A 8bit, 2.5 ps Resoultion Time-to-Digital Converter in 130nm SiGe Technology

In this paper, a 8hit, 2.5ps two-step time-to-digital converter is implemented in 130 nm SiGe technology, with a matching coarse-fine gating circuit to reduce transmission error. A low-precision delay chain quantization architecture is used for the coarse stage to achieve wide dynamic range. And a high-precision structure based on time amplifier and unit time comparator is used for the fine stage to ensure higher resolution. Compared with traditional Vernier and exponential structure, this structure balances inter stage matching and linearity. The simulation results show that the time-to-digital converter can balance the performance of resolution, linearity and dynamic range. DNL and INL are, respectively, 0.86 LSB and 1.019 LSB. It can be used as a phase detector with digital output.