The TAJA226K006RNJV: This is a 22 µF molded tantalum capacitor rated at 6.3 V DC, ±10% tolerance, from the TAJ series by KYOCERA AVX. The 3 Ohm ESR at 100 kHz sets the ripple current ceiling — for a 100 kHz buck output, the self-heating from ripple current stays within the 2000-hour lifetime at 125°C only if the RMS current is kept below ~140 mA.
The 2000-hour endurance at 125°C is the standard tantalum derating floor; for continuous 125°C operation, derating the applied voltage to 50% of rated (3.15 V) is common practice to stay inside the safe operating area.
1206 (3216 Metric) case, size code A — 3.20 mm x 1.60 mm footprint, 1.80 mm seated height. The molded body is polarity-sensitive; the anode band marks the positive terminal. Surface-mount assembly: standard 1206 land pattern applies. The molded case is compatible with reflow soldering; no special bake-out required for moisture-sensitive level (MSL) if the part is used within the floor-life window.