What 150 µF at 4 V means for your rail
The EEF-CX0G151R is a conductive polymer aluminum electrolytic capacitor in the SP-Cap CX series — Panasonic's surface-mount polymer platform, which achieves ESR values an order of magnitude lower than wet electrolytic equivalents of the same cv rating. Rated 150 µF at 4 V with ±20% tolerance, the 4 V ceiling sits below the 6.3 V shelf common in this cv class — it is sized for 3.3 V and lower power rails where the voltage headroom requirement is modest and low ESR is the primary selection driver. ESR is specified at 15 mΩ, and ripple current handling reaches 5.1 A rms at 100 kHz — the frequency at which switching converters dump their fundamental switching noise into the bulk capacitor. That combination makes this part the primary decoupling candidate for compact, battery-powered electronics where a 3.3 V rail sees pulsed load currents.
Thermal and mechanical fit
The 2917 (7343 metric) surface-mount package with its 7.30 × 4.30 mm body and 1.90 mm seated height follows the standard SP-Cap land pattern — the same footprint used across the SP-Cap CX family, so a board spin to a sibling cv rating requires no layout change. Rated for −55 to +105 °C operation and endurance-rated 2000 hours at 105 °C, the upper temperature limit covers most portable and industrial environments — the 105 °C ceiling with the 2000-hour rating tells you this is not a high-temperature industrial-grade part, but it handles the thermal environment inside sealed handheld enclosures.