Single Event Upset Sensitivity of Low Power Schottky Devices

Devices built with low power Schottky (LS) technology have become recent popular candidates for earth satellites or interplanetary vehicles (Project Galileo, Jupiter Probe). Accordingly the questions of how such devices respond to the trapped protons of the Van Allen belts and cosmic ray heavy ions (such as the iron group) is of great interest. One study by Woods et al, showed that MSI logic families containing flip-flops fabricated with LS technology are significantly more susceptible to single event upset (SEU) than equivalent standard Schottky devices and low power and standard TTL devices. The work presented here includes data taken from two tests at the U.C. Berkeley 88" cyclotron using heavy ions, one test at the Harvard cyclotron with 130 MeV protons, and one test at the U.C. Davis cyclotron with 56 MeV protrons. From these data and from data taken on the linear energy transfer (LET) threshold at the Cal Tech Van de Graaff, one can estimate SEU rates in systems fabricated with LS technology.