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，還要能夠管理電(dian)源(yuan)分(fen)配(pei)。

　　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(jin)墻壁時，怎樣的(de)(de)改變(bian)才(cai)是這(zhe)些設備期(qi)望(wang)的(de)(de)效(xiao)率(lv)呢?最新一代設備的(de)(de)設計采用(yong)了高效(xiao)率(lv)的(de)(de)開(kai)關充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)，以(yi)(yi)取代傳統的(de)(de)線性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)。當對電(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時，現在客戶(hu)(hu)不(bu)斷要求更短的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時間(jian)。使用(yong)開(kai)關充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)解決方案可以(yi)(yi)比(bi)傳統的(de)(de)線性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)有更高的(de)(de)效(xiao)率(lv)，此外，一個重要優(you)勢是能(neng)夠(gou)提高由電(dian)(dian)(dian)(dian)(dian)(dian)源提供的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流。在USB端口斷電(dian)(dian)(dian)(dian)(dian)(dian)時，可用(yong)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流可能(neng)被(bei)限制在不(bu)到500mA，這(zhe)個優(you)勢尤其重要。充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流越高，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)時間(jian)就(jiu)越短，因此可以(yi)(yi)滿足客戶(hu)(hu)的(de)(de)期(qi)望(wang)。

　　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，另一種是開(kai)關裝(zhuang)置。線性(xing)充(chong)電(dian)(dian)(dian)器已有較長的(de)(de)歷史。這類(lei)充(chong)電(dian)(dian)(dian)器通常具備一個比較有效的(de)(de)、簡單的(de)(de)方(fang)法為便(bian)(bian)攜式(shi)設備充(chong)電(dian)(dian)(dian)，噪(zao)聲最(zui)小(xiao)，又沒(mei)有很多(duo)外部元(yuan)件。但是，便(bian)(bian)攜式(shi)設備已變得(de)越來越復雜，增加(jia)了很多(duo)新的(de)(de)功能，所以需要更(geng)高的(de)(de)電(dian)(dian)(dian)池容量(liang)。很明(ming)顯，如果(guo)用(yong)(yong)戶想要在(zai)使用(yong)(yong)設備的(de)(de)同時(shi)(shi)給(gei)充(chong)電(dian)(dian)(dian)，由于(yu)功耗(hao)的(de)(de)緣故，線性(xing)充(chong)電(dian)(dian)(dian)器存在(zai)著一些弊(bi)端(duan)。在(zai)使用(yong)(yong)的(de)(de)同時(shi)(shi)充(chong)電(dian)(dian)(dian)所產生的(de)(de)熱量(liang)可能損壞系統(tong)或電(dian)(dian)(dian)池。這不(bu)是一個好現(xian)象(xiang)。

　　另一種選擇是開關裝置或開關模式電池充電器IC，它(ta)可以(yi)為電池提供更高水平(ping)的電流，而需要(yao)盡可能(neng)少的電力。從過往的經驗看，這類IC曾經存在一些噪(zao)聲問題。此外，前幾(ji)代的一些開關式裝置(zhi)還需要(yao)更多的外部元件。

　　然(ran)而(er)，開關式電池拓撲(pu)結(jie)構的優(you)勢(shi)也是顯(xian)而(er)易見。這些優(you)勢(shi)包括更高(gao)的效(xiao)率和更低的功耗，還(huan)有更短的充(chong)電時間(jian)。這些裝置還(huan)能利用(yong)較(jiao)高(gao)的輸入電壓充(chong)電，可(ke)(ke)以使用(yong)成本較(jiao)低的非穩壓適配器。這類裝置可(ke)(ke)以提高(gao)來自限(xian)流電流源的充(chong)電電流。