branch including a depletion field effect transistor having a negative threshold voltage and a grounded gate, whereby the magnitudes of said current portions in said first and second branches are representative of the magnitude of said input logic signals relative to said positive threshold voltage plus the absolute value of said negative threshold voltage.
Claim 3
Dependent Claim 135 words
A field effect current mode logic gate comprised of: a field effect current source means for supplying a constant current; a field effect differential amplifier means having first and second branches coupled between said current source means and a power source means for passing respective portions of said constant current; said first branch including a plurality of serially coupled enhancement field effect transistors having a positive threshold voltage and having respective gates for receiving respective input logic signals; and said second branch including a depletion field effect transistor having a negative threshold voltage and a grounded gate, whereby the magnitudes of said current portions in said first and second branches are representative of the magnitude of said input logic signals relative to said positive threshold voltage plus the absolute value of said negative threshold voltage.
Claim 4
Dependent Claim 135 words
A field effect current mode logic gate comprised of: a field effect current source means for supplying a constant current; a field effect differential amplifier means having first and second branches coupled between said current source means and a power source means for passing respective portions of said constant current; said first branch including a plurality of serially coupled enhancement field effect transistors having a positive threshold voltage and having respective gates for receiving respective input logic signals; and said second branch including a depletion field effect transistor having a negative threshold voltage and a grounded gate, whereby the magnitudes of said current portions in said first and second branches are representative of the magnitude of said input logic signals relative to said positive threshold voltage plus the absolute value of said negative threshold voltage.
Claim 5
Dependent Claim 23 words
A field effect current mode logic gate according to claims 1 or 2 wherein said field effect transistors are metal-oxide-silicon field effect transistors.
Claim 6
Dependent Claim 23 words
A field effect current mode logic gate according to claims 1 or 2 wherein said field effect transistors are N-channel field effect transistors.
Claim 7
Dependent Claim 23 words
A field effect current mode logic gate according to claims 1 and 2 wherein said field effect transistors are P-channel field effect transistors.
Claim 8
Dependent Claim 39 words
A field effect current mode logic gate according to claims 1 and 2 wherein said plurality of enhancement field effect transistors and said depletion field effect transistor together have a speed power product of less than one pico joule.
Claim 9
Dependent Claim 30 words
A field effect current mode logic gate according to claims 1 or 2 wherein each enhancement field effect transistor of said plurality has a width/length ratio of at least 25/2.5.
Claim 10
Dependent Claim 42 words
A field effect current mode logic gate according to claims 1 and 2 wherein said current source is another depletion field effect transistor having a gate coupled to its source and to said gate of said previously recited depletion field effect transistor.
Claim 11
Dependent Claim 36 words
A field effect current mode logic gate according to claims 1 or 2 wherein said current source is another enhancement field effect transistor having a gate for receiving a control signal which initiates said constant current.
Claim 12
Dependent Claim 50 words
A field effect current mode logic gate according to claims 1 or 2 and further including an output means for generating output logic signals indicating which of said branches are passing the larger portion of said constant current and having a speed power product of less than two pico joules.
Claim 13
Dependent Claim 68 words
A field effect current mode logic gate according to claims 1 or 2 and further including a pair of output means for generating respective output logic signals indicating which of said branches is passing the larger portion of said constant current, with each output means of said pair including a field effect transistor, and with said field effect transistors in said pair of output means having cross-coupled gates.

References Cited (Backward Citations)

US3501647A Cited
US3619646A Cited
US3691401A Cited
US4074151A Cited
US4234803A Cited
US4239980A Cited
US4365316A Cited
US4333020A Cited
JPS55163917A Cited
JPS5631211A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1987-04-24 1987-10-24 1988-04-24 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1991-04-24 1991-10-24 1992-04-24 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1995-04-24 1995-10-24 1996-04-24 $7700.00 Window Closed / Lapsed

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