68 µF, 6.3 V molded tantalum for bulk decoupling
The TAJB686K006YNJ is a 68 µF molded tantalum capacitor from the KYOCERA AVX TAJ series, rated at 6.3 V with ±10% tolerance. The 900 mOhm ESR at 100 kHz defines the ripple current capability — for a 100 kHz buck converter output, the self-heating from ripple current stays within the package rating when the RMS current is kept under the calculated limit from the ESR.
The B-size case measures 3.50 mm x 2.80 mm (1411 / 3528 Metric) with a seated height of 2.10 mm max. This footprint matches standard tantalum B-size land patterns — no pad geometry change from other TAJ B-case parts already on the board.
The TAJ series is a mature, widely second-sourced platform; if this exact order code is tight, functionally equivalent B-case 68 µF, 6.3 V, ±10% tantalum capacitors from other manufacturers exist, but pin-compatibility depends on matching the case code and ESR target.