470 µF bulk cap for a 4 V rail — what the ratings mean
TAJD477M004RNJ is a molded tantalum capacitor from KYOCERA AVX's TAJ series, rated 470 µF at 4 V with ±20% tolerance. The 900 mOhm ESR sets the ripple current ceiling: at 470 µF, the self-heating from ripple current will be dominated by that ESR, so check the AC current in your circuit against the datasheet's ripple current derating curve.
It fits avionics black boxes, satellite power supplies, and downhole instrumentation where the ambient can swing from cold soak to hot wellhead. The molded case gives better mechanical stability than conformal-coated parts in high-vibration environments.
Listed as Active — no end-of-life notice, no last-time-buy clock. The part is still in KYOCERA AVX's current catalog, so production orders can be placed without a sunset window.