47 µF bulk decoupling on a 4 V rail
The TPSA476K004R0500: The 47 µF capacitance at 4 V rated voltage fits bulk decoupling for a 3.3 V or 1.8 V supply rail, where the derating rule of thumb (80 % of rated voltage) leaves 3.2 V working voltage — enough margin for most low-voltage digital cores. 500 mOhm ESR at 100 kHz sets the ripple current rating; for a switching regulator output, this ESR contributes directly to the output ripple voltage and self-heating. A lower-ESR part would reduce ripple but may increase BOM cost.
The 1206 (3216 metric) footprint is a standard size for automated pick-and-place, but the 1.80 mm seated height may conflict with low-profile enclosures under 2 mm clearance.