What the 2.8 Ohm ESR means for your power rail
The TAJB685K025RNJ: The 2.8 Ohm ESR on this 6.8 µF tantalum sets the ripple current ceiling — at 100 kHz, the capacitor dissipates I²R heat that raises the internal temperature. For a 25 V rail with 100 mA ripple, the self-heating stays under 30 mW, but a higher-ripple supply (e.g., a buck converter output) needs a parallel low-ESR ceramic to share the AC current.
The molded construction provides mechanical stability across the range.
1411 (3528 Metric) case, size code B, measures 3.50 mm x 2.80 mm with a seated height of 2.10 mm max. Surface-mount — the standard 1210 footprint fits the 3528 land pattern without adjustment.