Polypropylene capacitor

Low equivalent series resistance ESR, low loss factor DF and high reliability make them superior to electrolytic capacitors in switching power supplies. New plastic capacitor media, especially polypropylene, are used at switching power supply frequencies (20 to 60 kHz) and are more efficient and reliable than electrolytic capacitor media. The high efficiency of polypropylene dielectric capacitors allows us to use lower capacitance than electrolytic dielectric capacitors. The effective capacitance of a polypropylene capacitor is higher than that of an electrolytic capacitor of the same rating when measured at high frequencies. Moreover, in the filter circuit, polypropylene has a very low equivalent series resistance (ESR) value. Although plastic dielectric capacitors generally have a low loss factor, polypropylene capacitors are the lowest here, which is lower than polysulfonic acid, polycarbonate, polyester or even polystyrene.