The TPSD686K010T0150V: ESR is specified at 150 mOhm at 100 kHz. That figure governs the ripple current capability and the self-heating under AC load — for a 100 kHz switching regulator output, the 150 mOhm ESR keeps the I²R losses low enough that the capacitor runs well within its thermal limit at the rated ripple current. The molded package provides mechanical stability during reflow and the D code size aligns with the industry-common 7343-31 footprint.
This means the capacitor holds its rated capacitance and ESR across the range without derating until the upper limit — useful for outdoor telecom, automotive under-hood (non-engine-bay), and industrial control enclosures where ambient can hit 85°C and the self-heating adds another 20-30°C. The TPS series is a general-purpose tantalum line from KYOCERA AVX, not a low-ESR or high-reliability specialty variant. The 150 mOhm ESR is moderate — suitable for bulk storage and decoupling where the ripple current is modest, but not the first choice for high-ripple POL converters where a polymer or low-ESR tantalum would be specified.