SLVK117 October 2022 TPS7H2221-SEP
During SEL characterization, the device was heated using Closed Loop PID controlled heater (MISTRAL-6 SYSTEM 120V 2400W), maintaining the DUT temperature at 125°C. The die temperature was verified using a IR-camera (see Figure 3-3).
The species used for the SEL testing was Xenon (129Xe) and Silver (109Ag) with an angle-of-incidence of 0° for an LETEFF = 42.7 and 46.8 MeV·cm2/mg (for more details refer to Section 5). The kinetic energy in the vacuum for 129Xe is 3.197 GeV (25-MeV/amu line) and for 109Ag is 1.634 GeV (15-MeV/nucleon line). Flux of approximately 105 ions/cm2·s and a fluence of approximately 107 ions/cm2 were used for the five runs. Run duration to achieve this fluence was approximately 2 minutes. The five devices were powered up and exposed to the heavy-ions using the maximum recommended voltage of 5.5-V and loaded to 1.25-A using a 4.4-Ω power resistor or the Chroma E-Load in constant resistance (CR) mode at the same resistance value.
No SEL events were observed during all five runs, indicating that the TPS7H2221-SEP is SEL-free. Table 7-1 shows the SEL test conditions and results. Figure 7-1 shows a plot of the current vs time for run # 1.
RUN # | UNIT # |
Load Type |
ION | LETEFF (MeV·cm2/mg) |
FLUX (ions·cm2/mg) |
FLUENCE (# ions) |
SEL Event Occured? |
---|---|---|---|---|---|---|---|
1 | 1 |
Discrete Power Resistor |
129Xe | 42.7 | 1.07 × 105 | 9.99 × 106 |
No |
2 | 2 |
Discrete Power Resistor |
129Xe | 42.7 | 1.17 × 105 | 9.96 × 106 |
No |
3 |
3 |
Chroma (Constant Resistance) |
129Xe | 42.7 | 9.77 × 104 | 1 × 107 |
No |
4 |
4 |
Chroma (Constant Resistance) |
109Ag |
46.8 |
1.15 x 105 |
1 × 107 |
No |
5 |
5 |
Chroma (Constant Resistance) | 109Ag |
46.8 |
1.10 x 105 | 1 × 107 |
No |
Using the MFTF method described in Single-Event Effects (SEE) Confidence Interval Calculations application report and combining (or summing) the fluences for the three runs at 129Xe, VIN = 5.5 V @ 125°C (3 × 107), and the two runs at 109Ag, VIN = 5.5 V @ 125°C (2 × 107), the upper-bound cross sections (using a 95% confidence level) are calculated as:
σSEL ≤ 1.197 × 10–7 cm2/device for LETEFF = 42.7 MeV·cm2/mg and T = 125°C.
σSEL ≤ 1.844 × 10–7 cm2/device for LETEFF = 46.8 MeV·cm2/mg and T = 125°C.