Radiation characterization of a 28C256 EEPROM

Total-dose, dose-rate, and high-dose-rate memory retention results are presented for the SEEQ 28C256 floating-gate electrically erasable and programmable read-only memory (EEPROM). Total-dose failure levels are mode dependent, i.e., approximately 33 krad(Si) for reading and approximately 9.5 krad(Si) for writing. The write-mode failure level is dose-rate dependent, increasing from approximately 10 krad(Si) at approximately 11 rad(Si)/s to approximately 28 krad(Si) at approximately 0.1 rad(Si)/s. Average upset and latchup thresholds are 3.8*10/sup 8/ rad(Si)/s and 7.7*10/sup 8/ rad(Si)/s, respectively. No latchup windows were observed. Memory contents were retained following exposure up to 108 krad(Si) and following 1*10/sup 12/ rad(Si)/s.>