8 Single-Event Transients (SET) Results

The TRF0208-SEP was characterized for SETs from 9.62 to 56.1MeV-cm²/mg (refer to Table 5-1) at +3.3V supply voltages. The device was tested at room temperature for all SETs runs. Since the TRF0208-SEP is a flip chip device, the devices were thinned to 50µm for proper heavy-ion penetration into the active circuits. Flux of 10⁵ and 10⁶ (most used) ions/cm²-s and fluences of 10⁶ and 10⁷ (most used) ions/cm² per run were used during the heavy ion characterization. The devices were tested under dynamic (AC) inputs (as described in Section 6). The SETs discussed on this report were defined as output voltages excursion that exceed a window trigger set on the MSO58B. Outputs of the TRF0208-SEP were converted to SE using HL9402 balun and monitored. Test conditions used during the testing are presented in Table 8-1. Weibull-Fit and cross section for DUT #2 and DUT#3 are presented in Figure 8-1. To calculate the cross section values at different supply voltages the total number of upsets (or transients) and the fluences where combined (add together) by LET_EFF to calculate the upper bound cross section (as discussed in Appendix B) at 95% confidence interval. The σ_PERCASE cross section presented in the summary tables, was calculated using the MTBF method at 95% confidence. For the SET test upsets were observed when setting the trigger to ±20 mV and monitoring the output of the balun. Worst case AC upset for each leg is shown in Figure 8-2. Though not observed during the testing, note that an SET event can result in output going up to saturation voltage.

The upper-bound SET cross-sections (σ_ALL) was calculated using the events and fluences. Using the MTBF method at 95% confidence interval (see Appendix B for a discussion of the MTBF cross section calculation method), the combined upper bound cross section is:

σ_{SET-ALL-AC-DIFF} ≤ 4.5 × 10^–6cm²/device at LET = 57.1MeV-cm²/mg, T = 25°C, 95% conf. and V_DD = +3.3V