4.7 µF at 50 V — the derating decision
The TPSD475M050R0300: The -55°C to 125°C operating range covers industrial and automotive ambient conditions, though the capacitance tolerance is ±20% — tighter than the ±20%/+50% some general-purpose tantalums carry, which helps when the downstream regulator expects a known minimum capacitance at cold start.
2917 footprint — board-fit note
The D-size code matches the common EIA 7343-31 body. No special pad geometry beyond the usual 0.50 mm to 0.75 mm overhang per side; the ESR is low enough that the thermal pad area is not current-limiting for most designs.