470 µF bulk tantalum — D-case, low ESR, wide temperature range
The KYOCERA AVX TPSD477K006R0100 is a molded tantalum chip capacitor in the TPS series, delivering 470 µF capacitance at a 6.3 V rated voltage with ±10% tolerance. The 100 mOhm ESR (Equivalent Series Resistance) directly governs ripple current capability and self-heating in the circuit — lower ESR means the part can handle higher AC ripple without exceeding its internal temperature rise.
ESR and voltage derating — the real selection parameters
The 100 mOhm ESR at 100 kHz typical sets the ripple current rating: for a given ripple current I, the internal power dissipation is I² × ESR. A 2 A ripple dissipates 0.4 W in the capacitor body, which must stay within the package thermal limits at the 125°C upper boundary. Designers targeting high-efficiency DC-DC converters with fast switching edges should verify the ripple current against the capacitor's thermal budget. At 6.3 V rated voltage, standard tantalum derating practice recommends operating at no more than 50-60% of rated voltage for reliability, i.e., 3.15-3.8 V DC bias. This is not a KYOCERA AVX requirement but a well-known application rule for solid tantalum capacitors to prevent field failures due to surge current or reverse bias.