Automotive-grade molded tantalum for under-hood decoupling
The TAJB686K006TNJ is a molded tantalum capacitor from the KYOCERA AVX TAJ series, rated 68 µF at 6.3 V with ±10% tolerance. The 2000-hour endurance at 125°C is the standard automotive-grade lifetime test for molded tantalum chips; in practice, the capacitor will survive much longer at lower temperatures, but the 125°C rating is the ceiling for continuous operation in a hot environment.
ESR and ripple current — what 900 mOhm buys you
With an ESR of 900 mOhm at 100 kHz, this part is best suited for bulk decoupling on 3.3 V or 1.8 V rails where the ripple frequency is below a few hundred kilohertz — think input/output filtering for linear regulators or low-frequency DC-DC converters. At higher switching frequencies (above 1 MHz), the ESR will dominate the impedance, so a lower-ESR ceramic or polymer cap would be a better choice for the high-frequency bypass slot.
Package and footprint — 1411 (3528 Metric) B-size
The case is the standard 1411 (3528 Metric) size, manufacturer code B, measuring 3.50 mm x 2.80 mm with a seated height of 2.10 mm max. The footprint is the same as other B-size tantalum caps from the TAJ series, so a single PCB pad pattern covers the whole family — useful if you need to swap capacitance values without a board spin.