US5844265A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sense amplifier for high-density imaging array
Assignee: Foveon Inc
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Filing: 1996-07-11
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Granted: 1998-12-01
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Expires: 2016-07-11
Abstract
Abstract A sense amplifier comprises an input node and an output node. An input transistor has a gate connected to the input node, a source connected to a first supply voltage rail, and a drain. A cascode transistor has a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node. A load transistor has a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail. The gates of the cascode transistor and the load transistor are biased such that the input transistor and the cascode transistor are operated near their threshold and the load transistor is operated above threshold. In a presently preferred embodiment of the present invention, the input transistor and the cascode transistor of the sense amplifier are wide and short, such that they operate in below threshold, whereas the load transistor is made long and relatively narrow, so that it operates above threshold.
Inventors
- 👤 Carver A. Mead
- 👤 Tobias Delbruck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 17:20
CPC Classifications
G; G11; G11C; G11C7/00; G11C7/06; G11C7/067; G11C27/00; G11C27/02; G11C27/024
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
114 words
A sense amplifier comprising: an input node; an output node; an input transistor having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; and a load transistor having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor.
Claim 2
Dependent Claim
114 words
A sense amplifier comprising: an input node; an output node; an input transistor having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; and a load transistor having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor.
Claim 3
Dependent Claim
32 words
The sense amplifier of claim 1 wherein the w/l ratio of the input transistor and the cascode transistor is at least 10 times greater than the w/l ratio of the load transistor.
Claim 4
Dependent Claim
42 words
The sense amplifier of claim 1 wherein the gates of the cascode transistor and the load transistor are biased such that the input transistor and the cascode transistor are operated near their threshold voltage and the load transistor is operated above threshold.
Claim 5
Dependent Claim
20 words
The sense amplifier of claim 1, further including a varactor element connected between said input node and said output node.
Claim 6
Dependent Claim
32 words
The sense amplifier of claim 4 wherein said varactor element comprises an MOS transistor having its gate connected to said input node and its source and drain connected to said output node.
Claim 7
Dependent Claim
32 words
The sense amplifier of claim 4 wherein said varactor element comprises an MOS transistor having its gate connected to said output node and its source and drain connected to said input node.
Claim 8
Dependent Claim
168 words
A sense amplifier for use in a photosensing array including a plurality of photosensing elements arranged in an array of rows and columns, each column having a column width, the sense amplifier comprising: an input node; an output node; an input transistor having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; a load transistor having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor; and wherein said sense amplifier may be disposed in an area on an integrated circuit, said area having a width no greater than the column width.
Claim 9
Dependent Claim
168 words
A sense amplifier for use in a photosensing array including a plurality of photosensing elements arranged in an array of rows and columns, each column having a column width, the sense amplifier comprising: an input node; an output node; an input transistor having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; a load transistor having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor; and wherein said sense amplifier may be disposed in an area on an integrated circuit, said area having a width no greater than the column width.
Claim 10
Dependent Claim
32 words
The sense amplifier of claim 7 wherein the w/l ratio of the input transistor and the cascode transistor is at least 10 times greater than the w/l ratio of the load transistor.
Claim 11
Dependent Claim
41 words
The sense amplifier of claim 7 wherein the gates of the cascode transistor and the load transistor are biased such that the input transistor and the cascode transistor are operated near their threshold and the load transistor is operated above threshold.
Claim 12
Dependent Claim
20 words
The sense amplifier of claim 7, further including a varactor element connected between said input node and said output node.
Claim 13
Dependent Claim
32 words
The sense amplifier of claim 10 wherein said varactor element comprises an MOS transistor having its gate connected to said input node and its source and drain connected to said output node.
Claim 14
Dependent Claim
32 words
The sense amplifier of claim 10 wherein said varactor element comprises an MOS transistor having its gate connected to said output node and its source and drain connected to said input node.
Claim 15
Dependent Claim
136 words
A sense amplifier comprising: an input node; an output node; an input transistor of a first conductivity type having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor of said first conductivity type having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; and a load transistor of a second conductivity type opposite that of said first conductivity type having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor.
Claim 16
Dependent Claim
136 words
A sense amplifier comprising: an input node; an output node; an input transistor of a first conductivity type having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor of said first conductivity type having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; and a load transistor of a second conductivity type opposite that of said first conductivity type having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor.
Claim 17
Dependent Claim
32 words
The sense amplifier of claim 13 wherein the w/l ratio of the input transistor and the cascode transistor is at least 10 times greater than the w/l ratio of the load transistor.
Claim 18
Dependent Claim
41 words
The sense amplifier of claim 13 wherein the gates of the cascode transistor and the load transistor are biased such that the input transistor and the cascode transistor are operated near their threshold and the load transistor is operated above threshold.
Claim 19
Dependent Claim
20 words
The sense amplifier of claim 13, further including a varactor element connected between said input node and said output node.
Claim 20
Dependent Claim
32 words
The sense amplifier of claim 16 wherein said varactor element comprises an MOS transistor having its gate connected to said input node and its source and drain connected to said output node.
Claim 21
Dependent Claim
32 words
The sense amplifier of claim 16 wherein said varactor element comprises an MOS transistor having its gate connected to said output node and its source and drain connected to said input node.
Claim 22
Dependent Claim
191 words
A sense amplifier for use in a photosensing array including a plurality of single-transistor photosensing elements arranged in an array of rows and columns, each column having a column width, the sense amplifier comprising: an input node; an output node; an input transistor of a first conductivity type having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor of said first conductivity type having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; a load transistor of a second conductivity type opposite that of said first conductivity type having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor; and wherein said sense amplifier may be disposed in an area on an integrated circuit, said area having a width no greater than the column width.
Claim 23
Dependent Claim
191 words
A sense amplifier for use in a photosensing array including a plurality of single-transistor photosensing elements arranged in an array of rows and columns, each column having a column width, the sense amplifier comprising: an input node; an output node; an input transistor of a first conductivity type having a gate connected to the input node, a source connected to a first supply voltage rail, and a drain; a cascode transistor of said first conductivity type having a gate connected to a cascode node, a source connected to the drain of the input transistor, and a drain connected to the output node; a load transistor of a second conductivity type opposite that of said first conductivity type having a gate connected to a bias node, a drain connected to the output node, and a source connected to a second supply voltage rail; wherein the w/l ratio of the input transistor and the cascode transistor is much greater than the w/l ratio of the load transistor; and wherein said sense amplifier may be disposed in an area on an integrated circuit, said area having a width no greater than the column width.
Claim 24
Dependent Claim
32 words
The sense amplifier of claim 19 wherein the w/l ratio of the input transistor and the cascode transistor is at least 10 times greater than the w/l ratio of the load transistor.
Claim 25
Dependent Claim
41 words
The sense amplifier of claim 19 wherein the gates of the cascode transistor and the load transistor are biased such that the input transistor and the cascode transistor are operated near their threshold and the load transistor is operated above threshold.
Claim 26
Dependent Claim
20 words
The sense amplifier of claim 19, further including a varactor element connected between said input node and said output node.
Claim 27
Dependent Claim
32 words
The sense amplifier of claim 22 wherein said varactor element comprises an MOS transistor having its gate connected to said input node and its source and drain connected to said output node.
Claim 28
Dependent Claim
32 words
The sense amplifier of claim 22 wherein said varactor element comprises an MOS transistor having its gate connected to said output node and its source and drain connected to said input node.
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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) | 2001-11-30 | 2002-06-01 | 2002-12-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-11-30 | 2006-06-01 | 2006-12-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-11-30 | 2010-06-01 | 2010-12-01 | $7700.00 | Window Closed / Lapsed |