The TAJS105M020RNJ is a molded tantalum capacitor from the KYOCERA AVX TAJ series, rated 1 µF at 20 V with ±20% tolerance in a standard 1206 (3216 Metric) surface-mount case. The 20 V rating on a 1206 case gives enough derating headroom for a 12 V rail — typical practice is to derate tantalums by 50% for DC bias, so this part comfortably covers a 10 V bus. With a 12 Ohm ESR, this cap is suited for decoupling, filtering, and timing circuits where moderate series resistance is acceptable — not for high-ripple bulk storage where lower ESR is needed to keep self-heating in check.
The full -55 to 125 °C temperature range means the capacitor is qualified for the same thermal envelope as military-grade ICs and ceramic passives, simplifying derating analysis on a mixed-technology board.