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(xian)性充(chong)電(dian)器(qi)，另一種是開關充(chong)電(dian)器(qi)。線(xian)性充(chong)電(dian)器(qi)已(yi)有(you)較長的歷史，充(chong)電(dian)方式(shi)比較簡單(dan)有(you)效，噪聲很(hen)小，且沒有(you)太多(duo)外部元件。但是，隨(sui)著便攜式(shi)設備(bei)(bei)越來(lai)越復雜，新功能(neng)層(ceng)出不窮，高容量電(dian)池的需求就更(geng)加強烈。線(xian)形充(chong)電(dian)器(qi)的缺點是功耗(hao)太大，特別是在設備(bei)(bei)邊充(chong)電(dian)邊使用(yong)的時候尤為明(ming)顯，此時產生的熱(re)量可能(neng)損壞系統或(huo)電(dian)池。

　　可供選擇的(de)有開(kai)關充(chong)電(dian)器或開(kai)關模(mo)式電(dian)池充(chong)電(dian)器IC，它可以使用盡可能少的(de)電(dian)量，為電(dian)池提供更高的(de)電(dian)流。從(cong)過(guo)往經驗來看，這類IC一(yi)般會存(cun)在一(yi)些噪(zao)聲(sheng)問題。此外(wai)，前(qian)幾(ji)代的(de)開(kai)關式充(chong)電(dian)器還需要一(yi)些外(wai)部元件。

　　然而(er)，開關式電(dian)池拓撲結構(gou)的(de)(de)(de)優勢也是(shi)顯而(er)易見。這些優勢包括更高(gao)的(de)(de)(de)效率和更低(di)的(de)(de)(de)功(gong)耗(hao)，還有(you)更短的(de)(de)(de)充電(dian)時間。此類(lei)裝置還能利用(yong)較高(gao)的(de)(de)(de)輸入電(dian)壓充電(dian)，使(shi)用(yong)成本較低(di)的(de)(de)(de)非(fei)穩(wen)壓適配器。還可以提高(gao)來自限流(liu)電(dian)流(liu)源(yuan)的(de)(de)(de)充電(dian)電(dian)流(liu)。

　　開關(guan)(guan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)通常(chang)在(zai)輕負載運行時(shi)會(hui)產生噪(zao)聲，特別(bie)是在(zai)預處理(li)過程(cheng)中(zhong)。隨著(zhu)噪(zao)聲的(de)減少(shao)，開關(guan)(guan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)會(hui)進入脈(mo)沖(chong)跳(tiao)躍(yue)(pulse skipping)模(mo)式(shi)(shi)運行。在(zai)脈(mo)沖(chong)跳(tiao)躍(yue)模(mo)式(shi)(shi)中(zhong)，PWM頻率(lv)(lv)異步變化(hua)。目前開發的(de)電(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)IC，可(ke)(ke)以(yi)(yi)在(zai)使用(yong)開關(guan)(guan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)時(shi)提(ti)供高充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)，且(qie)對系統的(de)熱影響非常(chang)小，而(er)在(zai)低(di)電(dian)(dian)(dian)(dian)流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)下(xia)切換到線(xian)(xian)性充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)，以(yi)(yi)減少(shao)噪(zao)聲。這種可(ke)(ke)提(ti)供線(xian)(xian)性模(mo)式(shi)(shi)的(de)PWM開關(guan)(guan)模(mo)式(shi)(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)可(ke)(ke)以(yi)(yi)在(zai)全恒(heng)(heng)流(liu)(liu)(快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian))條件下(xia)實現高效(xiao)率(lv)(lv)。開關(guan)(guan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)可(ke)(ke)利用(yong)PWM開關(guan)(guan)穩壓器(qi)(qi)控制(zhi)高達2A的(de)恒(heng)(heng)流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。當(dang)電(dian)(dian)(dian)(dian)池(chi)處于(yu)(yu)預處理(li)過程(cheng)以(yi)(yi)及恒(heng)(heng)壓尖峰(taper)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)快結束時(shi)，設備會(hui)自動轉(zhuan)換到線(xian)(xian)形模(mo)式(shi)(shi)，以(yi)(yi)降低(di)噪(zao)聲，并利用(yong)開關(guan)(guan)模(mo)式(shi)(shi)加快充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。一旦充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)(liu)值低(di)于(yu)(yu)300mA，線(xian)(xian)性模(mo)式(shi)(shi)會(hui)完全啟動，開關(guan)(guan)轉(zhuan)換器(qi)(qi)產生的(de)噪(zao)聲就會(hui)消除(chu)。

　　 但是，現在充電技術有了進一步的發展。例如，一種用于新型手持式設備的單節鋰離子/聚合物電池充電器解決方案，它(ta)的(de)充(chong)(chong)(chong)電(dian)電(dian)流高達1A，具(ju)備先(xian)進的(de)電(dian)充(chong)(chong)(chong)滿顯示功(gong)能，可以實(shi)(shi)現全程充(chong)(chong)(chong)電(dian)系統監(jian)控。符合USB標(biao)準的(de)100mA/500mA充(chong)(chong)(chong)電(dian)電(dian)流設(she)置有助于實(shi)(shi)現可編程預充(chong)(chong)(chong)電(dian)和(he)快速(su)充(chong)(chong)(chong)電(dian)。許多產品還具(ju)備電(dian)池溫度(du)監(jian)測功(gong)能，以確保(bao)安全充(chong)(chong)(chong)電(dian)。

　　Intersil等公司正(zheng)在開發新(xin)一代充電(dian)器IC技術(shu)。這些完全(quan)集成(cheng)的解決方案非常(chang)適合緊(jin)湊型應用(yong)，還能為高(gao)功率應用(yong)提供充電(dian)控(kong)制(zhi)功能。目前，充電(dian)電(dian)壓精(jing)度能達到0.5%，較前幾年的1%有(you)很大改善。開關頻(pin)率可達3MHz，而且新(xin)型開關充電(dian)器可提供高(gao)達2A的充電(dian)電(dian)流，最新(xin)的一個(ge)應用(yong)實例是ISL9220，它適用(yong)于一節(jie)和兩節(jie)鋰離子電(dian)池(chi)應用(yong)。

　　另外，新設計還(huan)可以(yi)限(xian)制泄(xie)漏(lou)，目前在沒有加上輸(shu)入功率(lv)時，典型的泄(xie)漏(lou)電(dian)流已低于0.5uA。而且這些改進還(huan)可以(yi)用于更小的封(feng)裝，如4mm×4mm QFN或2mm×2mm CSP，以(yi)節省手持式設備的設計空間(jian)。

　　最新的電池充電器IC還能夠監(jian)視輸入(ru)電(dian)(dian)(dian)(dian)壓(ya)、電(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)壓(ya)和充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流。當三個參數中任意(yi)一個超(chao)出特定(ding)限額時，該IC就會(hui)關(guan)閉內部N溝(gou)道MOSFET，使充(chong)電(dian)(dian)(dian)(dian)系統停止對電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)。利(li)用這(zhe)(zhe)些重要的器件可(ke)以靈活(huo)地提高(gao)效率(lv)，這(zhe)(zhe)對持續增長、功能不(bu)斷擴(kuo)充(chong)的移動、手持式產品是至關(guan)重要的。