現在，大多數手持式設備都采用了兩種電池充電器，一(yi)種是(shi)(shi)線性充(chong)電(dian)器(qi)，另一(yi)種是(shi)(shi)開(kai)關充(chong)電(dian)器(qi)。線性充(chong)電(dian)器(qi)已有較長的歷史，充(chong)電(dian)方式比(bi)較簡單有效，噪聲很小，且沒(mei)有太多外部(bu)元(yuan)件。但是(shi)(shi)，隨著便攜式設(she)備(bei)(bei)越(yue)來越(yue)復雜，新功能(neng)層出不窮，高容量(liang)電(dian)池的需(xu)求就(jiu)更加強烈。線形充(chong)電(dian)器(qi)的缺點(dian)是(shi)(shi)功耗太大，特別是(shi)(shi)在設(she)備(bei)(bei)邊充(chong)電(dian)邊使用的時候尤為(wei)明顯，此(ci)時產生(sheng)的熱(re)量(liang)可能(neng)損壞(huai)系統或電(dian)池。

　　可(ke)供選擇的(de)有開關(guan)充(chong)電(dian)(dian)器或開關(guan)模式電(dian)(dian)池充(chong)電(dian)(dian)器IC，它可(ke)以使用盡可(ke)能少的(de)電(dian)(dian)量，為(wei)電(dian)(dian)池提供更高(gao)的(de)電(dian)(dian)流。從過往經驗(yan)來(lai)看，這類(lei)IC一般會存在一些(xie)噪聲問題。此外(wai)，前幾代的(de)開關(guan)式充(chong)電(dian)(dian)器還需要(yao)一些(xie)外(wai)部(bu)元件。

　　然而，開關(guan)式電池(chi)拓撲結構的(de)(de)(de)優(you)(you)勢也是顯(xian)而易見(jian)。這些優(you)(you)勢包括更高的(de)(de)(de)效率和更低的(de)(de)(de)功(gong)耗，還(huan)有更短的(de)(de)(de)充電時間。此類裝置還(huan)能利用(yong)較高的(de)(de)(de)輸入電壓充電，使(shi)用(yong)成本較低的(de)(de)(de)非穩壓適配器。還(huan)可以提高來(lai)自限流(liu)電流(liu)源的(de)(de)(de)充電電流(liu)。

　　開(kai)關(guan)(guan)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)通常在輕(qing)負(fu)載運(yun)行時(shi)會(hui)(hui)產(chan)生(sheng)噪(zao)聲(sheng)，特別(bie)是在預(yu)處(chu)理過程(cheng)中。隨著噪(zao)聲(sheng)的減少，開(kai)關(guan)(guan)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)會(hui)(hui)進入脈沖跳(tiao)躍(pulse skipping)模(mo)式(shi)(shi)運(yun)行。在脈沖跳(tiao)躍模(mo)式(shi)(shi)中，PWM頻率異(yi)步變化。目前(qian)開(kai)發的電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)IC，可以(yi)(yi)(yi)在使(shi)用開(kai)關(guan)(guan)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)時(shi)提(ti)供高充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)，且(qie)對系(xi)統的熱(re)影響非常小，而在低(di)(di)電(dian)(dian)(dian)(dian)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)下(xia)切換到線性(xing)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)，以(yi)(yi)(yi)減少噪(zao)聲(sheng)。這種(zhong)可提(ti)供線性(xing)模(mo)式(shi)(shi)的PWM開(kai)關(guan)(guan)模(mo)式(shi)(shi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)可以(yi)(yi)(yi)在全(quan)恒(heng)流(liu)(快(kuai)速(su)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian))條(tiao)件(jian)下(xia)實現(xian)高效率。開(kai)關(guan)(guan)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器(qi)(qi)(qi)可利用PWM開(kai)關(guan)(guan)穩壓器(qi)(qi)(qi)控制高達(da)2A的恒(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。當(dang)電(dian)(dian)(dian)(dian)池處(chu)于(yu)預(yu)處(chu)理過程(cheng)以(yi)(yi)(yi)及恒(heng)壓尖峰(taper)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模(mo)式(shi)(shi)快(kuai)結束時(shi)，設備會(hui)(hui)自(zi)動轉換到線形模(mo)式(shi)(shi)，以(yi)(yi)(yi)降低(di)(di)噪(zao)聲(sheng)，并利用開(kai)關(guan)(guan)模(mo)式(shi)(shi)加快(kuai)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。一旦充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)值低(di)(di)于(yu)300mA，線性(xing)模(mo)式(shi)(shi)會(hui)(hui)完全(quan)啟動，開(kai)關(guan)(guan)轉換器(qi)(qi)(qi)產(chan)生(sheng)的噪(zao)聲(sheng)就會(hui)(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，它的(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流高達1A，具(ju)(ju)備(bei)先進的(de)電(dian)(dian)(dian)(dian)充(chong)(chong)(chong)滿顯示功(gong)能，可(ke)(ke)以實現(xian)全(quan)程(cheng)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)系統監(jian)控(kong)。符合USB標準的(de)100mA/500mA充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流設(she)置有助(zhu)于實現(xian)可(ke)(ke)編(bian)程(cheng)預充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)和快速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。許多產(chan)品還具(ju)(ju)備(bei)電(dian)(dian)(dian)(dian)池溫度監(jian)測功(gong)能，以確(que)保(bao)安全(quan)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。

　　Intersil等公司正在開發新(xin)一代充電(dian)(dian)器IC技術(shu)。這些完全集成的解決方(fang)案非常適合緊湊型(xing)應(ying)用(yong)(yong)，還能為高功率應(ying)用(yong)(yong)提(ti)供充電(dian)(dian)控制功能。目前，充電(dian)(dian)電(dian)(dian)壓精(jing)度能達(da)到(dao)0.5%，較前幾(ji)年(nian)的1%有很大改善。開關(guan)頻率可達(da)3MHz，而且新(xin)型(xing)開關(guan)充電(dian)(dian)器可提(ti)供高達(da)2A的充電(dian)(dian)電(dian)(dian)流(liu)，最(zui)新(xin)的一個(ge)應(ying)用(yong)(yong)實(shi)例是ISL9220，它(ta)適用(yong)(yong)于(yu)一節和兩節鋰離子電(dian)(dian)池應(ying)用(yong)(yong)。

　　另(ling)外，新設(she)計(ji)還可(ke)以限制泄漏，目前在沒(mei)有加上(shang)輸(shu)入功(gong)率(lv)時，典型(xing)的(de)泄漏電流已低于0.5uA。而且這些改進還可(ke)以用于更(geng)小(xiao)的(de)封(feng)裝，如4mm×4mm QFN或2mm×2mm CSP，以節省(sheng)手持式設(she)備的(de)設(she)計(ji)空間(jian)。

　　最新的電池充電器IC還能(neng)(neng)夠監視輸入電(dian)壓(ya)、電(dian)池(chi)電(dian)壓(ya)和充(chong)電(dian)電(dian)流。當(dang)三(san)個參數中任意一個超出(chu)特定(ding)限(xian)額時，該IC就會關閉內部N溝道MOSFET，使充(chong)電(dian)系統停止對電(dian)池(chi)充(chong)電(dian)。利用這些重要的(de)器件可以靈活(huo)地提高效率，這對持續增長、功能(neng)(neng)不斷擴充(chong)的(de)移動、手持式產品是至關重要的(de)。