Pixel unit and image sensor with high dynamic range

Abstract

The invention provides a pixel unit with a high dynamic range. The pixel unit is provided with a 4T structure; a reset transistor grid part of the pixel unit and a photodiode region are overlapped to form a first charge storage grid; and a row strobe transistor grid part and the photodiode region are overlapped to form a second charge storage grid. The invention also provides an image sensor with a high dynamic range. According to the pixel unit disclosed by the invention, the reset transistor grid part and the photodiode region are overlapped to form the first charge storage grid; the row strobe transistor grid part and the photodiode region are overlapped to form a second charge storage grid; and the first charge storage grid is controlled by using a reset signal and the second charge storage grid is controlled by using a row selection signal. The capability of a storage charge of the pixel unit is enhanced and the dynamic range of the pixel unit is widened; meanwhile, the difficulty of metal wire distribution is also reduced, the packing ratio of the pixel unit is increased and the chip area of the pixel unit is reduced.

Description

technical field [0001] The invention belongs to the field of CMOS (Complementary Metal Oxide Semiconductor, Complementary Metal Oxide Semiconductor) image sensors, and in particular relates to a high dynamic range pixel unit and an image sensor. Background technique [0002] In recent years, the CMOS image sensor industry has developed rapidly, and image sensor manufacturers have introduced products with superior performance and smaller chip areas. This puts forward higher requirements for the pixel unit, requiring the image sensor to achieve high dynamic range, high sensitivity, low noise and other characteristics under small-sized pixels. However, small pixels significantly restrict the high dynamic technical indicators of image sensors. Therefore, the use of large-sized pixels in high dynamic range image sensors makes it difficult to improve the cost performance of chips. [0003] Existing image sensor circuits all have a pixel array unit composed of multiple pixel units...

AI Technical Summary

Problems solved by technology

[0009] The present invention solves the technical problems of the existing high dynamic range image sensor pixel unit layout difficulty and large chip area, and provides a pixel unit and an image sensor that do not need to add additional MOS capacitance control signals to improve the dynamic range.

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