CMOS图像传感器中低FPN列读出电路的设计  

Design for Column Readout Circuit with FPN Reduction in CMOS Image Sensor

作　　者：林晓志[1] 张生才[1] 姚素英[1] 徐江涛[1] 

机构地区：[1]天津大学专用集成电路设计中心,天津300072

出　　处：《传感技术学报》2006年第3期697-701,共5页Chinese Journal of Sensors and Actuators

基　　金：天津市科技攻关项目(033183911)

摘　　要：针对CMOS有源像素传感器,提出一种降低固定模式噪声(FPN)的列读出电路。通过对普通列读出电路进行改进,在双采样电路基础上,增加了失调电压补偿过程。数学分析和电路模拟结果表明双采样技术可以消除像素内产生的固定模式噪声,采用失调电压补偿技术可以将运算放大器带来的列FPN从毫伏级降为微伏级。该电路已应用于640×480CMOS图像传感器中,满足低功耗(16.5μW)和窄列宽(8μm)的要求,并在CHRT0.35μm工艺下成功流片,测试结果表明电路可将固定模式噪声降低到1mV以下,有效改善电路性能。A column readout circuit to reduce fixed pattern noise（FPN）for CMOS active pixel sensor imagers is presented. The traditional readout circuit is improved by offset compensation based on double sampling technique. The mathematical analysis and circuit simulation suggest that the FPN arising from the pixel parameter variations can be eliminated by double sampling, and the column FPN due to the operational amplifier can be reduced from milivolt to microvolt by offset compensation technique. The circuit is implanted in the system of 640 × 480 CMOS imager sensor, and achieves low power（16.5μW） and small column pitch（8μW）. It is successfully taped out with CHRT 0. 35μm process, the test result shows that FPN was reduced under 1 mV, which will improve circuit performance.

关 键 词：CMOS图像传感器 固定模式噪声 双采样 失调电压补偿 

分 类 号：TN43[电子电信—微电子学与固体电子学]