現在，大多數手持式設備都采用了兩種電池充電器，一(yi)種(zhong)是線性(xing)充電(dian)(dian)器，另一(yi)種(zhong)是開關(guan)充電(dian)(dian)器。線性(xing)充電(dian)(dian)器已有較長的歷史(shi)，充電(dian)(dian)方式比較簡(jian)單有效，噪聲很(hen)小，且沒有太(tai)多外部元(yuan)件。但是，隨(sui)著便(bian)攜式設備越來越復雜，新功能層出不窮，高容量電(dian)(dian)池的需求就更加強烈。線形充電(dian)(dian)器的缺(que)點(dian)是功耗太(tai)大，特別是在設備邊充電(dian)(dian)邊使用的時候尤為(wei)明顯，此時產生的熱量可能損壞系統(tong)或電(dian)(dian)池。

　　可供選(xuan)擇的有開關(guan)充電(dian)(dian)器或(huo)開關(guan)模(mo)式電(dian)(dian)池充電(dian)(dian)器IC，它(ta)可以使用盡可能少的電(dian)(dian)量，為電(dian)(dian)池提(ti)供更高的電(dian)(dian)流。從(cong)過往經驗來看(kan)，這(zhe)類IC一般會存在一些噪聲問題。此外，前幾(ji)代的開關(guan)式充電(dian)(dian)器還(huan)需要一些外部元件。

　　然而(er)，開關(guan)式電(dian)池拓撲結構的(de)(de)優勢也是顯而(er)易見。這些(xie)優勢包括更(geng)(geng)高(gao)的(de)(de)效率和(he)更(geng)(geng)低的(de)(de)功耗，還(huan)(huan)有更(geng)(geng)短(duan)的(de)(de)充電(dian)時(shi)間。此類裝(zhuang)置還(huan)(huan)能利用較(jiao)高(gao)的(de)(de)輸(shu)入電(dian)壓(ya)充電(dian)，使(shi)用成本較(jiao)低的(de)(de)非(fei)穩壓(ya)適配器。還(huan)(huan)可(ke)以提(ti)高(gao)來(lai)自限流電(dian)流源的(de)(de)充電(dian)電(dian)流。

　　開(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)通常(chang)在(zai)(zai)輕負(fu)載運行(xing)(xing)時會(hui)(hui)產生噪(zao)聲(sheng)，特別是在(zai)(zai)預處理(li)過程(cheng)中。隨著噪(zao)聲(sheng)的(de)減少，開(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)會(hui)(hui)進入脈(mo)沖跳躍(pulse skipping)模(mo)式(shi)(shi)運行(xing)(xing)。在(zai)(zai)脈(mo)沖跳躍模(mo)式(shi)(shi)中，PWM頻率異步變化(hua)。目(mu)前開(kai)發的(de)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)IC，可(ke)以(yi)在(zai)(zai)使用(yong)(yong)開(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)時提供高充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流，且(qie)對系統的(de)熱影響非常(chang)小(xiao)，而在(zai)(zai)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)下切換到線(xian)性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)，以(yi)減少噪(zao)聲(sheng)。這(zhe)種可(ke)提供線(xian)性模(mo)式(shi)(shi)的(de)PWM開(kai)關(guan)(guan)模(mo)式(shi)(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)可(ke)以(yi)在(zai)(zai)全恒流(快(kuai)速充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian))條件下實(shi)現高效率。開(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)可(ke)利用(yong)(yong)PWM開(kai)關(guan)(guan)穩(wen)壓器(qi)(qi)(qi)控制高達(da)2A的(de)恒流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。當(dang)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)處于(yu)(yu)預處理(li)過程(cheng)以(yi)及恒壓尖峰(feng)(taper)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)快(kuai)結束時，設(she)備會(hui)(hui)自動(dong)轉(zhuan)換到線(xian)形模(mo)式(shi)(shi)，以(yi)降(jiang)低(di)噪(zao)聲(sheng)，并利用(yong)(yong)開(kai)關(guan)(guan)模(mo)式(shi)(shi)加快(kuai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。一(yi)旦充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流值低(di)于(yu)(yu)300mA，線(xian)性模(mo)式(shi)(shi)會(hui)(hui)完全啟動(dong)，開(kai)關(guan)(guan)轉(zhuan)換器(qi)(qi)(qi)產生的(de)噪(zao)聲(sheng)就會(hui)(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(jie)決方案，它的充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流高達1A，具(ju)備先(xian)進的電(dian)(dian)(dian)(dian)充(chong)滿顯示功能，可(ke)以實現全(quan)(quan)程充(chong)電(dian)(dian)(dian)(dian)系(xi)統監(jian)控。符合(he)USB標準的100mA/500mA充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流設置有助于(yu)實現可(ke)編程預充(chong)電(dian)(dian)(dian)(dian)和快速充(chong)電(dian)(dian)(dian)(dian)。許多產品還具(ju)備電(dian)(dian)(dian)(dian)池溫(wen)度(du)監(jian)測功能，以確保安全(quan)(quan)充(chong)電(dian)(dian)(dian)(dian)。

　　Intersil等公司正在開(kai)發新(xin)一代充(chong)電(dian)(dian)器(qi)IC技術。這些完全集成的解決(jue)方案非常適合緊湊(cou)型(xing)(xing)應(ying)用，還能(neng)為高功率應(ying)用提供(gong)充(chong)電(dian)(dian)控制功能(neng)。目前，充(chong)電(dian)(dian)電(dian)(dian)壓精度(du)能(neng)達到0.5%，較前幾年(nian)的1%有很大改善。開(kai)關頻率可(ke)達3MHz，而(er)且新(xin)型(xing)(xing)開(kai)關充(chong)電(dian)(dian)器(qi)可(ke)提供(gong)高達2A的充(chong)電(dian)(dian)電(dian)(dian)流，最新(xin)的一個(ge)應(ying)用實例(li)是ISL9220，它適用于一節和兩(liang)節鋰離子電(dian)(dian)池應(ying)用。

　　另外，新設計還(huan)可以限制泄(xie)漏，目前在沒有加上輸入(ru)功率時，典型(xing)的泄(xie)漏電(dian)流已低于0.5uA。而且這(zhe)些改進還(huan)可以用(yong)于更(geng)小的封裝，如4mm×4mm QFN或2mm×2mm CSP，以節省手(shou)持(chi)式設備(bei)的設計空間。

　　最新的電池充電器IC還能夠監視輸入電(dian)(dian)(dian)壓、電(dian)(dian)(dian)池電(dian)(dian)(dian)壓和(he)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流。當三個(ge)參數中任意一個(ge)超出特(te)定限額時，該IC就會關(guan)閉內部N溝道(dao)MOSFET，使充(chong)電(dian)(dian)(dian)系統(tong)停止對電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)。利用這(zhe)些重(zhong)要的器件可(ke)以(yi)靈活地(di)提高(gao)效率，這(zhe)對持(chi)續(xu)增長、功能不斷擴(kuo)充(chong)的移動(dong)、手持(chi)式產品(pin)是至關(guan)重(zhong)要的。