JSSC 2019第11期Data ConvertersCMOS Image Sensor

Energy-Efﬁcient Motion-Triggered IoT CMOS Image Sensor With Capacitor Array-Assi

提出一种低功耗运动触发CMOS图像传感器，适用于物联网应用。

10b ADC, 226 µVrms噪声, 63.6 pJ/frame/pixel, 14.4 µVrms·nJ FoM

低功耗CMOS图像传感器物联网运动触发电容阵列

▸创新点1：运动触发功能（系统创新）：通过基于运动的触发机制，仅在场景发生显著变化时触发全阵列捕获，显著降低功耗。该功能在32×20像素的子采样帧上运行，每帧仅消耗1.7 µJ，适用于低功耗物联网应用。

▸创新点2：电容阵列辅助SAR ADC（电路创新）：采用列并行电容阵列辅助电荷注入SAR ADC，实现10位操作，读取噪声低至226 µVrms。通过多采样技术，噪声可进一步降低至104 µVrms，提升图像质量。

▸创新点3：多采样降低噪声（方法创新）：通过多次采样技术有效降低ADC读取噪声，从226 µVrms降至104 µVrms，显著提高传感器信噪比和图像质量。

▸创新点4：高能效设计（系统创新）：在满阵列捕获模式下，ADC的能耗为63.6 pJ/帧/像素，ADC品质因数（FoM）为14.4 µVrms·nJ，达到同类最佳能效水平。

Abstract

We propose a low-power image sensor with a motion-based triggering feature for the Internet of Things (IoT) applications. The sensor supports the near-pixel [within analog-to-digital converter (ADC)] motion-detection mode run on a heavily subsampled frame (32 × 20 pixels, while consuming only 1.7 µJ/frame) to trigger full-array capture only when a signiﬁcant change has happened in the scene. Also, to maximize energy efﬁciency and image quality of the sensor, we propose a column- parallel capacit