15 µF, 6.3 V, 4.1 Ohm ESR — decoupling in an 0805 footprint
The TAJR156M006RNJ is a molded tantalum capacitor from the TAJ series, rated 15 µF at 6.3 V with ±20% tolerance. The 4.1 Ohm ESR at 100 kHz sets the ripple current capability and the self-heating under AC load — for a 15 µF part in an 0805 case, that ESR is typical for the voltage and capacitance combination and directly affects the filtering attenuation in a buck converter output or a power rail decoupling network.
In an avionics power supply or an engine-bay sensor module that sees 105°C ambient, the 125°C ceiling provides margin above the hot-spot temperature of the board. The molded construction with the general-purpose feature set keeps the part suitable for standard reflow assembly without special handling.