Radiation Assessment of a 15.6ps Single-Shot Time-to-Digital Converter in Terms of TID

Abstract

This article presents a radiation tolerant single-shot time-to-digital converter (TDC) with a resolution of 15.6 ps, fabricated in a 65 nm complementary metal oxide semiconductor (CMOS) technology. The TDC is based on a multipath pseudo differential ring oscillator with reduced phase delay, without the need for calibration or interpolation. The ring oscillator is placed inside a Phase Locked Loop (PLL) to compensate for Process, Voltage and Temperature (PVT) variations- and variations due to ionizing radiation. Measurements to evaluate the performance of the TDC in terms of the total ionizing dose (TID) were done. Two different samples were irradiated up to a dose of 2.2 MGy SiO 2 while still maintaining a resolution of 15.6 ps. The TDC has a differential non-linearity (DNL) and integral non-linearity (INL) of 0.22 LSB rms and 0.34 LSB rms respectively.