High-temperature hold-up for low-voltage rails
The TAJD687K004RNJV: This TAJ series molded tantalum capacitor delivers 680 µF at 4 V in a standard 2917 (7343 Metric) SMD package — a common choice for bulk decoupling on 3.3 V or 1.8 V rails where the ripple current and voltage margin need a low-ESR electrolytic alternative.
ESR and ripple — what the 500 mOhm spec means
With 500 mOhm ESR measured at 100 kHz, the self-heating from ripple current stays manageable — for a 1 A ripple component, the I²R loss is 0.5 W, which the 2917 package can dissipate with reasonable board copper. The ±10% tolerance on 680 µF means the actual capacitance at 25°C falls between 612 µF and 748 µF — enough margin for a bulk cap in a switching regulator output filter without oversizing the feedback compensation.
Active production — ordering and fit
The molded case carries no polarity marking ambiguity — tantalum capacitors are polarized, and the device is marked with a stripe on the positive end. Confirm orientation against the board silkscreen before reflow.