太阳X射线成像望远镜低噪声信号采集系统

Low Noise Signal Process System for Solar X-ray Imaging Camera

太阳X射线成像望远镜是我国正在研制的第一台观测太阳10nm以下X射线活动的空间仪器,采用背照射式全耗尽型短波敏感CCD作为成像传感器,利用低噪声信号采集系统采集X射线CCD中的电荷信号,生成图像数据。文章在详细介绍X射线CCD输出结构的基础上,分析了CCD输出信号产生的过程,复位噪声产生原因和CCD输出信号的特点,引出了对信号采集系统性能指标和电路结构的要求。继而介绍了信号采集系统的各组成部分,包括前置放大电路,相关双采样电路,主放大器和AD转换电路,重点分析了相关双采样电路的原理,文中给出了各部分的设计参考和测试结果,最后总结了空间相机低噪声信号采集系统的设计原则。测试结果表明该系统成功抑制了噪声,满足太阳X射线观测的要求。

CCD was applied to the under developing Chinese first Solar X-ray imaging telescope as the image sensor, and signal process system was used to process the CCD output signal. The paper described CCD output structure, and analyzed the generation of CCD output signal, the cause of reset noise and CCD signal properties. Those determined performance and circuit of signal process system. It also introduced every parts of signal process system, including the pre-amplifier, correlated double sampling circuit （CDS）, amplifier and the AD converter, especially the CDS methods. Design of each part and the measurement result were presented. Several design principle were discussed at the last. The measurement result shows the signal process system meet the camera requirement.