4.7 µF, 10 V, 4 Ohm ESR — what it does on the rail
The TAJB475K010H: This is a molded tantalum capacitor from the TAJ series, rated 4.7 µF at 10 V with a ±10% tolerance and a 4 Ohm equivalent series resistance (ESR). The 4 Ohm ESR places it in the general-purpose filtering range — suitable for bulk decoupling on a 10 V rail or output smoothing in a low-frequency DC-DC converter where the ripple current is modest. It is not intended for high-speed bypass or low-ESR switching regulator inputs; those applications call for a polymer or low-ESR tantalum with ESR below 100 mOhm.
The molded case handles the thermal cycling without cracking, but the 4 Ohm ESR means derating for ripple current at high temperature — the self-heating from ripple adds to the ambient, and the maximum core temperature is 125°C.