Analysis of Single Event Effects in Clock and Data Recovery Circuits based on an LC Voltage Controlled Oscillator

The LC Voltage Controlled Osculator (VCO)-based clock and data recovery (CDR) circuit has been widely utilized in high-speed applications. While significant research has advanced the understanding of single event effects (SEEs) in LC VCOs, this study provides further experimental investigation into their radiation sensitivity. The sensitivity of an LC VCO-based CDR circuit to SEEs was evaluated through heavy ion irradiation and laser testing. Results indicate that the analog modules exhibit greater sensitivity than digital modules, with the analog latch circuits in the frequency divider being the most susceptible. The primary sensitive nodes were identified as the root node of the current mirror and the storage node of the latch. Simulations using a double-exponential current source confirm these experimental results and clarify the failure mechanisms of the sensitive nodes. It is recommended that radiation hardening efforts focus on the analog module to improve the overall stability and reliability of CDR circuits.