IMAGING DEVICES AND METHODS FOR CHARGE TRANSFER
First Claim
Patent Images
1. A pixel circuit comprising:
- at least one pixel including a photosensor and a transfer transistor;
a charge storage node configured to be electrically connected to said photosensor when said transfer transistor is activated;
an amplifier having an input node and an output node, the input node electrically connected to said charge storage node; and
a feedback loop electrically connected between said input node and said output node of said amplifier, said feedback loop comprising a capacitance element and a reset transistor electrically connected in parallel to said capacitance element during operation of said pixel.
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Abstract
A pixel circuit having improved charge transfer including an amplifier having an input node electrically connected to a charge storage node of the pixel circuit, and a negative feedback control loop having a capacitance element electrically connected between the input node and an output node of said amplifier.
29 Citations
28 Claims
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1. A pixel circuit comprising:
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at least one pixel including a photosensor and a transfer transistor; a charge storage node configured to be electrically connected to said photosensor when said transfer transistor is activated; an amplifier having an input node and an output node, the input node electrically connected to said charge storage node; and a feedback loop electrically connected between said input node and said output node of said amplifier, said feedback loop comprising a capacitance element and a reset transistor electrically connected in parallel to said capacitance element during operation of said pixel. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of operating a pixel cell having a pixel circuit, said method comprising:
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resetting said pixel circuit by activating a reset transistor of said pixel circuit, said pixel circuit further comprising at least one photosensor, a charge storage node, an amplifier having an input connected to said charge storage node, and a capacitance element in a feedback loop of said amplifier; and amplifying a pixel signal of said pixel circuit by; deactivating said reset transistor, electrically connecting said at least one photosensor to said capacitance element and said floating diffusion node by activating said transfer transistor to form a capacitance divider between said at least one photosensor and said capacitance element, and amplifying a signal provided at an input of said amplifier to produce a pixel signal. - View Dependent Claims (16, 17, 18, 19)
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20. An imager comprising:
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a pixel array having a plurality of pixels, each of said pixels including at least one pair of a transfer transistor and a photosensor, said pixel array comprising; a circuit configured to output a pixel signal from at least one of said pixels, said circuit comprising; a charge storage node connected to said transfer transistor of said pixel; an amplifier having an input node and an output node, wherein the input node is electrically connected to said charge storage node; and a feedback loop electrically connected between said input node and said output node of said amplifier, said feedback loop comprising a capacitance element and a reset transistor electrically connected in parallel to said capacitance element during operation of said pixel; and sample-and-hold circuitry for sampling a reset voltage and an output voltage from said circuit. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28)
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Specification