6.8 µF at 50 V — bulk decoupling for a 48 V rail
The TAJC685K050HNJ: This is a size C (2312 metric) molded tantalum capacitor from the TAJ series, rated 6.8 µF with a 50 V DC voltage rating. The ±10% tolerance is the standard production band. At 50 V, this part suits bulk decoupling on a 48 V telecom bus or a high-side rail where a ceramic capacitor of equivalent capacitance would de-rate to near zero at the bias voltage.
1 Ohm ESR — ripple current and output noise
The ESR is specified at 1 Ohm measured at 100 kHz. For a 6.8 µF capacitor at 50 V, 1 Ohm is typical for this case size; it sets the ripple current capability at roughly 300 mA RMS at 125°C. The ESR also dominates the output noise in a switching regulator — a 100 kHz ripple current of 100 mA produces 100 mV of ripple voltage across the ESR alone.
The rated lifetime is 2000 hours at 125°C with full rated voltage applied. This is the standard tantalum endurance test condition. In an engine-bay or downhole environment where ambient temperature exceeds 85°C, derating the applied voltage by 20% (to 40 V) typically extends useful life beyond the 2000-hour mark.
KYOCERA AVX lists this order code as Active. No last-time-buy or end-of-life notification has been published.