Exploration of Noise Impact on Integrated Bulk Current Sensors

Current CMOS (Complementary Metal Oxide Semiconductor) technologies show an increasing susceptibility to a rising amount of failure sources. This includes also radiation induced soft errors, which requires countermeasures on several design levels. Hereby, BBICS (Bulk Built-In Current Sensors) represent a promising approach on circuit level. However, it is expected that these circuits, like similar sensors measuring substrate effects, are strongly susceptible to substrate noise. The intention of this work is an in-depth noise analysis of representative bulk sensors based on extracted layout data. Thereby, several aspects are considered, like sensor activation thresholds, impact of the distance to the noise source, and noise generation by test circuits. Results indicate that already noise RMS level of 5 to 9 % of the supply voltage can lead to false detections, which are values in the same order of magnitude of noise generated by test circuits.