What the 2.8 Ohm ESR means for your power rail
The TAJB156K010A: The 2.8 Ohm ESR at 10 V and 15 µF sets the ripple-current ceiling — for a 100 kHz switching regulator, the capacitor self-heats from the ripple current squared times ESR. A 200 mA ripple current dissipates 114 mW, which at 85°C ambient leaves about 40°C margin before hitting the 125°C limit. If your rail sees higher ripple, parallel two parts to halve the effective ESR.
At -55°C the ESR can increase by 2-3×, which matters for a timing circuit or a cold-start power supply in an outdoor base station or avionics box.
Package and board fit — 1411 (3528 metric) B case
The B case size (3.50 mm × 2.80 mm, seated height 2.10 mm) is a common tantalum footprint shared across multiple manufacturers. The 1411 / 3528 metric pad layout is standard — no special fan-out or via-in-pad needed. The molded body is compatible with reflow soldering; moisture sensitivity level is typically MSL 1 (no bake required before reflow) for the TAJ series, but verify the reel label for the specific date code.