0.68 µF at 25 V in an 0805 — where it fits
The TAJR684K025RNJ: This is a molded tantalum capacitor from the TAJ series, rated 0.68 µF with ±10% tolerance at 25 V. The 0805 case keeps it small — 2.05 mm x 1.30 mm footprint — so it fits tight PCB layouts where a ceramic cap's DC bias derating would eat the effective capacitance. The 13 Ohm ESR is higher than a multilayer ceramic of the same value; that means more self-heating under ripple current, so it is better suited for bulk decoupling or timing circuits than for high-frequency bypass on a switching regulator output.
Rated -55°C to 125°C — full military-temperature span. That puts it in avionics, downhole instrumentation, satellite payloads, or outdoor telecom cabinets where the ambient swings wide. No derating worry at the cold end; at 125°C the leakage current rises, but the cap is specified to operate there.
Lifecycle and how to source
Active product status from KYOCERA AVX — no EOL notice, no NRND flag. The TAJ series is a long-running molded tantalum line, so this order code is safe for new designs and repeat BOM positions.