開關電源模塊因為其小型化、輕量化及高效率，相應的要求電解電容小型大容量化、耐紋波電流、高頻低阻、高溫長壽及更適應的高密度。高頻低阻抗是指電容器耐紋波電流能力強，且自身內(nèi)阻小，相對普通的而言，用在電路中產(chǎn)品自身不易發(fā)熱而導致提前失效。

　　Due to its miniaturization, light weight and high efficiency, the corresponding requirements of the switching power supply module are small and large capacity, ripple current resistance, high frequency and low resistance, long life at high temperature and more suitable high density. High frequency and low impedance means that the capacitor has strong ability to withstand ripple current, and its internal resistance is small. Relatively speaking, the product used in the circuit is not easy to heat itself and lead to premature failure.

　　開關電源輸出端用的濾波電容與工頻電路中的不一樣，在工頻電路中用作濾波的普通電解電容器，其上的脈動電壓頻率僅有100Hz，充放電時間是毫秒數(shù)量級，為獲得較小的脈動系數(shù)，需要的電容量高達數(shù)十萬微法，因此一般低頻用普通鋁電解電容器制造目標是以提高電容量為主。

　　The filter capacitor used in the output of switching power supply is different from that in power frequency circuit. The pulse voltage frequency of common electrolytic capacitor used as filter in power frequency circuit is only 100Hz, and the charging and discharging time is in the order of millisecond. In order to obtain a small ripple coefficient, the capacitance required is as high as hundreds of thousands of Micromethods. Therefore, the manufacturing goal of ordinary aluminum electrolytic capacitor for low frequency is to improve the quality of the capacitor High power capacity.

　　開關電源中作為輸出濾波用的電解電容，由于大多數(shù)的開關電源工作在方波或矩形波的狀態(tài)，含有及其豐富的高次諧波電壓與電流。

　　The electrolytic capacitor used as output filter in switching power supply contains abundant high-order harmonic voltage and current because most of the switching power supply work in the state of square wave or rectangular wave.

　　其上鋸齒波電壓的頻率高達數(shù)十千赫，甚至數(shù)十兆赫，它要求和低頻應用時不同，電容量并不是主要指標，衡量它好壞的是它的阻抗頻率特性。

　　The frequency of sawtooth voltage is as high as tens of kilohertz or even tens of megahertz, which is different from that in low frequency application. Capacitance is not the main index, but its impedance frequency characteristic is the measure of its quality.

　　開關電源輸出整流的電解電容，要求其阻抗頻率特性在300kHz甚至500kHz時仍不呈現(xiàn)上升趨勢。電解電容器ESR較低，能有效地濾除開關電源中的高頻紋波和尖峰電壓。

　　It is required that the impedance frequency characteristic of the electrolytic capacitor with rectifier output from switching power supply does not show an upward trend at 300kHz or even 500KHz. The ESR of electrolytic capacitor is low, which can effectively filter the high frequency ripple and peak voltage in switching power supply.

　　普通電解電容器在100kHz后就開始呈現(xiàn)上升趨勢，用于開關電源輸出整流濾波效果相對較差。

　　The common electrolytic capacitors begin to show an upward trend after 100kHz, and the filtering effect is relatively poor when applied to the output rectification and filtering of switching power supply.

　　電源模塊的輸出電容一般是采用高頻低阻，因為開關電源整流輸出的是高頻直流脈沖信號，必須要用高頻低阻電容來濾波，這樣才能降低電容自身損耗，不然電容長時間工作后會爆裂漏液。

　　The output capacitance of power module is generally high frequency and low resistance, because the rectifier output of switching power supply is high frequency DC pulse signal, it must be filtered by high frequency low resistance capacitor, so as to reduce the loss of capacitor itself, otherwise the capacitor will burst and leak after a long time of operation.