6.8 µF, 20 V — bulk decoupling for 12 V rails
The TAJC685K020RNJ is a molded tantalum capacitor from the TAJ series, rated at 6.8 µF and 20 V with ±10% tolerance. The 20 V rating gives 60% derating margin on a 12 V supply — enough headroom for typical automotive load-dump transients without needing a higher-voltage part. ESR is specified at 2 Ohm — this sets the ripple current limit and output voltage ripple in a switching regulator. At 100 kHz switching frequency, the ripple voltage from the capacitor alone is 2 Ohm times the inductor ripple current; the rest comes from the output capacitor's bulk value.
The part can sit in an avionics LRU that sees -40°C cold-soak at altitude and 105°C near the engine firewall, or in a downhole tool that cycles from surface ambient to 125°C wellbore — the tantalum anode construction holds capacitance across the band better than MLCC.
Package — size code C, 2312
Manufacturer size code C, 2312 (6032 Metric) — 6.00 mm x 3.20 mm footprint, 2.80 mm seated height. The 2.80 mm height fits standard 2.5 mm board-to-board spacing with clearance. Surface-mount reflow profile per JEDEC J-STD-020 for tantalum; no special bake required below MSL 3.
No direct pin-compatible alternative from AVX, but the TAJ family covers the same footprint and ratings.