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US 2021/0344862 A1Published application
Image sensor employing avalanche diode and pixel circuit and operating method thereof
AssigneePixart Imaging Inc.
InventorTso-Sheng TSAI
Life of this patent
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Abstract
There is provided an image sensor employing an avalanche diode. The image sensor includes a plurality of pixel circuits arranged in a matrix, a plurality of pulling circuits and a global current source circuit. Each of the plurality of pixel circuits includes a single photon avalanche diode and four P-type or N-type transistors. Each of the plurality of pulling circuits is arranged corresponding to one pixel circuit column. The global current source circuit is used to form a current mirror with each of the plurality of pulling circuits.
Claims13
An image sensor, comprising:
- a pixel array comprising a plurality of pixel circuits arranged in a matrix, each of the pixel circuits comprising an avalanche diode and a transistor, wherein the avalanche diode is connected to a gate of the transistor;
- and
- a plurality of pulling circuits each being configured to be coupled to a drain of the transistor of each pixel circuit of one pixel circuit column via a readout line.
A pixel circuit, comprising:
- an avalanche diode having an anode and a cathode, the cathode being connected to a positive bias voltage;
- a transistor, a gate of the transistor connected to the anode of the avalanche diode, and a source of the transistor connected to a ground voltage;
- and
- another transistor, a gate of the another transistor configured to receive an exposure signal, a source of the another transistor connected to a drain of the transistor, and a drain of the another transistor configured to generate an output voltage,
- wherein the drain of the another transistor is configured to be coupled to a pulling circuit outside the pixel circuit via a readout line to output the output voltage.
2 more elements
Dependencies are inferred from the claim text.