Worst case operating frequency determination of CMOS digital VLSI circuits operating in radiation environments

There are in existence a number of CAD tools that perform circuit simulations and analyze circuit performance before fabrication. Most of these simulators do not take long-term environmental effects into account. These environmental effects on VLSI circuits are specifically more important for performance estimation in hostile environments such as high temperature and space radiation environments. The ICs designed for normal environments fail to function normally in these hostile environments. A study is made of the effects of one such environment, the space-radiation environment, on CMOS digital circuits, and methods for extending the operational life of a part by changing operating parameters, namely, operating frequency, are proposed. Although the study specifically concentrates on the space environment, the concept can be applied to any hostile environment