Tantalum Capacitor

 
Tantalum Capacitor

What are tantalum capacitors? Tantalum capacitors are a subtype of electrolytic capacitors. They are made of tantalum metal which acts as an anode, covered by a layer of oxide which acts as the dielectric, surrounded by a conductive cathode. The use of tantalum allows for a very thin dielectric layer. This results in a higher capacitance value per volume, superior frequency characteristics compared to many other types of capacitors and excellent stability over time. Tantalum capacitors are generally polarized, which means that they may only be connected to a DC supply observing the correct terminal polarity. The downside to using tantalum capacitors is their unfavorable failure mode which may lead to thermal runaway, fires and small explosions, but this can be prevented through the use of external failsafe devices such as current limiters or thermal fuses. Technology advances allow tantalum capacitors to be used in a wide variety of circuits, often found in laptops, automotive industry, cell phones and others, most often in the form of surface mounted devices (SMD). These surface mount tantalum capacitors claim much less space on the printed circuit board and allow for greater packing densities. Tantalum capacitor definition Tantalum capacitors are electrolytic capacitors which use tantalum metal for the anode. They are polarized capacitors with superior frequency and stability characteristics. Characteristics General characteristics Tantalum capacitors are made with capacitance values ranging from 1nF all the way to 72mF and they are much smaller in size than aluminum electrolytic capacitors of the same capacitance. The voltage rating for tantalum capacitors varies from 2V to more than 500V.  They have an equivalent series resistance (ESR) ten times smaller than the ESR of aluminum electrolytic capacitors, which allows for larger currents to pass through the capacitor with less heat generated. Tantalum capacitors are very stable over time and [… read more]