0.68 µF, 20 V, 1206 — decoupling and timing fit
The TAJS684K020RNJ is a 0.68 µF molded tantalum capacitor rated at 20 V in the 1206 (3216 Metric) footprint. The ±10% tolerance keeps the timing or filtering corner within a narrow window across the reel. The 25 ohm ESR is typical for this size and voltage class — it limits ripple current handling, so this part is better suited for DC-blocking, timing, or low-ripple decoupling than for high-ripple bulk storage.
A 12 V rail with a 5 V drop margin still leaves 15 V headroom at 125°C.