The main function of electrolytic capacitors is to stabilize the current. There are many types of electrolytic capacitors. Today I want to tell you about high frequency electrolytic capacitors. What is the high frequency electrolytic capacitor? What is the role of high frequency electrolytic capacitor?
1. What is the difference between ordinary electrolytic capacitors and high-frequency electrolytic capacitors.
Ordinary electrolytic capacitors have the characteristics of large capacity, and they also have the disadvantage of leakage. The insulating material is electrolyte; the high-frequency capacitor has the advantages of high resistivity and small capacitance, and its insulating material is high in mica. The composition of the dielectric constant. Ordinary electrolytic capacitors are mainly used for power supply filtering. Leakage has little effect on the circuit. High-frequency capacitors are mainly used in high-frequency circuits. In high-frequency circuits, leakage is required to be small, and capacity requirements are small. Generally, small capacitors can be used.
2. Analysis of the role of high frequency electrolytic capacitors
High frequency capacitors should be selected in the switching power supply. The output filter electrolytic capacitor in the switching power supply has a sawtooth wave voltage frequency of up to several tens of kHz or even several tens of MHz. At this time, the capacitance is not its main indicator. The standard for measuring the quality of the capacitor is the “impedance-frequency” characteristic. It has a lower equivalent impedance in the operating frequency of the switching power supply, and has a good filtering effect on the high frequency spike signal generated when the semiconductor device operates.
