Tantalum Capacitor
■
INTRODUCTION
Tantalum capacitor are designed with excellent performance characteristics for filtering, blocking,
and R.C tunning circuits. They are used extensively in industrial, commercial, entertainment and
medical electronic equipment. They exhibit the proven characteristics of wide temperature range
and long-term stability.
The advantages of tantalum capacitor electrolytic capacitor consist of their chemical stability, the
low thickness and high dielectric constant of the tantalum oxide layer, and the capability of
sintering anodes with a very large surface from tantalum powder.
The low reactivity of the tantalum oxide layer allows the employment of highly conductive
electrolytes, and thus achieves a low series resistance. Capacitance and dissipation factor in
relation to temperature and frequency thus prove to be very favourable. Additionally, there is also
the wide temperature range of several types form -55
℃
to +125
℃
.
A further advantage of the dielectric being inactive is a leakage current that is smaller than of
aluminium electrolytic capacitor which does not rise considerably even at dead storage. Tantalum
electrolytic capacitor thus show a very long life during operation and storage.
The capacitance of the tantalum electrolytic capacitor is very high due to the high dielectric
constant and the low thickness of tantalum oxide layer. The use of sintered anodes with a large
surface allows very small dimensions that cannot be reached or exceeded by any other capacitor.
The tantalum electrolytic capacitor at issue are polarized capacitors. In the case of polarized
electrolytic capacitor, the dielectric is structured in such a manner that the flow of current is
interrupted in one direction. It is therefore necessary to observe the indications regarding polarity
when using these capacitor(positive pole on anode and negative pole on cathode). In the case of
tantalum capacitor, a mispolarizing is permissible up to the values indicated in reversal voltage.
The tantalum capacitor is a polar electrolytic capacitor. The anode is a porous body of sintered
tantalum powder. A layer of tantalum oxide is formed over the whole sintered anode surface by
an electrolytic oxidation process.
This oxide layer, which has a high dielectric constant(
ε≒
27), functions as the dielectric medium of
the capacitor. The final thickness of the layer determines the rated working voltage of the
capacitor. Manganese dioxide, a solid semiconducting electrolytic, is deposited in the pores and on
the external surface of the formed anode to serve as the cathode. Electrical connection to the
cathode is effected by applying a metallic coating to the outer MnO2 layer.
As a result of the high stability of the oxide layer the leakage current to the capacitor is very
small, even after prolonged storage. The use of a solid semiconducting electrolytic guarantees high
stability of the electrical properties over long periods of time and over a wide range of
temperatures and frequencies.
-1-
Tantalum Capacitor
■
FEATURE AND APPLICATION
●
Feature
The product is a standard type that has been most widely used among tantalum chip capacitors.
- Molded Case available in four case codes.
- Compatible with automatic pick and place equipment.
- Meets or Exceeds EIA standard 535BAAC .
●
Application
- General electronic equipment
- Smoothing Circuit of DC-DC Converters & Output side of AC-DC Converters
- De-Coupling Circuit of High Speed ICs & MPUs
- Various Other High Frequency Circuit Applications
-2-
Analog electronics
京公网安备 11010802033920号
EEWORLD
