4 Total Ionizing Dose Characterization Test Results

Total Ionizing Dose Summary Results

The TMS570LC4357-SEP passed post electrical test over the following conditions.

• LDR (0.01rad(Si) / s) unbiased: Post 20krad(Si), 30krad(Si)
• HDR (188 rad(Si) / s) biased: Post 10krad(Si), 20krad(Si), 30krad(Si)

There were no functional or parametric failures at any read point up to 30krad(Si). All data sheet parameters passed up to this exposure level.

The measurements taken post-irradiation for each sample set showed a minimal shift for most parameters at each dose level for both biased and unbiased units. A few parameters (specifically, the ADC current measurements, and flash memory program and erase cycle measurements) did show a greater degree of change between pre- and post-irradiation that were still within the electrical specifications up to 30krad(Si), but marginal to spec at 40krad(Si). All units up to 30krad(Si) dose successfully program and erase immediately after radiation exposure. Noticeable flash pump voltage attenuation occurs with higher dosage, which resulted in increased cycles to complete the erase. Repeat measurements on the 30krad(Si) units show that these parameters recover to near baseline values within hours of the radiation exposure (read points at 45 minutes, two hours, and 72 hours after irradiation. Units were kept under biased conditions between read-points). At 40krad(Si) dose, several of the units failed to erase 45 minutes after irradiation; these units recovered after 72 hours.

Please see Appendix A for HDR report on ADC parameter drift across dosage.

Please see Appendix B for HDR report on flash memory parameter drift across dosage.