Tantalum is a hard and corrosion resistant silver-gray metal. Tantalum capacitor is a kind of electrolytic capacitor. The tantalum capacitor has an anode made of tantalum metal instead of aluminum. Tantalum capacitors have smaller dimensions and better tolerances than equivalent aluminum capacitors.
The use of tantalum in the capacitor makes it possible to form a very thin dielectric layer. This means a higher capacitance value per volume. It has superior frequency characteristics and better stability compared to other capacitor types.
Tantalum capacitors are polarizing devices. So it has a plus and a minus pole. This means that it can only be connected to a DC source, taking care of the correct terminal polarity. The side with the thick line or plus sign on the capacitor indicates the positive terminal. Capacitance value and maximum operating voltage are also written on the capacitor.
Tantalum capacitors are very sensitive to reverse polarization. A short-term applied reverse voltage causes the dielectric oxide layer to break down. For this reason, extreme care must be exercised during testing and assembly.
Tantalum capacitors can be either THT (Through-hole technology) or SMT (Surface-mount technology). The most commonly used is SMT, which takes up much less space on the printed circuit board.
Advantages of tantalum capacitor; small dimensions, high capacity, low leakage current, wide operating temperature range, long-term stability and reliability.
Tantalum capacitors fail when used outside the rated voltage or temperature. Tantalum capacitors can cause thermal runaways, small explosions and fires when they fail. This is the disadvantage of using a tantalum capacitor. Tantalum capacitors can be protected against failure by using safety components such as thermal fuse and current limiter.
Tantalum capacitors are more expensive than aluminum electrolytic capacitors and ceramic capacitors due to the unstable tantalum supply and manufacturing complexity. Therefore, the use of tantalum capacitors in general applications is rare. On the other hand, it is indispensable for certain applications despite its additional costs.
Tantalum capacitors are widely used for power supply filtering in televisions, computers and mobile phones due to their small size and long-term stability. They are extremely popular in medical electronics due to their high stability. It is also used in military applications because it has tight tolerances and a wide operating temperature range.
