4 transistors 4 shared step & repeat unit cell and 4 transistors 4 shared image sensor including the unit cells

Abstract

A 4T-4S step & repeat unit cell obtained by combining four image sensor unit cells each including four transistors and a 4T-4S image sensor including the 4T-4S step & repeat unit cell are provided. The 4T-4S step & repeat unit cell includes first and second shared image sensor unit cells. The first shared image sensor unit cell includes first and third photodiodes and five transistors. The second shared image sensor unit cell includes second and fourth photodiodes and five transistors. The second photodiode is disposed over the first photodiode. The third photodiode is disposed at a side of the second photodiode. A terminal of each of the fourth photodiode is connected to a first voltage source. Signals corresponding to images incident onto the first and third photodiodes are output through a first common detection line OUT1. Signals corresponding to images incident onto the second and fourth photodiodes are output through a second common detection line OUT2.

Description

technical field [0001] The present invention relates to an image sensor, and more particularly, to a 4T-4S step-and-repeat unit cell obtained by combining four image sensor unit cells each including four transistors. Background technique [0002] figure 1 A 4T-2S image sensor circuit obtained by combining two image sensor circuits each including four transistors is illustrated. [0003] refer to figure 1 , a 4T-4S image sensor circuit 100 is obtained by combining two image sensor unit cells 10 and 20 each including four transistors. That is, the reset transistors M12 and M22, the switching transistors M13 and M23, and the selection transistors M14 and M24 are shared by two image sensor circuits each including four transistors. The 4T-2S image sensor circuit 100 senses and transfers charges corresponding to image signals generated by two photodiodes PD1 and PD2 through three shared transistors MC2 , MC3 and MC4 and two transfer transistors M11 and M21 . [0004] Here, sin...

AI Technical Summary

Problems solved by technology

Therefore, when a problem occurs in one of the four units, the other units cannot be used

This seriously affects the yield of the product

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