摘要
分辨率是CMOS图像传感器最重要的指标之一,分辨率越高,意味着像素阵列越大,像素阵列横向尺寸的增大对时序控制驱动电路的驱动能力提出了更高的要求,纵向尺寸增大也使得延迟影响行选信号的正常产生.本文研究了超大阵列CMOS图像传感器时序控制驱动电路.在像素阵列尺寸确定的情况下,采用左右两端同时驱动来提高控制电路的驱动能力,分析了寄生效应对时钟走线的影响,提出一种将移位寄存器时钟反向接入的方法,在不增加额外版图消耗的前提下提高了电路的可靠性.此外传感器尺寸较大,因此将时序控制驱动电路设计成可重复单元,再进行拼接.基于110 nm CMOS工艺,设计了超大阵列CMOS图像传感器时序控制驱动电路,并进行了2 k×2 k的样品芯片设计.配合2-share型5T像素结构,时序控制驱动电路可以实现滚筒模式、滚筒像素合并模式、全局模式3种模式的切换,并且可以开启高增益模μm式来获得低光照条件下的良好表现.样品芯片的像素尺寸为6μm×6μm,单侧行驱动电路尺寸为2 256μm×12 288μm,芯片整体尺寸19 300μm×19 500μm,帧频2帧/s,每行行选时间24.36μs,左右两端同时驱动,左右两侧信号差小于5 ns.
Resolution is one of the most important indicators of CMOS image sensors.The higher the resolution,the larger the pixel array is.The increase in the lateral size of the pixel array places higher requirements on the driving capability of the timing-driven circuit.The increase in the vertical size also causes the delay to affect the generation of selection signal.This paper studies the timing driven circuit of an ultra large array CMOS image sensor.The pixel array is simultaneously driven to improve the driving ability of the timing-driven circuit when the size of the pixel array is determined,and the influence of the parasitic effect on the control signal line is analyzed.Reversely inserting method of the shift register clock is proposed.The reliability of the circuit is improved without the additional layout consumption.In addition,the size of the sensor is large,so the timing-driven circuit is designed as a repeatable unit,and then spliced.Based on the 110 nm CMOS process,an ultra large array CMOS image sensor timing driven circuit is designed,and a 2 k×2 k sample chip design is performed.With the two-share 5T pixel structure,the timing-driven circuit can switch between Rolling mode,binning mode,and global mode,high gain mode can be turned on to obtain good performance in low-light conditions.The pixel size of the sample chip is 6μm×6μm,the size of the unilateral row driving circuit is 2256μm×12288μm,the size of the overall chip is 19300μm×19500μm,the frame rate is 2 frams per second,and the row selection time of each row is 24.36μs.The difference from left and right is less than 5 ns.
作者
高静
张天野
聂凯明
徐江涛
Gao Jing;Zhang Tianye;Nie Kaiming;Xu Jiangtao(School of Microelectronics,Tianjin University,Tianjin 300072,China;Tianjin Key Laboratory of Imaging and Sensing Microelectronic Technology,Tianjin 300072,China)
出处
《天津大学学报（自然科学与工程技术版）》
EI
CSCD
北大核心
2021年第1期75-81,共7页
Journal of Tianjin University：Science and Technology
