現在，大多數手持式設備都采用了兩種電池充電器，一種是(shi)線性(xing)充(chong)(chong)電(dian)器(qi)，另一種是(shi)開關充(chong)(chong)電(dian)器(qi)。線性(xing)充(chong)(chong)電(dian)器(qi)已有較長(chang)的歷史，充(chong)(chong)電(dian)方式比較簡單有效，噪(zao)聲很(hen)小，且沒有太多外部元件。但是(shi)，隨著便(bian)攜式設備越來越復雜，新功能層出(chu)不窮，高容量電(dian)池的需求就更加強(qiang)烈(lie)。線形(xing)充(chong)(chong)電(dian)器(qi)的缺(que)點是(shi)功耗太大(da)，特別是(shi)在設備邊(bian)充(chong)(chong)電(dian)邊(bian)使用的時候(hou)尤(you)為明顯(xian)，此時產生的熱量可能損壞系(xi)統或電(dian)池。

　　可供選擇的(de)有開(kai)關充(chong)電器(qi)或開(kai)關模式(shi)電池充(chong)電器(qi)IC，它可以使(shi)用(yong)盡可能少(shao)的(de)電量，為電池提供更高的(de)電流。從過往經驗來看，這類(lei)IC一般會存在(zai)一些噪(zao)聲問題。此(ci)外(wai)，前幾代的(de)開(kai)關式(shi)充(chong)電器(qi)還需要一些外(wai)部(bu)元件(jian)。

　　然而，開關式電(dian)池(chi)拓撲結構(gou)的(de)優勢也是(shi)顯而易見(jian)。這些優勢包(bao)括更(geng)高的(de)效率和更(geng)低的(de)功耗(hao)，還有更(geng)短的(de)充電(dian)時間。此類裝置還能利用較高的(de)輸入電(dian)壓(ya)充電(dian)，使用成本較低的(de)非(fei)穩壓(ya)適(shi)配器。還可以(yi)提高來自(zi)限流(liu)(liu)電(dian)流(liu)(liu)源(yuan)的(de)充電(dian)電(dian)流(liu)(liu)。

　　開(kai)(kai)(kai)關充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)通常在(zai)(zai)輕負載(zai)運行(xing)時會產生噪聲(sheng)，特別是在(zai)(zai)預(yu)處(chu)理過(guo)程中(zhong)。隨著噪聲(sheng)的(de)(de)(de)(de)減(jian)少(shao)，開(kai)(kai)(kai)關充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)會進(jin)入脈沖(chong)跳躍(yue)(pulse skipping)模(mo)(mo)式(shi)運行(xing)。在(zai)(zai)脈沖(chong)跳躍(yue)模(mo)(mo)式(shi)中(zhong)，PWM頻率異步變化。目(mu)前開(kai)(kai)(kai)發的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)IC，可(ke)(ke)以(yi)(yi)在(zai)(zai)使用(yong)開(kai)(kai)(kai)關充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)時提供高(gao)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)，且對系統的(de)(de)(de)(de)熱影(ying)響(xiang)非常小，而在(zai)(zai)低(di)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模(mo)(mo)式(shi)下切換到線(xian)性(xing)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)，以(yi)(yi)減(jian)少(shao)噪聲(sheng)。這種可(ke)(ke)提供線(xian)性(xing)模(mo)(mo)式(shi)的(de)(de)(de)(de)PWM開(kai)(kai)(kai)關模(mo)(mo)式(shi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)可(ke)(ke)以(yi)(yi)在(zai)(zai)全恒(heng)流(liu)(liu)(liu)(快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian))條件下實現高(gao)效率。開(kai)(kai)(kai)關充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)(qi)(qi)可(ke)(ke)利用(yong)PWM開(kai)(kai)(kai)關穩壓(ya)器(qi)(qi)(qi)(qi)控制高(gao)達(da)2A的(de)(de)(de)(de)恒(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。當電(dian)(dian)(dian)(dian)(dian)(dian)池處(chu)于(yu)預(yu)處(chu)理過(guo)程以(yi)(yi)及(ji)恒(heng)壓(ya)尖峰(taper)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模(mo)(mo)式(shi)快結束(shu)時，設(she)備會自動轉換到線(xian)形模(mo)(mo)式(shi)，以(yi)(yi)降低(di)噪聲(sheng)，并利用(yong)開(kai)(kai)(kai)關模(mo)(mo)式(shi)加快充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。一旦充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)值低(di)于(yu)300mA，線(xian)性(xing)模(mo)(mo)式(shi)會完全啟動，開(kai)(kai)(kai)關轉換器(qi)(qi)(qi)(qi)產生的(de)(de)(de)(de)噪聲(sheng)就會消除。

　　 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(jie)決方案，它的充(chong)電(dian)電(dian)流高(gao)達1A，具備先進的電(dian)充(chong)滿顯示功(gong)能，可(ke)以實(shi)現(xian)全程充(chong)電(dian)系統監(jian)(jian)控。符合USB標準的100mA/500mA充(chong)電(dian)電(dian)流設置有助于實(shi)現(xian)可(ke)編程預充(chong)電(dian)和快速充(chong)電(dian)。許多(duo)產品還具備電(dian)池溫度監(jian)(jian)測功(gong)能，以確保安全充(chong)電(dian)。

　　Intersil等公司正在開(kai)(kai)發新一代充(chong)電(dian)(dian)器(qi)(qi)IC技(ji)術。這些完全集成的解決方案(an)非常適合緊湊型應(ying)(ying)用(yong)，還(huan)能(neng)(neng)(neng)為高(gao)功率應(ying)(ying)用(yong)提供(gong)充(chong)電(dian)(dian)控制功能(neng)(neng)(neng)。目前(qian)，充(chong)電(dian)(dian)電(dian)(dian)壓精度(du)能(neng)(neng)(neng)達(da)到0.5%，較前(qian)幾年的1%有(you)很大改(gai)善(shan)。開(kai)(kai)關頻率可達(da)3MHz，而(er)且新型開(kai)(kai)關充(chong)電(dian)(dian)器(qi)(qi)可提供(gong)高(gao)達(da)2A的充(chong)電(dian)(dian)電(dian)(dian)流，最新的一個應(ying)(ying)用(yong)實(shi)例(li)是ISL9220，它適用(yong)于一節和兩節鋰(li)離子電(dian)(dian)池應(ying)(ying)用(yong)。

　　另外，新設(she)計(ji)還可以(yi)(yi)限(xian)制泄漏(lou)，目前在(zai)沒有加上輸入功率時(shi)，典型(xing)的泄漏(lou)電流已低于(yu)(yu)0.5uA。而且這些改進(jin)還可以(yi)(yi)用于(yu)(yu)更小的封裝，如4mm×4mm QFN或2mm×2mm CSP，以(yi)(yi)節省(sheng)手(shou)持式設(she)備(bei)的設(she)計(ji)空(kong)間(jian)。

　　最新的電池充電器IC還能(neng)夠監視輸(shu)入電(dian)(dian)壓、電(dian)(dian)池電(dian)(dian)壓和充(chong)電(dian)(dian)電(dian)(dian)流。當三個參(can)數(shu)中(zhong)任意一個超(chao)出特定限額時(shi)，該IC就(jiu)會關閉內部(bu)N溝道(dao)MOSFET，使充(chong)電(dian)(dian)系統(tong)停止對(dui)電(dian)(dian)池充(chong)電(dian)(dian)。利用這些(xie)重要的器件可以靈活地(di)提(ti)高(gao)效率，這對(dui)持續增長、功能(neng)不(bu)斷擴充(chong)的移動、手持式(shi)產品(pin)是(shi)至(zhi)關重要的。