現在，大多數手持式設備都采用了兩種電池充電器，一種(zhong)是(shi)線(xian)性充(chong)電(dian)(dian)(dian)(dian)器(qi)，另一種(zhong)是(shi)開(kai)關充(chong)電(dian)(dian)(dian)(dian)器(qi)。線(xian)性充(chong)電(dian)(dian)(dian)(dian)器(qi)已有較長的(de)(de)歷史，充(chong)電(dian)(dian)(dian)(dian)方(fang)式(shi)(shi)比較簡單有效，噪聲很小，且沒有太多(duo)外部元(yuan)件(jian)。但(dan)是(shi)，隨著(zhu)便攜(xie)式(shi)(shi)設(she)備越(yue)來越(yue)復雜，新功能(neng)層出不窮(qiong)，高容量電(dian)(dian)(dian)(dian)池(chi)的(de)(de)需求就(jiu)更加強烈(lie)。線(xian)形充(chong)電(dian)(dian)(dian)(dian)器(qi)的(de)(de)缺點是(shi)功耗太大(da)，特別是(shi)在(zai)設(she)備邊充(chong)電(dian)(dian)(dian)(dian)邊使用(yong)的(de)(de)時候(hou)尤(you)為(wei)明顯，此時產生的(de)(de)熱量可能(neng)損壞系(xi)統(tong)或電(dian)(dian)(dian)(dian)池(chi)。

　　可供(gong)選(xuan)擇的有(you)開(kai)(kai)關充電(dian)器(qi)或開(kai)(kai)關模式電(dian)池充電(dian)器(qi)IC，它可以使用盡可能(neng)少的電(dian)量，為電(dian)池提(ti)供(gong)更高的電(dian)流。從過往經驗來看，這類(lei)IC一般會存在一些(xie)噪(zao)聲問題。此外，前幾(ji)代的開(kai)(kai)關式充電(dian)器(qi)還需要一些(xie)外部元件。

　　然而(er)，開關式電(dian)池拓撲結構的(de)(de)優(you)勢也是(shi)顯而(er)易見。這些優(you)勢包(bao)括更高(gao)(gao)的(de)(de)效率和更低(di)的(de)(de)功(gong)耗，還(huan)有(you)更短的(de)(de)充電(dian)時間。此類裝置還(huan)能利用(yong)較(jiao)高(gao)(gao)的(de)(de)輸入電(dian)壓(ya)充電(dian)，使用(yong)成本較(jiao)低(di)的(de)(de)非穩壓(ya)適配(pei)器。還(huan)可以提高(gao)(gao)來自限流電(dian)流源的(de)(de)充電(dian)電(dian)流。

　　開(kai)(kai)(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)通(tong)常在(zai)輕負(fu)載(zai)運(yun)行(xing)時會(hui)產(chan)生噪聲(sheng)，特別是在(zai)預(yu)處(chu)理過程中。隨著噪聲(sheng)的(de)減少，開(kai)(kai)(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)會(hui)進入脈沖(chong)跳(tiao)躍(pulse skipping)模(mo)(mo)(mo)(mo)式(shi)運(yun)行(xing)。在(zai)脈沖(chong)跳(tiao)躍模(mo)(mo)(mo)(mo)式(shi)中，PWM頻率(lv)異步變化。目前(qian)開(kai)(kai)(kai)發的(de)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)IC，可(ke)(ke)以(yi)(yi)(yi)在(zai)使用開(kai)(kai)(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)時提供高(gao)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，且對系(xi)統的(de)熱(re)影響非常小，而(er)在(zai)低電(dian)(dian)(dian)(dian)(dian)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模(mo)(mo)(mo)(mo)式(shi)下切換(huan)到線(xian)(xian)性(xing)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)，以(yi)(yi)(yi)減少噪聲(sheng)。這種可(ke)(ke)提供線(xian)(xian)性(xing)模(mo)(mo)(mo)(mo)式(shi)的(de)PWM開(kai)(kai)(kai)關(guan)(guan)模(mo)(mo)(mo)(mo)式(shi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)可(ke)(ke)以(yi)(yi)(yi)在(zai)全(quan)恒(heng)(heng)流(快速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian))條件下實現高(gao)效率(lv)。開(kai)(kai)(kai)關(guan)(guan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)可(ke)(ke)利(li)用PWM開(kai)(kai)(kai)關(guan)(guan)穩壓器(qi)控制高(gao)達2A的(de)恒(heng)(heng)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。當電(dian)(dian)(dian)(dian)(dian)池(chi)處(chu)于預(yu)處(chu)理過程以(yi)(yi)(yi)及恒(heng)(heng)壓尖峰(taper)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模(mo)(mo)(mo)(mo)式(shi)快結束時，設備會(hui)自動轉(zhuan)換(huan)到線(xian)(xian)形(xing)模(mo)(mo)(mo)(mo)式(shi)，以(yi)(yi)(yi)降(jiang)低噪聲(sheng)，并利(li)用開(kai)(kai)(kai)關(guan)(guan)模(mo)(mo)(mo)(mo)式(shi)加快充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。一旦充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流值低于300mA，線(xian)(xian)性(xing)模(mo)(mo)(mo)(mo)式(shi)會(hui)完全(quan)啟動，開(kai)(kai)(kai)關(guan)(guan)轉(zhuan)換(huan)器(qi)產(chan)生的(de)噪聲(sheng)就會(hui)消除。

　　 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(jue)方案(an)，它(ta)的(de)(de)充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流高達1A，具(ju)(ju)備先進的(de)(de)電(dian)(dian)(dian)(dian)充(chong)滿顯示功(gong)能(neng)，可以實現全程充(chong)電(dian)(dian)(dian)(dian)系(xi)統監(jian)控。符合USB標準的(de)(de)100mA/500mA充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流設置有助于實現可編程預充(chong)電(dian)(dian)(dian)(dian)和快速充(chong)電(dian)(dian)(dian)(dian)。許多(duo)產(chan)品還具(ju)(ju)備電(dian)(dian)(dian)(dian)池溫度(du)監(jian)測功(gong)能(neng)，以確保安全充(chong)電(dian)(dian)(dian)(dian)。

　　Intersil等公司正在開發新(xin)(xin)一(yi)代(dai)充電(dian)器IC技術(shu)。這些完全集成的(de)(de)解決方案非常適(shi)合(he)緊湊型(xing)應(ying)用(yong)，還能(neng)為高功率應(ying)用(yong)提供充電(dian)控制功能(neng)。目前，充電(dian)電(dian)壓(ya)精度(du)能(neng)達到0.5%，較前幾年的(de)(de)1%有很大改善。開關頻(pin)率可達3MHz，而且新(xin)(xin)型(xing)開關充電(dian)器可提供高達2A的(de)(de)充電(dian)電(dian)流，最新(xin)(xin)的(de)(de)一(yi)個應(ying)用(yong)實(shi)例是ISL9220，它適(shi)用(yong)于一(yi)節和(he)兩(liang)節鋰離子電(dian)池應(ying)用(yong)。

　　另外，新設(she)計還(huan)可以限制泄(xie)漏，目前在(zai)沒有加上輸入功(gong)率(lv)時，典型的泄(xie)漏電流已低于0.5uA。而且這些改進還(huan)可以用(yong)于更小的封裝，如4mm×4mm QFN或2mm×2mm CSP，以節省手持式設(she)備的設(she)計空(kong)間。

　　最新的電池充電器IC還能(neng)夠監視輸入電(dian)壓(ya)(ya)、電(dian)池電(dian)壓(ya)(ya)和充電(dian)電(dian)流。當三個參數中任意一個超出特定限額時，該(gai)IC就會關(guan)閉內(nei)部(bu)N溝道MOSFET，使充電(dian)系統停止對(dui)電(dian)池充電(dian)。利用這些(xie)重要的(de)(de)器(qi)件可以靈活地提高(gao)效率，這對(dui)持續增長、功(gong)能(neng)不斷擴(kuo)充的(de)(de)移(yi)動、手持式產(chan)品(pin)是至關(guan)重要的(de)(de)。