Global shutter pixel unit of complementary metal oxide semiconductor (CMOS) image sensor

Abstract

The invention discloses a global shutter pixel unit of a complementary metal oxide semiconductor (CMOS) image sensor. The global shutter pixel unit comprises a photoelectric diode, a signal readout circuit, a signal amplifying circuit, a signal sampling and retaining circuit and a signal output circuit which are connected with one another, wherein the photoelectric diode is used for acquiring original information of an incident light ray and converting an acquired target image light signal into an electric signal; the signal readout circuit is used for reading the electric signal subjected to photoelectric conversion in the photoelectric diode out, and storing the electric signal in a node FD; the signal in the node FD is amplified by the signal amplifying circuit; the signal amplifying circuit comprises an operational amplifier which is used for amplifying the signal stored in the node FD; the amplified signal is output to the signal sampling and retaining circuit; the signal sampling and retaining circuit is used for sampling and retaining the signal output by the signal amplifying circuit; and the signal output circuit is used for sampling and outputting the signal which is sampled and retained in the signal sampling and retaining circuit. By the global shutter pixel unit, the problem of large noise of the existing global shutter pixel in the CMOS image sensor can be solved.

Description

technical field [0001] The invention relates to the technical field of CMOS image sensors, in particular to a global exposure pixel unit of a CMOS image sensor. Background technique [0002] CMOS image sensors have been widely used in military and civilian fields, such as military reconnaissance, space remote sensing imaging, aircraft navigation, digital cameras, security monitoring and automatic control, etc. CMOS image sensors have a tendency to replace CCDs in both military and civilian markets. [0003] For CMOS image sensors, there are usually two exposure methods: rolling exposure (Rolling Shutter) and global exposure (Global Shutter). The CMOS image sensor with global exposure method is more conducive to the imaging of high-speed moving objects. In the prior art, the global exposure CMOS image sensor mainly adopts the five-tube (5T) pixel unit in the US patent No. US 7,129,979B1. The five-tube global exposure pixel unit mainly has the following disadvantages: [0...

AI Technical Summary

Problems solved by technology

[0008] In view of this, the main purpose of the present invention is to provide a CMOS image sensor global exposure with low noise, large dynamic range, small pixel area, and high light-shielding efficiency in order to solve the problem of large pixel noise in the existing global exposure in the CMOS image sensor. pixel unit

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