在火星矿物光谱分析仪中采用模拟4像元合并,可以使仪器应对深空探测中的复杂环境,从而达到高信噪比与高动态范围的要求。提出了一种新型CDD片上2×2像元合并的驱动方法,并验证了其输出的合理性。针对e2v CCD 47-20芯片,研究了CCD结构并设计了行方向与列方向2像元合并的方法,使之可以通过FPGA控制生成驱动波形。基于CCD片上放大器的结构,通过仿真其行方向两元输出模拟信号模型,得到了四阶梯模型。均匀光照射实验结果表明,得到的4-binning模式下CCD输出信号与仿真结果一致,验证了理论的正确性。其输出电压在600 mV以下范围内表现出了良好的线性变化趋势,证明该方案的合并结果是精确可靠的。

The use of analog 4-binning mode in Mars mineral spectrum analyzers enables the instruments to deal with the complex environment in deep space and hence to meet the requirements of high signal-to-noise ratio and large dynamic range. A new on-chip 2×2 pixel binning driving method is proposed and the rationality of its output is verified. For an e2v CCD 47-20 chip, the CCD structure is studied and the 2-binning methods both in horizontal direction and in vertical direction are designed so that the driving wave can be controlled by FPGA. On the basis of the structure of a CCD on-chip amplifier, a four-stage model is obtained by simulating the 2×1-horizontal output analog signal model. The result obtained in the uniform light illumination experiment shows that the CCD output signal in the 4-binning mode is the same as the simulation result. This confirms the CCD amplification theory. The output voltage presents a linear trend when the value is than 600 mV, which proves that the combined results of the scheme are accurate and reliable.