470 µF, 4 V, 100 mOhm — the ESR is the selection driver
The TPSD477M004H0100: The 100 mOhm ESR at 100 kHz is the parameter that governs ripple current handling and output voltage ripple in a DC-DC converter — a lower ESR means less self-heating and tighter regulation for the same ripple current.
TPS series — low-ESR for bulk decoupling
The TPS series is KYOCERA AVX's low-ESR tantalum line, designed for output filtering on switching regulators where the capacitor's ESR directly sets the output ripple amplitude. At 100 mOhm, this part handles ripple currents that a standard tantalum of the same capacitance and voltage rating would overheat on. Under 4 V DC bias the effective capacitance drops roughly 20-30%, a derating the designer must budget into the loop compensation.