MTBF is the reciprocal of the Fit value.
The Fit value for PowerSoC is 1.3Fit.
Taking the reciprocal, 1/1.3x10^9 = 76923076923 hours = about 87800 years.
Reliability report (please check the latest version)
https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/rr/rr.pdf
(Item in Lifetest Summary)
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Category: power supplies
Tools: -
Devices: Enpirion