施工缝的留置与处理措施

施工缝是混凝土施工过程中的停歇位置,在现浇结构中,施工缝是不可避免的。但处理不好,极易成为结构上的薄弱部位,对结构抗震极为不利,所以在浇筑整体混凝土中,施工人员应严格按规范要求进行,认真对待施工缝的留置及处理,认识施工缝留置处理不当对工程质量的危害。     

用于降低高速CMOS图像传感器电荷转移时间的工艺技术

This paper proposes pixel process techniques to reduce the charge transfer time in high speed CMOS image sensors.These techniques increase the lateral conductivity of the photo-generated carriers in a pinned photodiode(PPD) and the voltage difference between the PPD and the floating diffusion(FD) node by controlling and optimizing the N doping concentration in the PPD and the threshold voltage of the reset transistor,respectively.The techniques shorten the charge transfer time from the PPD diode to the FD node effectively.The proposed process techniques do not need extra masks and do not cause harm to the fill factor.A sub array of 3264 pixels was designed and implemented in the 0.18 m CIS process with five implantation conditions splitting the N region in the PPD.The simulation and measured results demonstrate that the charge transfer time can be decreased by using the proposed techniques.Comparing the charge transfer time of the pixel with the different implantation conditions of the N region,the charge transfer time of 0.32 s is achieved and 31% of image lag was reduced by using the proposed process techniques.     

应用于高速CMOS图像传感器的具有动态功耗控制的12比特紧凑型列并行逐次逼近ADC

本文提出了一个应用于高速CMOS图像传感器的12比特列并行逐次逼近模数转换器。为了减小面积并使它的版图与两倍的像素间距相适应,采用了分段二进制权重开关电容数模转化器和交错结构的金属-氧化物-金属单位电容。为了消除单位电容上极板的寄生电容,提出了电场屏蔽的版图结构画法。提出了动态功耗控制技术,有效地降低了读出通道的功耗。用片外前台数字校准算法补偿开关电容数模转化器电容失配引起的非线性。芯片采用1P5M CMOS图像传感器工艺制造,其面积为20×2020μm2。采样率为833kS/s时,校准后的DNL、INL、ENOB分别为：0.9/-1 LSB、1/-1.1LSB、11.24比特。在1.8V的电源电压下,功耗为0.26 mW。随着帧率的减小,功耗线性减少。