High precision time measurement using a self-timed ring oscillator based TDC

A new high resolution time-to-digital converter (TDC) based on a self-timed ring (STR) oscillator is presented. Thanks to the STR unique features, the time resolution of the proposed TDC can be tuned as fine as needed. In addition, on-the-fly time measurements can be carried out on fast non-periodic signals. To provide a proof of concept of this new technique, a design of a 5-stage STR-based TDC has been implemented and simulated using a 28 nm FDSOI CMOS technology.