During SEL characterization, the device was heated using forced hot air, maintaining device temperature at 125°C ± 5°C. A FLIR (FLIR ONE Pro LT) thermal camera was used to validate die temperature to make sure the device was being accurately heated. The species used for SEL testing was a Silver (¹⁰⁹Ag) ion at an energy of 15MeV/µ with an angle-of-incidence of 0° for an LET_EFF of 47.5MeV-cm²/mg. A fluence of approximately 1 × 10⁷ions / cm² were used for the runs.

The three devices were powered up and exposed to the heavy-ions using the maximum recommended supply voltage of 5.5V with a National Instruments PXI Chassis PXIe-4139 and a second National Instruments PXI Chassis PXIe-4139 used for the different voltage levels on the A input pin. The run duration to achieve this fluence was approximately one and a half minutes. As listed in Table 5-3, no SEL events were observed during the six runs, which indicates that the THVD9491-SEP is SEL-free. Figure 5-1, Figure 5-2 show the plot of current versus time for runs one and four, respectively. The R output pin was also monitored during SEL.

Figure 5-1 Current versus Time for Run Number 1 of the THVD9491-SEP at T = 125°C

Figure 5-2 Current versus Time for Run Number 4 of the THVD9491-SEP at T = 125°C

No SEL events were observed, which indicates that the THVD9491-SEP is SEL-immune at LET_EFF = 47.5MeV-cm² / mg and T = 125°C. Using the MFTF method described in Section 5.2, the upper-bound cross-section (using a 95% confidence level) is calculated as: