Bulk decoupling in tight thermal environments
The TPMD477M006R0030 is a molded tantalum capacitor from the KYOCERA AVX TPM series, rated 470 µF at 6.3 V with a low 30 mOhm ESR. The 30 mOhm ESR keeps ripple heating under control — for a 1 A ripple current, dissipation is just 30 mW, well within the part's thermal budget even at 125°C ambient. The 2917 (7343 Metric) surface-mount package, size code D, sits on a standard 7.30 x 4.30 mm footprint.
ESR and ripple current — what the 30 mOhm buys
Equivalent series resistance of 30 mOhm is low for a 470 µF tantalum at 6.3 V. That ESR directly sets the ripple current rating and the output voltage ripple in a DC-DC converter. A 500 kHz buck switching 2 A sees roughly 15 mV of ripple across the capacitor alone — the ESR term dominates over the capacitive term at that frequency. The ±20% tolerance on the 470 µF nominal capacitance is standard for tantalum electrolytics. The actual capacitance varies with temperature and DC bias — at 125°C and rated voltage, expect the value to drift within the tolerance band. For a filter pole or timing circuit, account for the full spread at the temperature extremes.