電(dian)(dian)子(zi)技(ji)(ji)術(shu)是十(shi)九世紀末、二(er)十(shi)世紀初開(kai)始發展(zhan)起(qi)來的新興技(ji)(ji)術(shu)，二(er)十(shi)世紀發展(zhan)最迅(xun)速，應(ying)用(yong)最廣(guang)泛，成(cheng)為(wei)近代科學技(ji)(ji)術(shu)發展(zhan)的一(yi)(yi)個重要標(biao)志。 第一(yi)(yi)代電(dian)(dian)子(zi)產品以電(dian)(dian)子(zi)管為(wei)核心。四(si)十(shi)年代末世界(jie)上(shang)(shang)誕生了(le)第一(yi)(yi)只半(ban)導體三極(ji)管，它以小巧、輕便(bian)、省電(dian)(dian)、壽命長等(deng)特點，很(hen)快地被(bei)各國應(ying)用(yong)起(qi)來，在很(hen)大(da)范圍內取(qu)代了(le)電(dian)(dian)子(zi)管。五(wu)十(shi)年代末期(qi)，世界(jie)上(shang)(shang)出現(xian)了(le)第一(yi)(yi)塊集(ji)成(cheng)電(dian)(dian)路(lu)(lu)，它把(ba)許(xu)多(duo)晶體管等(deng)電(dian)(dian)子(zi)元件集(ji)成(cheng)在一(yi)(yi)塊硅芯片上(shang)(shang)，使電(dian)(dian)子(zi)產品向更小型化發展(zhan)。集(ji)成(cheng)電(dian)(dian)路(lu)(lu)從小規模集(ji)成(cheng)電(dian)(dian)路(lu)(lu)迅(xun)速發展(zhan)到大(da)規模集(ji)成(cheng)電(dian)(dian)路(lu)(lu)和超大(da)規模集(ji)成(cheng)電(dian)(dian)路(lu)(lu)，從而使電(dian)(dian)子(zi)產品向著高效能(neng)低消耗(hao)、高精度(du)、高穩(wen)定(ding)、智能(neng)化的方向發展(zhan)。

小型便攜式電子產品采用的鋰離子電池或鋰聚合物電池的容量較小，大部分在400~1000mAh范圍內，與之配套的充電器的最大充電電流為450~1000mAh.由于電流不大，一般采用線性充電器。鋰(li)(li)離(li)(li)子(zi)(zi)電池(chi)(chi)的(de)不足之處在于(yu)對(dui)充(chong)電器要(yao)求比較苛刻，需(xu)要(yao)保護電路。鋰(li)(li)離(li)(li)子(zi)(zi)電池(chi)(chi)要(yao)求的(de)充(chong)電方式是(shi)恒流(liu)恒壓(ya)(ya)方式，為(wei)有效利用電池(chi)(chi)容量(liang)，需(xu)將(jiang)鋰(li)(li)離(li)(li)子(zi)(zi)電池(chi)(chi)充(chong)電至最大電壓(ya)(ya)，但是(shi)過壓(ya)(ya)充(chong)電會造(zao)成(cheng)電池(chi)(chi)損壞，這就要(yao)求較高(gao)的(de)控制精度(du)。另外，對(dui)于(yu)電壓(ya)(ya)過低的(de)電池(chi)(chi)需(xu)要(yao)進行預充(chong)，充(chong)電器最好帶有熱保護和(he)時(shi)間(jian)保護，為(wei)電池(chi)(chi)提供附加保護。因此，安全有效的(de)鋰(li)(li)離(li)(li)子(zi)(zi)電池(chi)(chi)充(chong)電器對(dui)于(yu)鋰(li)(li)離(li)(li)子(zi)(zi)電池(chi)(chi)來說(shuo)就是(shi)必須而且(qie)是(shi)必要(yao)的(de)。

鋰離子電池充電器外接限流型充電電源和P溝道場效應管，可以對單節鋰離子電池進行安全有效的快充，其最大特點是在不使用電感的情況下仍能做到很低的功率耗散，采用8腳μMAX封裝。充電控制精度達0.75%,可以實現預充電，具有過壓保護和溫度保護功能，最長充電時間限制為鋰離子電池提供二次保護，鋰離子電池充電器的(de)(de)浮充(chong)(chong)(chong)(chong)方式(shi)(shi)能(neng)(neng)夠(gou)使(shi)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)容量充(chong)(chong)(chong)(chong)至最(zui)大(da)。當(dang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源和電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)在正(zheng)常的(de)(de)工作溫度(du)范圍(wei)內時(shi)(shi)，插入電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)將啟動(dong)一次充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)過(guo)程;充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)結(jie)束的(de)(de)條件是(shi)平均的(de)(de)脈沖充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流達(da)到(dao)快充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)流的(de)(de)1%,或(huo)時(shi)(shi)間超出片上預置(zhi)的(de)(de)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)時(shi)(shi)間。鋰離子(zi)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器能(neng)(neng)夠(gou)自動(dong)檢測(ce)(ce)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源，沒(mei)有電(dian)(dian)(dian)(dian)源時(shi)(shi)自動(dong)關斷(duan)以減少電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的(de)(de)漏電(dian)(dian)(dian)(dian)。啟動(dong)快充(chong)(chong)(chong)(chong)后(hou)打開外接的(de)(de)P型(xing)場效(xiao)(xiao)應(ying)管，當(dang)檢測(ce)(ce)到(dao)電(dian)(dian)(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)(dian)(dian)壓達(da)到(dao)設定的(de)(de)門限時(shi)(shi)進(jin)入脈沖充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)方式(shi)(shi)，P溝道場效(xiao)(xiao)應(ying)管打開的(de)(de)時(shi)(shi)間會越(yue)來(lai)越(yue)短，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)結(jie)束時(shi)(shi)，LED指(zhi)示(shi)燈(deng)將會按(an)12%的(de)(de)周期閃爍。

近年(nian)來(lai)，一些(xie)用(yong)(yong)電量(liang)(liang)稍大的便攜(xie)式(shi)電子(zi)產品(如(ru)便攜(xie)式(shi)DVD、礦燈、攝像機、便攜(xie)式(shi)測量(liang)(liang)儀器、小型(xing)電動工具等(deng))往往采用(yong)(yong)1500mAh到5400mAh容(rong)量(liang)(liang)的鋰(li)離子(zi)電池。若采用(yong)(yong)500~1000mA充電電流充電器充電，則充電時間太長(chang)。

有人提出：能否在1A線性充(chong)電(dian)(dian)(dian)器電(dian)(dian)(dian)路(lu)中(zhong)加一(yi)(yi)個擴(kuo)流(liu)電(dian)(dian)(dian)路(lu)，使充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)擴(kuo)大到2~2.5A,解決(jue)3000~5400mAh容量鋰離子電(dian)(dian)(dian)池的充(chong)電(dian)(dian)(dian)問題(ti)。如果(guo)擴(kuo)流(liu)的充(chong)電(dian)(dian)(dian)器性能不(bu)錯、電(dian)(dian)(dian)路(lu)簡單、成本不(bu)高，這是個好主意。筆者就按這一(yi)(yi)思路(lu)設計一(yi)(yi)個擴(kuo)流(liu)電(dian)(dian)(dian)路(lu)。這電(dian)(dian)(dian)路(lu)采用型號為CN3056的1A線性充(chong)電(dian)(dian)(dian)器為基(ji)礎，另外加上擴(kuo)流(liu)電(dian)(dian)(dian)路(lu)及控(kong)制(zhi)電(dian)(dian)(dian)路(lu)組成。

CN3056簡介

CN3056組成(cheng)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器按(an)恒流(liu)(liu)(liu)、恒壓(ya)模(mo)式充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)，若(ruo)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)<3V,則(ze)有小電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)預充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模(mo)式;充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)可設定，最(zui)大充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)為1A;精(jing)電(dian)(dian)(dian)(dian)(dian)密(mi)度4.2V±1%、有熱(re)調(diao)節、欠(qian)壓(ya)鎖(suo)存及(ji)電(dian)(dian)(dian)(dian)(dian)池溫度檢測、超溫保護及(ji)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)狀態和(he)溫度超差指示(shi)功(gong)能;10引腳(jiao)小尺寸(cun)DFN封裝(3mm×3mm)。CN3056是可以對單節鋰離(li)子或者(zhe)鋰-聚合物電(dian)(dian)(dian)(dian)(dian)池進行恒流(liu)(liu)(liu)/恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器電(dian)(dian)(dian)(dian)(dian)路(lu)。該器件內部包括功(gong)率晶體管，應用時不(bu)需要外(wai)部的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)檢測電(dian)(dian)(dian)(dian)(dian)阻(zu)和(he)阻(zu)流(liu)(liu)(liu)二(er)極管

若(ruo)充(chong)電(dian)(dian)(dian)率在0.5~1C之間、電(dian)(dian)(dian)池(chi)的溫(wen)度在0~45℃之間(室(shi)溫(wen)充(chong)電(dian)(dian)(dian))，則CN3056充(chong)電(dian)(dian)(dian)器(qi)電(dian)(dian)(dian)路中(zhong)可省去電(dian)(dian)(dian)池(chi)溫(wen)度檢測電(dian)(dian)(dian)路及(ji)電(dian)(dian)(dian)池(chi)超溫(wen)指示電(dian)(dian)(dian)路(引腳(jiao)TEMP及(ji)FAULT端接(jie)地(di))，電(dian)(dian)(dian)路如圖(tu)1所示。VIN是(shi)電(dian)(dian)(dian)源輸(shu)入(ru)端、CE是(shi)使能端，(高(gao)電(dian)(dian)(dian)平有效);RISET為(wei)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流ICH設定電(dian)(dian)(dian)阻，RISET(Ω)=1800(V)/ICH(A);CHRG為(wei)充(chong)電(dian)(dian)(dian)狀態信號輸(shu)出端：充(chong)電(dian)(dian)(dian)時此端為(wei)高(gao)電(dian)(dian)(dian)平，LED亮(liang);充(chong)電(dian)(dian)(dian)結束時此端為(wei)高(gao)阻抗，LED滅;電(dian)(dian)(dian)池(chi)未(wei)裝入(ru)或(huo)接(jie)觸不良，LED閃亮(liang)。