9 ps TDC based on multiple sampling in 0.18 μ m complementary metal-oxide-semiconductor

Abstract

A high-precision measurement method, based on multiple sampling, is proposed for the time interval of two signals inthis study. A time interval measurement circuit integrated into the time-to-digital converter (TDC), is designed based on this highprecision measurement method. In the TDC, the authors use two identical delay lines as the holding module to ensure the twosignals with a constant time interval. The TDC samples the two signals multiple times by a clock signal, whose period is shorterthan that of the delay line. Consequently, the problem of limited resolution caused by a mismatch between delay lines in thedelay-line structure can be avoided, and the precision of the output can be improved. The proposed TDC is designed andsimulated in Semiconductor Manufacturing International Corporation (SMIC) 0.18 μ m complementary metal-oxide-semiconductor process. Simulation results show that the differential non-linearity and the integral non-linearity are always lessthan one least significant bits. The proposed TDC achieves input dynamic range of 0-32.13 ns and time resolution of 9 ps.