Testing a Fault Tolerant Mixed-Signal Design Under TID and Heavy Ions

Abstract

© 2021, Brazilian Microelectronics Society. All rights reserved.— This work presents results of three distinct radiation tests performed upon a fault tolerant data acquisition system comprising a design diversity redundancy technique. The first and second experiments are Total Ionizing Dose (TID) essays, comprising gamma and X-ray irradiations. The last experiment considers single event effects, in which two heavy ion irradiation campaigns are carried out. The case study system comprises three analog-to-digital converters and two software-based vot-ers, besides additional software and hardware resources used for controlling, monitoring and memory manage-ment. The applied Diversity Triple Modular Redundancy (DTMR) technique, comprises different levels of diversity (temporal and architectural). The circuit was designed in a programmable System-on-Chip (PSoC), fabricated in a 130nm CMOS technology process. Results show that the technique may increase the lifetime of the system under TID if comparing with a non-redundant implementation. Considering the heavy ions experiments the system was proved effective to tolerate 100% of the observed errors originated in the converters, while errors in the processing unit present a higher criticality. Critical errors occur-ring in one of the voters were also observed. A second heavy ion campaign was then carried out to investigate the voters reliability, comparing the the dynamic cross section of three different software-based voter schemes im-plemented in the considered PSoC.