What role does electrolytic capacitor play in switching power supply?
The functions of electrolytic capacitors in switching power supplies include bypass, decoupling, filtering, and energy storage.
1. Bypass capacitor is an energy storage device that provides energy to local devices, which can make the output of the voltage regulator uniform and reduce load demand. Just like small rechargeable batteries, bypass capacitors can be charged and discharged to the device.
2. Decoupling: specifically refers to the removal of noise on the power supply pins of a chip, which is generated by the operation of the chip itself. Configuring decoupling capacitors can suppress noise caused by load changes and is a common practice in the reliability design of printed circuit boards.
3. Filtering: Capacitors convert voltage changes into current changes, and the higher the frequency, the greater the peak current, thus buffering the voltage. Filtering is the process of charging and discharging.
Electrolytic capacitor is a type of capacitor, with a metal foil as the positive electrode (aluminum or tantalum), and an oxide film (aluminum oxide or tantalum pentoxide) closely attached to the positive electrode as the dielectric. The cathode is composed of conductive materials, electrolytes (electrolytes can be liquid or solid), and other materials. Because electrolytes are the main part of the cathode, electrolytic capacitors are named after them. Simultaneously, the positive and negative terminals of the electrolytic capacitor must not be connected incorrectly. Aluminum electrolytic capacitors can be divided into four categories: lead type aluminum electrolytic capacitors; Bull horn aluminum electrolytic capacitor; Bolt type aluminum electrolytic capacitor; Solid state aluminum electrolytic capacitors.
