10 µF at 2.5 V — low-voltage bulk decoupling in 0805
The TAJR106K002RNJ is a molded tantalum capacitor from the TAJ series, rated 10 µF at 2.5 V with ±10% tolerance. In an 0805 case, it fits standard low-voltage decoupling spots on 1.8 V or 2.5 V logic rails — but the 2.5 V rating leaves only 0.7 V of headroom above a 1.8 V rail, so a 4 V or 6.3 V part is safer if the rail sees any ripple or start-up overshoot.
4.5 Ohm ESR — ripple current and filtering limits
With a 4.5 Ohm ESR, this capacitor is not a low-ESR part. The ripple current rating will be modest — expect to derate it for any switching regulator output where the ripple current exceeds a few hundred mA. It is better suited for bulk storage or decoupling where the AC current component is small, such as on a reset line or a lightly loaded linear regulator output.
The molded case and tantalum construction hold capacitance stable across that span, though ESR rises at low temperature — factor that into cold-start timing circuits.