ESR floor and ripple-current fit
The TPSC336K020P0300: 300 mOhm ESR at 100 kHz is the spec that decides whether this cap survives in a 500 mA buck converter output — the ripple current squared times ESR sets the internal temperature rise, and at 33 µF the self-heating stays under 10 °C for ripple currents up to 1.2 A RMS. Molded construction keeps the ESR stable across the -55 to 125 °C range — the MnO₂ cathode does not dry out, so the capacitance and ESR shift less than 15 % from the 25 °C value at the temperature extremes.
Voltage derating and rail selection
20 V rated voltage on a 33 µF tantalum gives a 60 % derating factor on a 12 V rail — the cap sees 12 VDC, well below the 2/3 derating rule that MnO₂ tantalums need to avoid field failures from surge current. The C case size (6.00 mm × 3.20 mm × 2.80 mm) fits a standard 2312 footprint — the land pattern matches the IPC-7351 C case recommendation, so the layout engineer drops it into an existing decoupling bank without a pad spin.