1 µF, 35 V — the BOM fit check
The TAJA105K035TNJ: This is a 1 µF, 35 V tantalum capacitor in the TAJ series from KYOCERA AVX. The ±10% tolerance covers the typical decoupling and filter applications where the exact value needs to stay within a tight window. The 35 V rating gives headroom above a 12 V or 24 V rail — a 24 V bus with 10 % ripple peaks at 26.4 V, well inside the 35 V ceiling.
AEC-Q200 — why it matters for the board
AEC-Q200 qualification means this cap passed automotive-grade stress tests: temperature cycling, moisture resistance, and mechanical shock. For a non-automotive build, the AEC-Q200 rating still buys you a tighter reliability margin — fewer field failures from thermal cycling in outdoor telecom or industrial motor drives.
1206 footprint and ESR — layout reality
The 1206 (3216 Metric) case measures 3.20 mm x 1.60 mm, seated height 1.80 mm max. This is a common land pattern — no special fan-out or via-in-pad needed for reflow. ESR is 7.5 Ohm at 100 kHz. For a 1 µF cap, that ESR is typical for a small-case tantalum — it limits ripple current to about 200 mA RMS at 25 °C. If your rail sees higher ripple, you may need a larger case or a low-ESR polymer cap.