Image sensor
AssigneeUniversité Catholique De Louvain
InventorsDavid BOL, Numa COUNIOT
Life of this patent
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Abstract
In an image sensor, a photo detector circuit applies a photo current to a capacitive node during a photo detection time interval. A front-end circuit comprises an input transistor having a control node that is coupled to the capacitive node. A switchable biasing arrangement puts the input transistor in a disabled state during the photo detection time interval. The input transistor is put in an enabled state after the photo detection time interval. This then causes the front-end circuit to provide an output signal that is representative of a voltage on the capacitive node after the photo detection time interval.
Claims11
An image sensor, comprising:
- a photo detector circuit arranged to apply a photo current to a capacitive node during a photo detection time interval;
- a front-end circuit comprising an input transistor having a control node that is coupled to the capacitive node;
- and
- a switchable biasing arrangement putting the input transistor in a disabled state during the photo detection time interval, and putting the input transistor in an enabled state after the photo detection time interval, causing the front-end circuit to provide an output signal that is representative of a voltage on the capacitive node after the photo detection time interval, wherein, in the disabled state, the input transistor is biased so that, when the photo detection time interval starts, each main node of the input transistor is at a voltage that approximates a reset voltage that is forced upon the capacitive node before the photo detection time interval starts.
Dependencies are inferred from the claim text.