電池充電器IC的改進的一大好處
今天是一個全球無線互聯的時代,幾乎沒有什么比保持智能手機或移動互聯網設備的充電那么重要。不斷改善的便攜式和手持式設備擴展的功能帶給電池充電器集成電路(IC)設計人員一個嚴峻的挑戰。高分辨率屏幕和更大的存儲能力結合電池所具備的新功能,都需要電池充電器技(ji)術不僅更高效,還要(yao)能夠管理電源分配。
功耗的優化可以延長電池壽命,這一直是手持式電源管理的動力。但是,當把手持式設備的充電器插座插進墻壁(bi)時(shi)(shi),怎(zen)樣(yang)的改(gai)變才是這些設備期望的效率呢?最(zui)新一代設備的設計(ji)采用了高效率的開關(guan)(guan)充電(dian)(dian)(dian)(dian)(dian)(dian)器(qi),以取代傳(chuan)(chuan)統(tong)的線性充電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)。當對電(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi),現在(zai)客戶不斷要(yao)(yao)(yao)求更(geng)短的充電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間。使用開關(guan)(guan)充電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)解(jie)決方案(an)可以比傳(chuan)(chuan)統(tong)的線性充電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)有更(geng)高的效率,此(ci)外(wai),一個重要(yao)(yao)(yao)優勢是能夠提高由電(dian)(dian)(dian)(dian)(dian)(dian)源提供(gong)的充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流。在(zai)USB端(duan)口斷電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi),可用的電(dian)(dian)(dian)(dian)(dian)(dian)流可能被限制在(zai)不到(dao)500mA,這個優勢尤其重要(yao)(yao)(yao)。充電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流越高,充電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)間就越短,因(yin)此(ci)可以滿足(zu)客戶的期望。
現在,大多數手持式設備都采用了兩種電池充電器,一種是線性充電器,另一(yi)種是開(kai)關裝置。線性(xing)充電(dian)(dian)器(qi)已(yi)有較(jiao)長的(de)歷史。這(zhe)類充電(dian)(dian)器(qi)通常具備(bei)一(yi)個比較(jiao)有效的(de)、簡單的(de)方法為便攜式設備(bei)充電(dian)(dian),噪(zao)聲最小(xiao),又(you)沒有很(hen)多(duo)外部(bu)元件。但是,便攜式設備(bei)已(yi)變得越來越復雜,增加了很(hen)多(duo)新(xin)的(de)功能,所(suo)(suo)以需要更高的(de)電(dian)(dian)池(chi)(chi)容量。很(hen)明顯,如(ru)果用(yong)戶想要在(zai)使用(yong)設備(bei)的(de)同(tong)時給(gei)充電(dian)(dian),由于功耗(hao)的(de)緣故,線性(xing)充電(dian)(dian)器(qi)存在(zai)著一(yi)些弊端。在(zai)使用(yong)的(de)同(tong)時充電(dian)(dian)所(suo)(suo)產生的(de)熱量可能損壞系統或(huo)電(dian)(dian)池(chi)(chi)。這(zhe)不是一(yi)個好(hao)現象。
另一種選擇是開關裝置或開關模式電池充電器IC,它可(ke)以為電(dian)池提(ti)供更高水平的(de)電(dian)流,而需要盡可(ke)能少的(de)電(dian)力。從過(guo)往的(de)經驗(yan)看,這類(lei)IC曾經存在一些噪聲(sheng)問題。此外,前(qian)幾(ji)代的(de)一些開關式裝置還需要更多(duo)的(de)外部元件。
然(ran)而(er),開關式電(dian)池(chi)拓撲結構(gou)的(de)(de)優(you)勢(shi)(shi)也是(shi)顯而(er)易見。這些(xie)優(you)勢(shi)(shi)包括(kuo)更高(gao)的(de)(de)效率和更低的(de)(de)功耗,還有(you)更短的(de)(de)充電(dian)時間。這些(xie)裝置(zhi)還能利用較高(gao)的(de)(de)輸(shu)入電(dian)壓(ya)充電(dian),可以使用成本(ben)較低的(de)(de)非(fei)穩壓(ya)適配器(qi)。這類裝置(zhi)可以提(ti)高(gao)來自限流(liu)電(dian)流(liu)源的(de)(de)充電(dian)電(dian)流(liu)。