高速高精度数据获取系统的研究与应用

Research and application of the high speed and high precision data acquisition system

设计1个高速高精度的适用于光伏型红外探测器的数据获取系统。该系统可以同时采集6路随机的入射红外辐射的能量,并计算入射红外辐射的谱线。采用了Xilinx公司的Spartan 3系列的FPGA作为控制核心,实现了对输入信号的采样跟踪和峰值保持、AD变换、AD变换数据预处理、数据存储、数据上传,并协调各部分的工作。系统的输出数据经USB口上传至PC,然后在PC上进行数据分析处理和谱线显示。FPGA复杂的控制逻辑采用嵌套的状态机实现。实验结果表明,采集死时间大约为6~7μs,误差小于1 mV。

A six channel high speed and high precision data acquisition system for the photovoltaic infrared detector was designed.The system could acquire the energy of six channel randomly incident infrared radiation simultaneously,and calculate the energy spectrums of the incident radiation.A Spartan3 series FPGA chip of the Xilinx Inc.was used as the controlling core.FPGA controlled the sampling,tracking and holding of the input signal,AD conversion,the preprocessing of the AD converted data,data storing,data buffering and data uploading,and coordinated the work of different modules in the system.The output data of the system was then uploaded to the PC via USB port,and processed in the PC.Finally,the energy spectrums of the incident radiation were displayed.The complicated logic design of FPGA was implemented using nested state machine.The final experimental result showed that data acquisition deadtime is about six to seven microsecond,the error is less the 1 microvolt.