What this tantalum does in the circuit
The 4.7 µF capacitance at 16 V covers the typical rail filtering range for 3.3 V and 5 V buses, with enough voltage margin for 12 V rails that see transients. The 800 mOhm ESR is the key loss term: it sets the ripple current the cap can handle before self-heating becomes a reliability concern. For a buck converter switching at 500 kHz, that ESR contributes roughly 10-15 mW of dissipation at 150 mA ripple — well within the part's thermal budget, but worth checking against the converter's ripple current spec.
The molded case and 125 °C rating mean it survives the reflow profile without cracking, which is the failure mode in cheaper tantalums run near their temperature ceiling.
KYOCERA AVX continues to manufacture the TPS series in this B-case package.
B-case size per manufacturer code — 3.50 mm x 2.80 mm footprint, 2.10 mm seated height. The 1411 (3528 Metric) / 1210 equivalent package is a common tantalum footprint; the pad layout matches the standard EIA-535-BAAC outline.