What this 3.3 µF tantalum cap brings to a 20 V rail
The TPSA335M020R2500: A Molded tantalum capacitor from the TPS series, rated 3.3 µF at 20 V with a ±20% tolerance — the 2.5 Ohm ESR sets the ripple current ceiling in a bulk decoupling or RC timing role. The 1206 case (3.20 mm x 1.60 mm footprint, 1.80 mm seated height) is a common size that fits most reflow profiles without tombstoning, though the ESR means it is not the first choice for high-ripple switching regulators — a lower-ESR polymer cap would carry more AC current in that spot.