選擇旁(pang)路(lu)電容器時要考慮的(de)關鍵參數包括交流信號的(de)最(zui)低(di)頻率和電阻器的(de)阻值。在(zai)大多(duo)數情(qing)況下,最(zui)低(di)頻率為 50 Hz。
盡管不(bu)同類型(xing)的(de)(de)電容器可用(yong)于去耦(ou)/旁路應用(yong),但它們(men)的(de)(de)特性(xing)會(hui)根據所使用(yong)的(de)(de)介電材料和結構而有顯著差(cha)異(yi)。兩(liang)者決定了溫度(du)穩定性(xing)、線性(xing)度(du)、額定電壓、物理尺寸和成本(ben)。通常用(yong)于去耦(ou)應用(yong)的(de)(de)電容器類型(xing)包(bao)括陶瓷(ci)、鉭和鋁電解(jie)電容器。
陶瓷(ci)(ci)電(dian)容(rong)器的性能(neng)和成本使其成為去(qu)耦應用的流(liu)行選擇(ze)。這些電(dian)容(rong)器具有(you)低(di)等(deng)效(xiao)串聯電(dian)阻 (ESR) 和等(deng)效(xiao)串聯電(dian)感 (ESL)。此(ci)外,多層陶瓷(ci)(ci)電(dian)容(rong)器 (MLCC) 具有(you)多種封裝(zhuang)和電(dian)容(rong)值。陶瓷(ci)(ci)電(dian)容(rong)器是高頻電(dian)路去(qu)耦應用的絕(jue)佳選擇(ze)。
開關型鋁(lv)電(dian)解(jie)電(dian)容(rong)器(qi)通常(chang)用于低(di)(di)頻(pin)和中頻(pin)電(dian)子電(dian)路中的去耦應用。這些(xie)電(dian)容(rong)器(qi)價格低(di)(di)廉,電(dian)容(rong)值范圍廣,電(dian)容(rong)體(ti)積比高。然而,鋁(lv)電(dian)解(jie)電(dian)容(rong)器(qi)表現出與溫度相關的磨損(sun),并且在低(di)(di)溫下具有高 ESR。這些(xie)電(dian)容(rong)器(qi)廣泛(fan)用于消費產品的去耦應用。
固態鉭(tan)電(dian)容(rong)(rong)(rong)器具(ju)(ju)有高 CV,不易磨(mo)損。此外,它們(men)在低(di)溫下表現出令人印象(xiang)深(shen)刻的(de)穩(wen)定性。與鋁電(dian)解(jie)電(dian)容(rong)(rong)(rong)器相比,鉭(tan)電(dian)容(rong)(rong)(rong)器具(ju)(ju)有更(geng)高的(de)電(dian)容(rong)(rong)(rong)體積比和更(geng)低(di)的(de) ESR。另一方面,鉭(tan)電(dian)容(rong)(rong)(rong)器價(jia)格(ge)昂貴且僅限于(yu)低(di)電(dian)壓應(ying)用,通常高達(da) 50 V。這(zhe)些電(dian)容(rong)(rong)(rong)器通常用于(yu)可(ke)靠(kao)性更(geng)高的(de)應(ying)用。
聚(ju)酯、聚(ju)丙(bing)烯(xi)、特(te)氟隆和(he)聚(ju)苯乙烯(xi)電(dian)容(rong)器(qi)(qi)等薄膜(mo)電(dian)容(rong)器(qi)(qi)的(de)去(qu)耦應(ying)用(yong)有限(xian)。雖(sui)然(ran)這些電(dian)容(rong)器(qi)(qi)適用(yong)于高壓(ya)應(ying)用(yong)并且不易磨(mo)損,但生產它們的(de)成(cheng)本相對較高。然(ran)而,這些電(dian)容(rong)器(qi)(qi)的(de)特(te)性使其成(cheng)為高電(dian)壓(ya)、高電(dian)流和(he)音頻(pin)去(qu)耦應(ying)用(yong)的(de)合適選擇(ze)。
電(dian)(dian)(dian)容(rong)器(qi)是模擬和(he)數字電(dian)(dian)(dian)子(zi)電(dian)(dian)(dian)路(lu)中的(de)基本元件。它們用(yong)于廣泛的(de)應(ying)用(yong),包括耦合、去耦、濾波(bo)和(he)定(ding)時應(ying)用(yong)。耦合電(dian)(dian)(dian)容(rong)器(qi)允許交(jiao)流(liu)(liu)分量(liang)通過(guo),同時阻止直(zhi)(zhi)流(liu)(liu)分量(liang)。去耦電(dian)(dian)(dian)容(rong)器(qi)在電(dian)(dian)(dian)子(zi)電(dian)(dian)(dian)路(lu)中用(yong)作(zuo)儲能(neng)器(qi),以防止電(dian)(dian)(dian)壓快(kuai)速變(bian)化。旁路(lu)電(dian)(dian)(dian)容(rong)器(qi)通過(guo)將不需要的(de)交(jiao)流(liu)(liu)分量(liang)分流(liu)(liu)到地來清潔直(zhi)(zhi)流(liu)(liu)信號。電(dian)(dian)(dian)容(rong)器(qi)在很大程度上決定(ding)了電(dian)(dian)(dian)子(zi)電(dian)(dian)(dian)路(lu)的(de)性能(neng)、壽命和(he)可(ke)靠(kao)性。