Tantalum capacitors offer high
volumetric efficiency (CV/cc) compared with
other capacitors types. In many applications, a
tantalum capacitor can be 10 times smaller than
comparable aluminium capacitor. A 100 microfarad
aluminium can be replaced with a 10 microfarad
tantalum.
Tantalum capacitors have better
frequency characteristics than other types of
capacitors, especially aluminium electrolytic
capacitors. Typically, an identical CV tantalum
has 10 times better ESR than an aluminium one.
Tantalum capacitors have a wide
operating range, -55 degrees C to +125 degrees
C, and experience minimal degradation in
electrical properties over this temperature
range.
Tantalum capacitors have a unique
"self-healing" mechanism that results in a
decreasing failure rate over time. If a tantalum
capacitor has an impurity or imperfection in the
dielectric layer, a heavy current will flow
through the site when a DC current is applied.
Resistance of the MnO2 layer to this current
causes localized heating and converts the MnO2
to a more resistive form, typically Mn2O3. This
new oxide plugs up the fault site and reduces
the current flow.
These properties make tantalum
capacitors ideal for use in miniaturised
electrical equipment such as mobile phones and
lap top computers.
