针对天文、医学等领域科学成像需要, 设计了一套基于FPGA的科学级CCD成像系统, 并给出了设计中关键技术的解决方法。首先, FPGA提供CCD正常工作所需要的时序信号, 驱动CCD输出模拟图像; 再将模拟信号预放大、相关双采样、AD转化后输出给FPGA进行处理; 最后, 将图像信号在FPGA内部进行格式重组、添加图像信息等操作后输出给存储与显示单元。实验结果表明, 获取的图像质量较好, 不制冷时读出噪声仅6个电子, 满足了科学成像的需要。整个系统性能稳定可靠、实时性强, 具有较好的通用性。

In order to meet the imaging needs in astronomy, medicine and other scientific fields, an improved FPGA-based scientific grade CCD imaging system was designed, and the solutions for some key problems were given. Firstly, FPGA provides the timing signals to drive the CCD to output analog image. Then, pre-amplification, CDS, AD and other circuits are used to process the analog image. Finally, the image was input into FPGA to reshape and add image information to storage and display. Experimental results show, the obtained image quality is good and the readout noise of the system is only 6e-without cooling circuit, which can meet the needs of scientific imaging.