Imager pixel with capacitance for boosting reset voltage
First Claim
Patent Images
1. A pixel circuit comprising:
- a photo-conversion device;
a floating diffusion region for receiving and storing charge from said photo-conversion device;
a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state;
a first capacitance circuit coupled to said floating diffusion region for storing charge received from said photo-conversion device;
a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and
a voltage boost circuit operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said voltage boost circuit comprises a second capacitance circuit.
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Accused Products
Abstract
A pixel cell in which a capacitance is coupled between a storage node and a row select transistor and another capacitance is coupled between a storage node and a voltage supply or ground source potential to boost a reset voltage.
55 Citations
39 Claims
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1. A pixel circuit comprising:
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a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitance circuit coupled to said floating diffusion region for storing charge received from said photo-conversion device; a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and a voltage boost circuit operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said voltage boost circuit comprises a second capacitance circuit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A pixel of an imaging device comprising:
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a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitor coupled to said floating diffusion region for storing charge received from said photo-conversion device; a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and a second capacitor operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state, said first and second capacitors having a common first electrode and respective second electrodes. - View Dependent Claims (12)
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13. A method of fabricating an integrated circuit comprising:
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forming a photo-conversion device; forming a floating diffusion region for receiving and storing charge from said photo-conversion device; forming a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; forming a first capacitance circuit coupled to said floating diffusion region for storing charge received from said photo-conversion device; forming a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and forming a voltage boost circuit operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said step of forming a voltage boost circuit comprises forming a second capacitance circuit. - View Dependent Claims (14, 15, 16, 17, 18)
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19. A method of operating a pixel comprising the steps of:
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receiving light in a photo-conversion device, said photo-conversion device converting said light into electrical charge; resetting a floating diffusion region to a predetermined reset voltage state; boosting a voltage on said floating diffusion region above said predetermined reset voltage state with a capacitance circuit operating in response to a switching state of a switching device; reading out said boosted reset voltage; storing charge from said photo-conversion device in said floating diffusion region and in another capacitance circuit coupled to said floating diffusion region; and reading out a signal based on stored charge at said floating diffusion region from said photo-conversion device. - View Dependent Claims (20, 21)
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22. A pixel circuit comprising:
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a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a transfer transistor for delivering said charge from said photo-conversion device to said floating diffusion region; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitor coupled to said floating diffusion region for storing charge received from said photo-conversion device; a source follower transistor coupled to said floating diffusion region for providing pixel output signals; a row select transistor for selectively operating said source follower transistor; and a voltage boost circuit operating in response to a switching state of said row select transistor for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said voltage boost circuit comprises a second capacitor. - View Dependent Claims (23, 24)
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25. A pixel circuit comprising:
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a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a transfer transistor coupled between the photo-conversion device and the floating diffusion region for delivering said charge from said photo-conversion device to said floating diffusion region; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitor coupled to said floating diffusion region for storing charge received from said photo-conversion device; a second capacitor operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state; a row select transistor coupled to said second capacitor; and a source follower transistor coupled to said second capacitor for reading out a signal based on charges stored at said floating diffusion region and said first capacitor.
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26. An imager comprising:
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an array of pixel circuits, at least one pixel circuit of said array comprising; a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitance circuit coupled to said floating diffusion region for storing charge received from said photo-conversion device; a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and a voltage boost circuit operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said voltage boost circuit comprises a second capacitance circuit. - View Dependent Claims (27, 28, 29, 30, 31, 32)
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33. A processing system comprising:
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a processor; and an imager electronically coupled to said processor, said imager comprising an array of pixel circuits, at least one pixel circuit of said array comprising; a photo-conversion device; a floating diffusion region for receiving and storing charge from said photo-conversion device; a reset transistor for resetting said floating diffusion region to a predetermined reset voltage state; a first capacitance circuit coupled to said floating diffusion region for storing charge received from said photo-conversion device; a readout circuit for reading out a signal based on charges stored at said floating diffusion region and said first capacitance circuit; and a voltage boost circuit operating in response to a switching state of a switching device of said pixel circuit for boosting a reset voltage on said floating diffusion region above said predetermined reset voltage state wherein said voltage boost circuit comprises a second capacitance circuit. - View Dependent Claims (34, 35, 36, 37, 38, 39)
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Specification