350 mOhm ESR and the bulk-decoupling decision
The TPSB336K016A0350: The 350 mOhm ESR is the parameter that determines how much ripple current this capacitor can absorb before self-heating becomes a derating issue. For a 100 kHz buck converter output, the ripple voltage across the capacitor is ESR × ripple current — a 350 mOhm ESR at 500 mA ripple produces 175 mV of output ripple, which may be acceptable for a 3.3 V rail but marginal for a 1.2 V core supply. The 33 µF capacitance at 16 V rated voltage gives a 50 % voltage derating margin on a 5 V rail — standard practice for tantalum capacitors to avoid surge failures. The ±10 % tolerance is tight enough for most bulk decoupling; the B case size fits a 1411 (3528 Metric) footprint.
It belongs on avionics power buses, downhole instrumentation, or satellite secondary-side rails where the ambient temperature cycles between cold soak and hot operation.
The TPS series from KYOCERA AVX is a standard molded tantalum line with broad distributor coverage. No stock-holding claim; each lot is quoted per request.