Bayesian Network Modeling of Transistor-Level Total Ionizing Dose Effects Impact on Circuit Electrical Response in Space Environment

Bayesian networks are used to evaluate the reliability of a bipolar operational amplifier (op-amp) and subtracter circuit at different orbital conditions. The total ionizing dose (TID) effects of the op-amp and subtracter are investigated by Co60 gamma ray at the Heilongjiang Academy of Sciences, China, and the dose rate is 100 rad(Si)/s. The most sensitive transistors that dominate the degradation of the output voltage range parameter of the op-amp are identified and the interaction between subtracter modules is studied. The extreme-environment radiation effect technology computer aided design (ERETCAD) code is used to calculate the cumulative distributions of TID under different conditions. Finally, the Bayesian networks are established by combining the experimental results and energy spectra to evaluate the failure probability and predict the lifetime of the devices. This method provides a convenient way for on-orbit failure probability evaluation and lifetime prediction of circuits and systems.