100 µF in a 1206 footprint — dense capacitance for a 4 V rail
This TAJA107K004SNJ packs 100 µF into a 1206 (3216 Metric) molded case — roughly 3.2 mm × 1.6 mm board space. At 4 V rated, it fits low-voltage supply decoupling or output bulk storage where board area is tight.
2000-hour endurance at 125°C — hot-environment fit
Rated 2000 hours at 125°C — this is the lifetime ceiling. In an engine-bay ECU or a base-station power module that sees sustained 105°C ambient, the cap's internal temperature will be lower, extending service life beyond the datasheet minimum. That qualifies it for avionics, downhole tools, and outdoor telecom gear where the board cycles from cold soak to hot run.
ESR at 100 kHz — what the 1.4 Ohm means in circuit
ESR is 1.4 Ohm at 100 kHz — typical for a size-A tantalum at this capacitance. For a 100 µF cap on a 4 V rail switching at 500 kHz, the ripple current through that ESR generates I²R heating; budget the thermal rise against the 125°C limit.
KYOCERA AVX continues to manufacture the TAJ series.