220 µF bulk decoupling at 6.3 V — what the ESR means for your rail
The TPSY227K006R0150: For a 100 kHz buck converter output, the 150 mOhm ESR means the capacitor can handle roughly 1.2 A RMS ripple before hitting the power dissipation limit of the 2917 case. The ±10% tolerance on the 220 µF nominal means the actual capacitance at 25°C and 0 V bias ranges from 198 µF to 242 µF. Under DC bias the capacitance drops further — tantalum capacitors lose 20-30% of rated capacitance at the full rated voltage, so the effective capacitance at 6.3 V is closer to 150-175 µF. Budget this derating when sizing the output filter for a regulator loop.
Temperature range and lifetime — the retention reality
The molded epoxy case seals the tantalum anode and manganese dioxide cathode — the leakage current doubles roughly every 10°C above 25°C, so at 125°C the DC leakage is about 32× the 25°C value. For a circuit that sees continuous 125°C, budget the leakage into the supply budget or the capacitor's self-discharge may pull the rail down faster than the regulator can replenish.