摘要
A FPGA based time-to-digital converter(TDC)with high precision was designed and realized.A technique that combines coarse time counting and fine time measurement was adopted to achieve a large time measurement range and a fine time resolution.The method of“wave-union”was used in the time interpolation to improve the time resolution.The performance of TDC was tested under lab conditions and the results show that the time resolution of TDC is less than 40 ps.It has been applied for pulse width(time-over-threshold,TOT)measurement.