TFW your optical data link passed radiation test perfectly,... | niconiconi

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TFW your optical data link passed radiation test perfectly, only 5 bit errors under enormous radiation for days - then after the test, someone power cycled it - it's now completely dead because the Boot ROM or fuse has gone bad... #electronics

LANSCE neutrons, X-ray to FOCI engine (SMU)
− BER test at LANSCE
* Neutrons at LANSCE
flux: 2.9 × 10 5 n/cm2s
total fluence 3.8×10 10 n/cm 2 (1.5 days)
* Stratix II FPGA 5 Gbps
* TX: no SEU, SEFI during test
* RX: 11 SEU (1bit), no SEFI
Error cross section:
2.7×10 11 /cm 2 (0 error)
2.9×10 10 /cm 2 (11 error)

-> Power cycle, IC initialization FAILED!

− BER at SMU, X-ray
* 160 kV x-ray flux 167 Gy/hr
after 3.84 kGy (23 hr) -> 14 bit errors
* Increase flux to 4.46 kGr/hr
total 210 kGy (47 hr) -> 5 bit errors
-> Power cycle, IC initialization FAILED!

DC converter checked, okay!

Could be the OTP?
non-volatile memory fragile to radiation induced charge

Like 1 3 Nov 2021 at 19:17 | Open on cybre.space

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