Tantalum capacitor

An electrolytic capacitor with a porous tantalum anode and a thin tantalum oxide dielectric. Its high capacitance per volume makes it useful in compact electronic circuits.

Tantalum pentoxide: A dielectric oxide of tantalum with the chemical formula Ta₂O₅. A thin layer of this oxide separates the anode from the cathode and stores electric field energy.
Decoupling capacitor: A capacitor placed near a circuit load to reduce supply-voltage disturbances. Tantalum parts can provide local charge storage on power rails.
Aluminum electrolytic capacitor: A polarized capacitor that uses an aluminum oxide dielectric and an electrolyte. It often offers greater capacitance or surge tolerance at comparable cost, but typically occupies more volume.
Dielectric breakdown: The loss of insulating behavior in a dielectric under an excessive electric field. A local defect in tantalum oxide can create a conductive path and trigger failure.
Anodization: An electrochemical process that grows an oxide layer on a metal surface. It forms the controlled tantalum oxide dielectric on the anode.
Power-supply filtering: The use of circuit components to reduce unwanted variation in a power supply's output. Tantalum capacitors smooth voltage fluctuations in many low-voltage supplies.
Ceramic capacitor: A capacitor that uses ceramic material as its dielectric between metal electrodes. Ceramics are generally nonpolar and often better at high frequencies, while tantalum offers high capacitance in a small package.
Thermal runaway: A self-reinforcing rise in temperature caused when heating increases the process generating that heat. A shorted tantalum capacitor can draw rising current and ignite nearby material.
Porous tantalum: A sintered, porous form of tantalum metal with a large internal surface area. Its internal surface area allows a thin oxide film to provide substantial capacitance.
Ripple current: The alternating component of current flowing through a component alongside its direct-current load. Excess ripple current can heat a tantalum capacitor through its internal losses.

Linked from 6 pages