SEU rate prediction and measurement of GaAs SRAMs onboard the CRRES satellite

Upset rate predictions using heavy ion data are shown to overestimate the observed rates on CRRES (Combined Release and Radiation Effects Satellite) for the GaAs C-EJFET (complementary enhancement junctions FET) SRAM (static random-access memory) for both heavy ion and proton upset rates. The predicted heavy ion rates were an order of magnitude high, while the predicted proton upset rates were two orders of magnitude high. Predictions based on heavy ion data for the D-MESFET/resistor technology fell within an order of magnitude of the observed rate for both cosmic ray and proton upset rates. SPICE calculations underpredicted the upset rates for the C-EJFET SRAMs and overestimated the D-MESFET/resistor SRAM upset rates. The underestimate of comsic ray rates may be attributed to either a minimal assumption of collection depth or the possibility of enhanced charge collection. Incorrect use of the circuit-derived critical charge relative to the average measured critical charge would lead to the estimation of the heavy ion upset rate predictions for the D-MESFET/resistor SRAM. Observation of upset rates following onset of the solar flare event suggests that solar protons were responsible for high upset rates at the higher altitudes