全局/滚动曝光兼容高动态抗辐照CMOS图像传感器设计

CMOS Image Sensor Design with Global/Rolling Exposure Compatibility, High Dynamics, and Radiation Resistance

摘要:

针对高速目标的高精度探测及辐射环境的应用要求,为解决全局与滚动曝光模式兼容难度大、灵敏度和动态低、帧速不高、抗辐照水平低等问题,对CMOS图像传感器架构、像素结构、列并行高精度数字化、高速读出、抗辐照加固等技术进行研究。基于单边列并行DDS、多模兼容的架构方案,设计了一款7.5μm×7.5μm,2048×2048可见光CMOS图像传感器,采用双增益像素结构、高帧速数字化读出、多通道可选输出、像素和电路抗辐照加固等方法,实现了全局与滚动曝光兼容、高灵敏度高动态成像、高精度数字化和高速输出、抗辐照加固等技术验证,填补了国内多模曝光兼容抗辐照CMOS图像传感技术研究空白。测试结果表明:器件功能正常,成像效果良好,动态范围、满阱电荷、灵敏度、帧速、抗辐照等指标满足预期要求,对高速高动态成像及辐射环境的系统应用具有重要意义。

Abstract:

To achieve high-precision detection of high-speed targets and meet the application requirements of radiation environments, a CMOS image sensor architecture, pixel structure, column-parallel high-precision digitization, high-speed readout, and radiation hardening are investigated to solve problems such as compatibility issues between global and rolling exposure modes, low sensitivity and dynamics, low frame rate, and low radiation-resistance levels. Based on a single-sided column-parallel direct digital synthesis (DDS) and multi-mode compatible architecture, a 7.5μm×7.5μm, 2048×2048 visible-light CMOS image sensor is developed. A dual-gain pixel structure, high-frame-rate digital readout, multiple-channel selectable output, and pixel/circuit radiation hardening are adopted to achieve global and rolling exposure compatibility, high-sensitivity and dynamic imaging, high-precision digitization and high-speed output, and radiation hardening. The sensor fills a gap in domestic research on multimode exposure-compatible radiation-resistance contact image sensor (CIS) technology. Test results show that the device functions normally, the imaging output is satisfactory, and the parameters meet the expected requirements. These include the dynamic range, full well capacity, sensitivity, frame rate, and radiation resistance. These results are of great significance for high-speed, high-dynamic imaging, and radiation-environment system applications.