1 µF at 20 V — decoupling and bulk storage fit
The TPST105K020R2000: This capacitance and voltage combination suits it for power rail decoupling, hold-up storage, or output filtering in DC-DC converter circuits where the rail voltage stays below 20 V. The 2 Ohm ESR (equivalent series resistance) at 100 kHz is the dominant loss term — it sets the ripple current rating and self-heating under AC load. For a 100 kHz switching regulator output, this ESR limits the ripple current to roughly 1 A RMS before the internal temperature rise exceeds the derating curve.
Molded case, wide temperature range
The 1411 (3528 Metric) / 1210 case size is a standard footprint that mates with common PCB land patterns for mid-value tantalum capacitors. Operating from -55°C to 125°C, this capacitor covers the full industrial temperature envelope and the upper end of automotive under-hood ambient. The 20 V rated voltage at 125°C should be derated per the manufacturer's guidelines — typically 50% for tantalum, meaning a maximum applied voltage of 10 V at the high end of the temperature range.