During the SEL testing the device was heated to 125°C using a PID controlled heat gun (MISTRAL 6 System (120V, 2400W)). The temperature of the die was constantly monitored during testing at TAMU through an IR camera integrated into the control loop to create closed-loop temperature control. The die temperature was verified using a standalone FLIR thermal camera prior to exposure to heavy ions at KSEE.

The species used for the SEL testing was ¹⁰⁹Ag (TAMU) at 15 MeV/nucleon and ¹⁰⁹Ag (KSEE) at 19.5 MeV/nucleon. For both ions an angle of incidence of 0° was used to achieve a LET_EFF of ≈ 48MeV·cm²/mg (for more details refer to Table 5-1). The kinetic energy in the vacuum for ¹⁰⁹Ag (TAMU) is 1.635 GeV and ¹⁰⁹Ag (KSEE) is 2.125GeV. Flux of ≈ 10⁵ ions/cm²/s and a fluence of ≈10⁷ ions/cm² per run was used. Run duration to achieve this fluence was ≈2 minutes. The 4 devices were powered up for SEL at the maximum recommended operating conditions based on the SOA, which are a V_IN of 6.5V and 3A/channel in the "high current case" and a V_IN of 7V and 1.5A/channel in the "high voltage case". Output conditions were tested in two different configurations, either with each channel configured to output 1.2V or each channel configured to output 1.8V. During testing of the 4 devices, the TPS7H4102-SEP did not exhibit any SEL with heavy-ions with LET_EFF = 48 MeV·cm²/mg at flux ≈10⁵ ions/cm²/s, fluence of ≈10⁷ ions/cm², and a die temperature of 125°C, while maintaining operating conditions within the SOA. Table 8-9 shows the SEL test conditions and results. Figure 7-3 shows a plot of the current vs time for run #1.

Using the MFTF method described in Single-Event Effects (SEE) Confidence Interval Calculations application report and combining (or summing) the fluences of the four runs at 125°C (4 × 10⁷), the upper-bound cross-section (using a 95% confidence level) is calculated as:

σ_SEL ≤ 9.22 x 10^-8 cm²/device for LET_EFF = 48 MeV·cm²/mg and T = 125°C.