ESR and ripple — the limit that matters
The TAJP225K020RNJ: The 8.3 Ohm ESR in this 0805 case means the capacitor's self-heating under AC ripple is the limiting factor, not the 20 V DC rating. For a 100 kHz switching ripple of 100 mA RMS, the internal dissipation is about 83 mW — that raises the core temperature above ambient and accelerates ageing. Keep the RMS ripple current below the thermal derating curve for the 125 °C ceiling.
Temperature grade and board fit
The 0805 footprint is a standard two-pad land pattern — no via-in-pad needed, but the solder mask between the anode and cathode pads must clear the 1.35 mm width to avoid tombstoning during reflow.
No direct replacement within the same series — the size code P is fixed by the 0805 case and 2.2 µF / 20 V combination.