Polymer bulk — 220 µF at 2.5 V in the 2917 SMT footprint
The EEF-CX0E221R is a Panasonic SP-Cap CX polymer capacitor in the 2917 (7343 metric) surface-mount package, rated 220 µF at 2.5 V with ±20% tolerance. The polymer electrolyte gives it a significantly lower ESR than a comparable electrolytic — 15 mΩ typ — which is the key selection driver for decoupling and bulk-rail applications where ripple current handling matters more than raw capacitance density.
ESR and ripple — the polymer advantage at 100 kHz
15 mΩ ESR with 5.1 A ripple current capability at 100 kHz means this part handles the high-frequency switching transients in point-of-load converters without the thermal runaway risk a higher-ESR part carries at equivalent RMS current. The polymer electrolyte does not dry out the way an electrolytic's liquid electrolyte does, which is why the 2000-hour lifetime rating at 105 °C is a realistic field figure, not an extrapolated number.
Temperature grade and board footprint
The -55 °C to 105 °C operating window covers the full industrial temperature band — this is the rating to check against an enclosed DC-DC module where ambient at the cap can hit 85 °C+ during load transients.
Sourcing posture — active, single-source, quoted to order
Panasonic's SP-Cap CX family is a long-run product line, but the 2.5 V rating is specific to this voltage bin — a different rated voltage in the same 2917 package is not automatically a drop-in at the BOM line without confirming the voltage headroom in your rail. Sourced to order through independent distribution with availability and pricing confirmed at RFQ.