共查询到17条相似文献,搜索用时 109 毫秒
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介绍了基于0.35μm工艺设计的单片CMOS图像传感器芯片.该芯片采用有源像素结构,像素单元填充因数可达到43%,高于通常APS结构像素单元30%的指标.此外还设计了一种数字动态双采样技术,相对于传统的双采样技术(固定模式噪声约为0.5%),数字动态双采样技术具有更简洁的电路结构和更好抑制FPN噪声的效果.传感器芯片通过MPW计划采用Chartered 0.35μm数模混合工艺实现.实验结果表明芯片工作良好,图像固定模式噪声约为0.17%. 相似文献
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介绍了基于0.35μm工艺设计的单片CMOS图像传感器芯片.该芯片采用有源像素结构,像素单元填充因数可达到43%,高于通常APS结构像素单元30%的指标.此外还设计了一种数字动态双采样技术,相对于传统的双采样技术(固定模式噪声约为0.5%),数字动态双采样技术具有更简洁的电路结构和更好抑制FPN噪声的效果.传感器芯片通过MPW计划采用Chartered 0.35μm数模混合工艺实现.实验结果表明芯片工作良好,图像固定模式噪声约为0.17%. 相似文献
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为了满足高动态范围高灵敏度的全局曝光模式下成像系统的需求,基于CIS-2521科学级CMOS图像传感器设计了一个相机系统,通过分析CIS-2521芯片像素读出结构特点,通过芯片内部模拟相关双采样与FPGA片内数字域相关双采样完成相关四采样算法,列向噪声去除效果明显。通过设计曲线拟合双增益通道图像数据合成输出,保证了系统成像有较高输出动态范围。相机常温下输出图像峰值信噪比达62.9dB,采用半导体制冷后输出图像峰值信噪比74.3dB。根据EMVA1288标准实测相机动态范围达到78.2dB,设计的相机系统实现了每秒50帧2 560×2 160像素,16bit深度高清晰度高动态范围图像的实时全局曝光成像输出,能够满足低照度条件下的高帧频高动态范围成像的需求。 相似文献
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设计了一种带隔直电容的交流耦合CTIA像元电路与数字相关双采样(DCDS)结构的CMOS图像传感器系统。在传统的CTIA像元电路中增加隔直电容,通过控制光电二极管的偏压,达到减小光电二极管暗电流的目的;同时采用片外数字CDS结构,通过在片外实现复位信号与像元积分信号的量化结果在数字域的减法,可以减小图像传感器像元的复位噪声和固定图案噪声(FPN)。基于0.35 m标准CMOS工艺对此CMOS图像传感器进行流片,像元阵列为256256,像元尺寸为16 m16 m。测试结果表明交流耦合CTIA像元电路可以将光电二极管的偏压控制在零偏点附近,此时其暗电流最小;采用了数字CDS结构后,图像传感器像元的时域噪声及固定图案噪声均有不同程度降低。 相似文献
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为了研究双存储像素的读出噪声对混合域实现图像块矩阵变换的CMOS图像传感器(CIS)产生的误差影响,对其进行噪声分析。结合双存储像素的工作时序,对实现图像块矩阵变换过程中由于多次采样和双路存储而增加的kTC噪声、源跟随器的1/f噪声和热噪声进行分析并建立数学模型,总结出双存储像素读出噪声对一次块矩阵变换的误差影响。以二维离散余弦变换为例,通过CHRT 0.35 m标准CMOS工艺电路仿真并结合matlab/simulink对比验证,得出增大存储电容、减小源跟随器宽长比可以降低由于像素读出噪声引起的误差。结果证明,此方法可以有效降低噪声,指导电路设计。 相似文献
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FU Xian-song YAO Su-ying YUAN Yi-dong XU Jiang-tao DING Ke YAN Kun-shan 《半导体光子学与技术》2008,14(3):153-157
The logarithmic response complementary metal oxide semiconductor (CMOS) image sensor provides a wide dynamic range, but its drawback is the lack of simple fixed pattern noise(FPN) cancellation scheme. Designed is a novel logarithmic active pixel sensor(APS) with high dynamic range and high output swing. Firstly, the operation principle of mixed-model APS is introduced. The pixel can work in three operation modes by choosing the proper control signals. Then, FPN sources of logarithmic APS are analyzed, and double-sampled technique is implemented to reduce FPN. Finally, according to the simulation results, layout is designed and has passed design rule check(DRC), electronic rule eheck(ERC) and layout versus schematic(LVS) verifications, and the post-simulation results are basically in agreement with the simulation results. Dynamic range of the new logarithmic APS can reach about 140 dB; and the output swing is about 750 inV. Results show that by using double sampled technique, most FPN is eliminated and the dynamic range is enhanced. 相似文献
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Kavadias S. Dierickx B. Scheffer D. Alaerts A. Uwaerts D. Bogaerts J. 《Solid-State Circuits, IEEE Journal of》2000,35(8):1146-1152
CMOS image sensors with logarithmic response are attractive devices for applications where a high dynamic range is required. Their strong point is the high dynamic range. Their weak point is the sensitivity to pixel parameter variations introduced during fabrication. This gives rise to a considerable fixed pattern noise (FPN) that deteriorates the image quality unless pixel calibration is used. In the present work a technique to remove the FPN by employing on-chip calibration is introduced, where the effect of threshold voltage variations in pixels is cancelled. An image sensor based on an active pixel structure with five transistors has been designed, fabricated, and tested. The sensor consists of 525×525 pixels measuring 7.5 μm×10 μm, and is fabricated in a 0.5-μm CMOS process. The measured dynamic range is 120 dB while the FPN is 2.5% of the output signal range 相似文献
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Tanzer M. Graupner A. Schuffny R. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2004,51(10):566-570
Three different current-mode-output CMOS image sensor structures comprising of a pixel cell and an appropriate readout circuit have been analyzed and compared with regard to their noise behavior, fixed-pattern noise (FPN), and the dynamic range. First, a standard integrating pixel cell with a readout circuit containing a voltage-to-current converter is proposed. Second, a pixel cell based on a switched current cell is analyzed. The third sensor cell uses a feedback loop to control the reverse bias voltage of the photodiode to reduce the settling time of the pixel cell and the influence of the photodiodes's dark current. The necessary amplifier is partly located in the pixel cell and partly in the readout circuit. In all sensors, correlated double sampling is used to suppress the FPN. 相似文献
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A technical investigation, research and im-plementation is presented to correct column fixed pattern noise and black level in large array Complementary metal oxide semiconductor (CMOS) image sensor. Through making a comparison among reported solution, and give large array CMOS image sensor design and considerations, according to our previous analysis on non-ideal factor and error source of piecewise Digital to analog converter (DAC) in multi-channels, an improving accurate piecewise DAC with adaptive switch technique is developed. The research theory has verified by a high dynamic range and low column Fixed pattern noise (FPN) CMOS image sensor prototype chip, which consisting of 8320×8320 pixel array was designed and fabricated in 55nm CMOS 1P4M standard process. The chip active area is 48mm×48mm with a pixel size of 5.7μm×5.7μm. The measured results achieved a high intrinsic dynamic range of 75dB, a low FPN and black level of 0.06%, a low photo response non-uniformity of 1.5% respectively, and an excellent raw sample image taken by the prototype sensor. 相似文献
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A High-Speed, High-Sensitivity Digital CMOS Image Sensor With a Global Shutter and 12-bit Column-Parallel Cyclic A/D Converters 总被引:4,自引:0,他引:4
Furuta M. Nishikawa Y. Inoue T. Kawahito S. 《Solid-State Circuits, IEEE Journal of》2007,42(4):766-774
This paper presents a high-speed, high-sensitivity 512times512 CMOS image sensor with column parallel cyclic 12-bit ADCs and a global electronic shutter. Each pixel has a charge amplifier for high charge-to-voltage conversion gain despite of using a large-size photodiode, and two sample-and-hold stages for the global shutter and fixed pattern noise (FPN) canceling. High-speed column-parallel cyclic ADC arrays with 12-bit resolution having a small layout size of 0.09 mm 2 are integrated at both sides of image array. A technique for accelerating the conversion speed using variable clocking and sampling capacitance is developed. A digital gain control function using 14-bit temporal digital code is also set in the column parallel ADC. The fabricated chip in 0.25-mum CMOS image sensor technology achieves the full frame rate in excess of 3500 frames/s. The in-pixel charge amplifier achieves the optical sensitivity of 19.9 V/lxmiddots. The signal full scale at the pixel output is 1.8 V at 3.3-V supply and the noise level is measured to be 1.8mVrms, and the resulting signal dynamic range is 60 dB 相似文献
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提出了一种应用于CMOS图像传感器数字双采样模数转换器(ADC)的可编程增益放大器(PGA)电路。通过增加失调采样电容,采集PGA运放和电容失配引入的失调电压,在PGA复位阶段和放大阶段进行相关双采样和放大处理,通过数字双采样ADC将两个阶段存储电压量化,并在数字域做差,降低了PGA电路引入的固定模式噪声。采用0.18μm CMOS图像传感器专用工艺进行仿真,结果表明:在输入失调电压-30~30mV变化区间,提出的PGA的输出失调电压可以降低到1mV以下,相比传统PGA输出失调电压随输入失调电压单倍线性关系而言大大降低了列固定模式噪声。 相似文献
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A 320×240 CMOS image sensor is demonstrated,which is implemented by a standard 0.6 μm 2P2M CMOS process.For reducing the chip area,each 2×2-pixel block shares a sample/hold circuit,analog-to-digital converter and 1-b memory.The 2×2 pixel pitch has an area of 40 μm×40 μm and the fill factor is about 16%.While operating at a low frame rate,the sensor dissipates a very low power by power-management circuit making pixel-level comparators in an idle state.A digital correlated double sampling,which eliminates fixed pattern noise,improves SNR of the sensor, and multiple sampling operations make the sensor have a wide dynamic range. 相似文献