During SEL characterization, the device was heated using forced hot air, maintaining IC temperature at 125°C. A FLIR (FLIR ONE Pro LT) thermal camera was used to validate die temperature to ensure the device was being accurately heated (see Figure 3-5). The species used for SEL testing was a Xenon (¹²⁹Xe) ion at a linac energy of 25 MeV / µ with an angle-of-incidence of 0° for an LET_EFF of 43 MeV-cm² / mg. A fluence of approximately 1 × 10⁷ ions / 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 5.5-V using a National Instruments PXI Chassis PXIe-1085 and a 5-V, 1 MHz square wave input using a Tektronix AFG3102 function generator. The run duration to achieve this fluence was approximately two minutes. As listed in Table 5-1, no SEL events were observed during the nine runs, which indicates that the SN54SC4T08-SEP is SEL-free. Figure 5-1, Figure 5-2, and Figure 5-3 show the plot of current versus time for run numbers 1, 4, and 7, respectively.

Figure 5-1 Current versus Time for Run 1 of the SN54SC4T08-SEP at T = 125°C

Figure 5-2 Current versus Time for Run 4 of the SN54SC4T08-SEP at T = 125°C

Figure 5-3 Current versus Time for Run 7 of the SN54SC4T08-SEP at T = 125°C

Using the MFTF method described in Single-Event Effects (SEE) Confidence Internal Calculations application report, the upper-bound cross section (using a 95% confidence level) is calculated as: