680 µF in a 2917 — bulk decoupling for a 4 V rail
The TAJD687M004RNJ: This TAJ series molded tantalum capacitor delivers 680 µF at a 4 V rating, packaged in the industry-standard 2917 (7343 Metric) case. The ±20% tolerance is typical for tantalum electrolytics; the actual capacitance at the 4 V bias will sit near the nominal value, not at the low end, because tantalum dielectrics lose capacitance with applied voltage.
The TAJ series is a long-running molded tantalum platform from KYOCERA AVX, widely second-sourced by Kemet and Vishay in the same case size and ratings. For a BOM that needs 680 µF on a 4 V rail, this order code is a safe design-in choice without a last-time-buy clock.
Full military temperature span — avionics and downhole ready
In an avionics power supply or a downhole instrument that sees 125°C ambient, the capacitor's leakage current and ESR shift within the datasheet envelope — no need to derate the voltage rating below 4 V unless the application exceeds the manufacturer's derating guidelines (typically 50% at 125°C).