Distinguish:
1 Use an impedance meter to test whether it is within the qualified impedance
2 Whether the white paper such as SM/md is used for disassembly [generally yellow paper]
3 Whether high frequency low resistance electrolyte is selected

With the miniaturization and portability of switching power supply equipment and the rapid development of integrated circuits, this paper analyzes the requirements of the development of switching power supply on the performance of electrolytic capacitors as an important component of switching power supply, that is, miniaturization, high-frequency low impedance, long life and ripple current resistance must also be achieved.

Electrolytic capacitor is one of the most important devices in the primary and secondary circuit filter circuit of switching power supply. In general, the equivalent circuit of electrolytic capacitor can be considered as the series connection of ideal capacitor, parasitic inductance and equivalent series resistance. As we all know, the equivalent circuit of electrolytic capacitor is the main power supply of information household appliances today, making an indelible contribution to the miniaturization and portability of electronic equipment. With the continuous miniaturization, lightweight and high efficiency of switching power supply, it is used more and more in electronic equipment, and its popularity is higher and higher. Correspondingly, electrolytic capacitors are required to be small, large capacity, ripple current resistant, high-frequency and low impedance, high temperature and long life, and more suitable for high-density assembly.