A tantalum capacitor is made of a tantalum powder core surrounded by tantalum pentoxide shell that is coated with with manganese dioxide, graphite, silver coating, solder resin. A tantalum wire extends axially into the core. Since 1960, tantalum caps have been shrinking due to higher-charge tantalum powders.
Advantages:
1. SMALLER – tantalum caps have a higher volumetric efficiency (CV/cc) when compared to other caps: A 10-microfarad tantalum cap can replace a 100-microfarad aluminum electrolytic cap. Tantalum caps are easily mounted in closely-confined spaces.
2. LOWER ESR – Excellent power dissipation characteristics. Tantalum caps have superior frequency characteristics than many other caps, including aluminum electrolytic caps. A comparable CV tantalum capacitor has an ESR ten times better than an aluminum electrolytic cap.
3. HIGHER RELIABILITY – Electrical performance qualities do not degrade over time: Tantalum caps do not lose capacitance; their shelf-life is unlimited.
4. SELF-HEALING – Any imperfections in the dieletric layer, the resistance of the manganese dioxide layer will typically convert to a form that is even more resistive. The new oxide form plugs up the faulty region and results in a reduction in current flow.
5. TEMPERATURE – -55 deg C to +125 deg F, with almost no electrical property degradation.
