Radiation-Tolerant All-Digital PLL/CDR with Varactorless LC DCO in 65 nm CMOS

This paper presents the first fully integrated radiation-tolerant All-Digital Phase-Locked Loop (PLL) and Clock and Data Recovery (CDR) circuit for wireline communication applications. Several radiation hardening techniques are proposed to achieve state-of-the-art immunity to Single-Event Effects (SEEs) up to 62.52/mg as well as tolerance to the Total Ionizing Dose (TID) exceeding 1.5Grad. The LC Digitally Controlled Oscillator (DCO) is implemented without MOS varactors, avoiding the use of a highly SEE sensitive circuit element. The circuit is designed to operate at reference clock frequencies from 40–320 or at data rates from 40Mbps–320Mbps and displays a jitter performance of 520 with a power dissipation of only 11 and an FOM of −235 .