Ramp Noise Projection in CMOS Image Sensor Single-Slope ADCs
Ramp Noise Projection in CMOS Image Sensor Single-Slope ADCs
复制标题
CMOS 图像传感器单斜率 ADC 中的斜坡噪声投影
DOI：
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
B. Choubey
中科院分区：
文献类型：
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作者：
D. Levski;M. Wäny;B. Choubey
介绍了常规单斜坡斜坡模数转换器（ADC）输出端斜坡参考电压及其投影的噪声分析。本文分析了列并行CMOS图像传感器ADC连续时间斜坡阶段的基准电压噪声来源及其对ADC最终输出噪声的影响。首先对基于连续时间斜坡基准的随机游走噪声进行了理论建模。斜坡上的噪声不会直接增加ADC的输出噪声，但会根据给定的斜坡上升时间条件进行调制和投射。测试结果表明，与信号相关的输出噪声与所提出的随机游走噪声模型的噪声增加率是一致的。
Noise analysis of the ramp reference voltage and its projection at the output of a conventional single-slope ramp analog-to-digital converter (ADC) is presented. This paper gives insight on the reference voltage noise origins during the continuous-time ramping phase of column-parallel CMOS image sensor ADCs, as well as its effect on the final ADC output noise. Theoretical modeling of an occurring random walk noise on continuous-time-based ramp references is presented first. Noise on the ramp does not directly add to the output noise of the ADC, but it is modulated and projected subject to given ramp rise time conditions. Test measurements show that the signal-dependent output noise is consistent with the rate of noise increase by the proposed random walk noise model.