Ambient light sensor
AssigneesSTMicroelectronics (Grenoble 2) SAS, STMicroelectronics (Alps) SAS
InventorsNicolas Moeneclaey, Laurent Vaccariello
Life of this patent
Estimating the term…
Abstract
An ambient light sensor includes pixels arranged in an array. Each pixel includes a doped insulated well of a first type, a pinned photodiode in the well, a doped region of a second type arranged in the well, a transfer gate coupling the photodiode to said region, and a first circuit applying a first or second potential to the well. A successive approximation analog-to-digital converter of the sensor has a node connected to the doped regions of the pixels, a switch applying a third potential to the node, a comparator coupled to the node, and a second circuit receiving an output of the comparator and controlling the first circuits to selectively apply the first and second potentials. A sensor control circuit controls the gates and the first switch.
Claims18
An ambient light sensor, comprising:
- a plurality of pixels, wherein each pixel comprises:
- a first doped insulated well of a first conductivity type;
- a pinned photodiode arranged in the first doped insulated well;
- a first doped region of a second conductivity type arranged in the first doped insulated well;
- a first transfer gate coupling the pinned photodiode to the first doped region;
- and
- a first circuit configured to selectively apply a first potential and a second potential to the first doped insulated well;
- a successive approximation analog-to-digital converter comprising:
- a first node connected to the first doped regions of all the pixels of the plurality of pixels;
- a first switch configured to selectively apply a third potential to the first node;
- a comparator having a first input coupled to the first node;
- and
- a second circuit configured to receive an output of the comparator and to control selective application of the first and second potentials to the first doped insulated well by the first circuits;
- and
- a control circuit configured to control actuation of the first transfer gates and control selective application of the third potential to the first node by the first switch.
An ambient light sensor, comprising:
- a plurality of pixels, wherein each pixel comprises:
- a first doped insulated well of a first conductivity type;
- a pinned photodiode arranged in the first doped insulated well;
- a first doped region of a second conductivity type arranged in the first doped insulated well;
- a first transfer gate coupling the pinned photodiode to the first doped region;
- and
- a first circuit configured to selectively apply a first potential and a second potential to the first doped insulated well;
- wherein the first doped regions of all the pixels of the plurality of pixels are connected to a first node;
- a control circuit configured to control actuation of the first transfer gates and control selective application of a third potential to the first node;
- a comparator having a first input coupled to the first node;
- and
- a processing circuit configured to receive an output of the comparator and to control selective application of the first and second potentials to the first doped insulated well by the first circuits based on the output of the comparator.
Dependencies are inferred from the claim text.