基于FPGA的高精度TDI-CCD信号发生器的设计

由于航天相机所使用的TDI-CCD(Time Delay and Integration Charge Coupled Devices)芯片价格昂贵而且极易损坏,提出了一种利用FPGA(Field Pmgrammable Gate Array)和多通道D/A转换器构成的宽频、高精度TDI-CCD信号发生器的原理方案和实现方法。通过对FPGA器件APA075和D/A转换器件DAC2900的配置,得到频率为11MHz的相关双采样形式的模拟TDI-CCD信号,同时通过改进PCB设计和滤波电路,提高了输出信号的精度,降低了噪声。本设计具有可编程、宽频、高精度和低硬件复杂度等特点,目前已成功应用到新一代高分辨率航天相机数据采集系统的研制中。

A High Accuracy TDI- CCD Signal Generator Based on FPGA

The TDI-CCD chips for space-based camera are very expensive and easy to he damaged. This paper presents the design of a signal generator based on Field Programmable Gate Array(FPGA)and multi-channel D/A device DAC2900.The TDI-CCD signal in the form of correlative double sample (CDS)is generated by using the FPGA device APA075 and D/A device DAC2900 with a frequency of 11 MHz.The signal has high accuracy and low noise owing to the improvement on the PCB and filter circuit. High in accuracy,low in hardware complexity,and wide in frequency range,the programmable system has been successfully applied in the development of data collection system of the new generation high resolution space-based camera.