In the design process of power supply, there are many factors that need to be taken into consideration, including filtering, decoupling, and bypass, all of which are directly related to the chip capacitor. Therefore, in the design of power supply, there must be the composition of capacitors.

In power supply design applications, chip capacitors are mainly used for filtering and decoupling/bypass. Filtering mainly refers to filtering out external noise, while decoupling/bypass is to reduce external noise interference in local circuits. Many people easily confuse the two. Let's take a look at a circuit structure:

National giant agents generally use large capacity capacitors for filtering, which do not require fast speed, but have high requirements for capacitance values. Generally, Aluminium electrolytic capacitor is used. When the surge current is small, it is better to use tantalum capacitor instead of Aluminium electrolytic capacitor. From the above example, we can see that as a decoupling capacitor, it must have a fast response speed to achieve the effect. If the local circuit A in the figure refers to a chip, then the decoupling capacitor should use a ceramic chip capacitor, and the chip capacitor should be as close to the power pin of the chip as possible. If "local circuit A" refers to a functional module, ceramic chip capacitor can be used. If the capacity is insufficient, tantalum capacitor or Aluminium electrolytic capacitor can also be used (provided that each chip in the functional module has decoupling capacitor ceramic chip capacitor). The capacity of the filter capacitor can often be calculated by formulas found in the data manual of the switching power supply chip. If the filter circuit uses electrolytic capacitor, tantalum capacitor and ceramic chip capacitor at the same time, place the electrolytic capacitor closest to the power off to protect the tantalum capacitor. The ceramic capacitor is placed behind the tantalum capacitor. This can achieve the best filtering effect.