A Study of SEU and TID Effects in 25-GHz LC -VCOs in 22-nm FinFET

Voltage-controlled oscillators (VCOs) are a fundamental building block in all frequency synthesis circuits and have a heavy influence on the overall system’s electrical performance. Moreover, when operating in a radiation environment, VCOs have been identified as a dominant source of sensitivity to both single-event upsets (SEUs) and total ionizing dose (TID). Hence, in this work, we present the design and analysis of three LC-VCO topologies in a 22-nm FinFET process with variations in the varactor and LC-tail filter to study circuit-level techniques for implementing high-performance VCOs that are robust to SEU and TID. The three VCOs are integrated on a single die and operate over a 43.9% tuning range from 16 to 25 GHz with a peak FoMT of 187.38 dBc/Hz. Heavy ion SEU testing was performed at the Texas A&M Cyclotron Institute up to a linear energy transfer (LET) of 70 MeV $\cdot $ cm2/mg with a $5.6\times $ reduction in SEU cross section achieved when using the rad-hard varactor configuration and a further $2\times $ reduction in cross section achieved when using an LC-tail filter. The VCOs were also tested for TID effects at the Texas A&M TRIGA reactor to evaluate the frequency and phase noise (PN) degradation up to a total dose of 300 krad(Si).