基于FPGA的时间-数字转换电路设计

Design of Time Digital Converter Based on FPGA

采用VHDL语言,设计了一种基于现场可编程逻辑阵列FPGA的TDC(Time Digital Converter)时间-数字转换电路,对时间-数字转换电路的方法进行了研究,目的在于研究一种可以在航天器导航系统中利用脉冲星X射线光子脉冲的方案。为了解决在时间测量上难以同时获得大动态与高分辨率的难题,本文基于FPGA芯片对时间内插法进行了改进,采用粗时间测量与细时间测量相结合的方法,提出了基于延时单元的TDC方法。

Based on VHDL,a circuit was designed to realize Time Digital Converter（TDC）. A method was proposed to measure photon pulse＇s arrival time in detector navigation system. As methods available can hardly realize a high resolution,this method of TDC is based on Field Programmable Gate Array（ FPGA） chip and studied by improving time interpolating,and combining high-resolution time measurement with low-resolution time measurement. The TDC circuit has a lot of advantages,such as high-resolution,large-dynamic-range,simple-structure. TDC circuit which is an important part of the pulsar X-ray photon pulse＇s arrival time digital converter circuit and data acquisition system was designed with VHDL on Virtex II Pro chip.