0.15 µF, 35 V — the BOM-fit check
The TAJA154K035RNJ is a molded tantalum capacitor from the KYOCERA AVX TAJ series, rated at 0.15 µF capacitance with a 35 V working voltage and ±10% tolerance. This combination fits decoupling, filtering, or timing roles in circuits where a small-value tantalum is specified for its stable capacitance over temperature and voltage bias.
The 1206 (3216 Metric) case size (3.20 mm x 1.60 mm footprint, 1.80 mm seated height) fits standard PCB layouts for this package class.
21 Ohm ESR — what it means for ripple and loss
The 21 Ohm equivalent series resistance is the dominant loss term at ripple frequencies. For a 0.15 µF capacitor at 100 kHz, the capacitive reactance is about 10.6 Ohms, so the ESR adds roughly 2× the impedance — the self-heating from ripple current must be checked against the datasheet ripple current rating to stay within the 125°C limit.