Ge Xiaoliang, Theuwissen Albert J P
Electronic Instrumentation Laboratory, Delft University of Technology, 2628 CD Delft, The Netherlands.
Harvest Imaging, 3960 Bree, Belgium.
Sensors (Basel). 2018 Feb 27;18(3):707. doi: 10.3390/s18030707.
This paper presents a temporal noise analysis of charge-domain sampling readout circuits for Complementary Metal-Oxide Semiconductor (CMOS) image sensors. In order to address the trade-off between the low input-referred noise and high dynamic range, a Gm-cell-based pixel together with a charge-domain correlated-double sampling (CDS) technique has been proposed to provide a way to efficiently embed a tunable conversion gain along the read-out path. Such readout topology, however, operates in a non-stationery large-signal behavior, and the statistical properties of its temporal noise are a function of time. Conventional noise analysis methods for CMOS image sensors are based on steady-state signal models, and therefore cannot be readily applied for Gm-cell-based pixels. In this paper, we develop analysis models for both thermal noise and flicker noise in Gm-cell-based pixels by employing the time-domain linear analysis approach and the non-stationary noise analysis theory, which help to quantitatively evaluate the temporal noise characteristic of Gm-cell-based pixels. Both models were numerically computed in MATLAB using design parameters of a prototype chip, and compared with both simulation and experimental results. The good agreement between the theoretical and measurement results verifies the effectiveness of the proposed noise analysis models.
本文介绍了用于互补金属氧化物半导体（CMOS）图像传感器的电荷域采样读出电路的时间噪声分析。为了解决低输入参考噪声和高动态范围之间的权衡问题，提出了一种基于跨导单元（Gm-cell）的像素与电荷域相关双采样（CDS）技术相结合的方法，以提供一种沿着读出路径有效嵌入可调转换增益的途径。然而，这种读出拓扑结构以非平稳大信号行为运行，其时间噪声的统计特性是时间的函数。传统的CMOS图像传感器噪声分析方法基于稳态信号模型，因此不能直接应用于基于Gm-cell的像素。在本文中，我们通过采用时域线性分析方法和非平稳噪声分析理论，开发了基于Gm-cell的像素中的热噪声和闪烁噪声分析模型，这有助于定量评估基于Gm-cell的像素的时间噪声特性。这两个模型均使用原型芯片的设计参数在MATLAB中进行了数值计算，并与仿真和实验结果进行了比较。理论结果与测量结果之间的良好一致性验证了所提出的噪声分析模型的有效性。
