Sizing a 100 µF bulk cap for 25 V rails
This TAJE107M025SNJ is a molded tantalum capacitor from the TAJ series, rated 100 µF at 25 V with ±20% tolerance and 300 mOhm ESR at 100 kHz. The 25 V rating gives headroom on a 12 V or 5 V rail, but on a 24 V bus the derating rule (typically 50% for solid tantalum) means this cap should not see more than 12.5 V DC bias — a common oversight that drives field failures.
The 2000-hour life at 125°C means the capacitor's wear-out mechanism is the dielectric aging, not the package — budget derating above 85°C to extend service life.
Housed in the 2917 (7343 Metric) case, size code E, measuring 7.30 mm x 4.30 mm with a seated height of 4.30 mm.