1500 µF at 4 V — what that means at the output rail
The TPSE158M004R0050 is a 1500 µF tantalum capacitor rated at 4 V, built in the TPS series molded case. The 50 mOhm ESR is the spec that governs ripple. At a 500 kHz switching frequency with 2 A ripple current, that ESR contributes 100 mV of ripple voltage at the capacitor terminals — well within the tolerance of most downstream logic, but a higher-ESR part would push the ripple above the 3.3 V rail's allowable droop.
Temperature grade and operating envelope
Rated for -55°C to 125°C, this is a full military-temperature-range tantalum. The capacitance and ESR shift with temperature — expect capacitance to drop about 10-15% at -55°C and ESR to rise, though the TPS series is formulated to keep the ESR curve flatter than standard MnO2 tantalums across the band. Tantalum capacitors are typically derated to 50-60% of rated voltage for reliable operation; at 4 V, a 2.5 V rail is at 62.5% derating, which is within the standard practice for molded MnO2 types.
It remains in the current TPS series catalog and is available through authorized distribution channels. Sourced to order against BOM quantities. Pricing and lead time confirmed at RFQ; no stock-holding claim or immediate-shipment promise. The part is genuine KYOCERA AVX with full lot traceability and manufacturer warranty when sourced through the authorized chain.