基于FPGA＋DSP的核信号数字时间谱仪设计

Development of a Digital Time Spectrometer Based on FPGA+DSP for Nuclear Physics Experiment

针对核电子学中核脉冲信号的高速实时数字化处理,设计了基于FPGA+DSP的两通道核信号数字时间谱仪。该实验平台基于数字恒比定时(dCFD)原理,采用高速运放和ADC进行模拟信号成型采样,数字信号送入FPGA完成波形判选、数据缓冲、FIR滤波和基线恢复,利用DSP实时信号重构和函数定时,通过USB2.0接口与上位机通信。该系统的主要特点是具有模数电路的高度集成、数字信号的实时运算,接近模拟定时的精度。

The development of a Fast Digital Real-Time spectrometer for Timing of Nuclear Pulse Signals is discussed.The double-channel signal processing platform is based on FPGA＋DSP with digital Constant Fraction Discriminate algorithm.Each channel features a 14-bit 125 MHz Samples/s ADC for signals sampling.FPGA controlls the whole system and implements on-chip Pulse trigger,Data buffer,FIR Filter,Baseline recovery.DSP implements on-line spectrum analysis and communication with computer by USB 2.0 interface.The main characteristics of the system is highly integrated circuit,digital real-time computing,precision close to analog circuit.