Why the 1.8 Ohm ESR matters for this 6.8 µF tantalum
The TPSA685M006R1800: The 1.8 Ohm ESR on this 6.8 µF molded tantalum sets the ripple current ceiling and the AC loss budget. A ceramic MLCC of the same capacitance would have an ESR below 10 mOhm, but it would also lose 80% of its capacitance under DC bias — this tantalum holds its value across the full 6.3 V rated voltage. If you are replacing a ceramic with this part, the higher ESR means the self-heating under ripple is real; check the ripple current derating against the ambient temperature.
Temperature range and board placement
It can sit next to a hot MOSFET on a motor drive or inside a sealed outdoor telecom enclosure without a capacitance roll-off curve — the solid electrolyte construction keeps the dielectric constant stable across the band. The 1206 case is a standard footprint; the 1.80 mm seated height fits under a 2 mm board-to-board clearance.
The TPS series is a standard catalog line from KYOCERA AVX.