What is the purpose of a capacitor?

Capacitors are two conductors close to each other with a layer of non-conductive insulating medium sandwiched between them, forming a capacitor. Capacitors are roughly used for the following three purposes.

First, energy storage purposes when the power supply transient break or IC drive speed rise rapidly resulting in an increase in load current, the power line voltage drops, which may lead to IC failure. To prevent failure, the charge stored in the capacitor when the power line is normal is provided to the IC side and the power line voltage is temporarily maintained.

Second, decoupling purposes in order to provide a stable DC voltage, remove the external inductive noise overlapping the power line and high-frequency noise caused by high-speed circuit driving. For general power supply circuits.

Third, coupling purposes are generally used in audio circuits. Capacitors are of various types and widely used. Aluminum electrolytic capacitors and tantalum electrolytic capacitors are suitable for low-frequency terminals, mainly in the memory and low-frequency filter fields. In the medium frequency range, ceramic capacitors are more suitable for decoupling capacitors and high frequency filters. Special low loss ceramic capacitors and mica capacitors are suitable for high frequency applications and microwave circuits.