電(dian)(dian)子(zi)技術(shu)是(shi)十九(jiu)世紀末(mo)(mo)、二十世紀初開始(shi)發(fa)(fa)(fa)展起來的(de)新興技術(shu)，二十世紀發(fa)(fa)(fa)展最迅速(su)，應(ying)用最廣泛，成(cheng)(cheng)(cheng)(cheng)(cheng)為近(jin)代(dai)科學技術(shu)發(fa)(fa)(fa)展的(de)一(yi)(yi)(yi)(yi)個重要(yao)標(biao)志。 第一(yi)(yi)(yi)(yi)代(dai)電(dian)(dian)子(zi)產品以(yi)電(dian)(dian)子(zi)管為核心。四十年(nian)代(dai)末(mo)(mo)世界上(shang)誕生(sheng)了(le)第一(yi)(yi)(yi)(yi)只半導體三(san)極管，它以(yi)小(xiao)巧、輕便、省電(dian)(dian)、壽命長(chang)等特點，很快地被各(ge)國(guo)應(ying)用起來，在(zai)很大范(fan)圍內取代(dai)了(le)電(dian)(dian)子(zi)管。五十年(nian)代(dai)末(mo)(mo)期，世界上(shang)出現了(le)第一(yi)(yi)(yi)(yi)塊(kuai)集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)電(dian)(dian)路(lu)，它把許多(duo)晶體管等電(dian)(dian)子(zi)元件集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)在(zai)一(yi)(yi)(yi)(yi)塊(kuai)硅芯片上(shang)，使電(dian)(dian)子(zi)產品向更小(xiao)型化發(fa)(fa)(fa)展。集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)電(dian)(dian)路(lu)從(cong)小(xiao)規模集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)電(dian)(dian)路(lu)迅速(su)發(fa)(fa)(fa)展到(dao)大規模集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)電(dian)(dian)路(lu)和超大規模集(ji)成(cheng)(cheng)(cheng)(cheng)(cheng)電(dian)(dian)路(lu)，從(cong)而(er)使電(dian)(dian)子(zi)產品向著高(gao)效能低消(xiao)耗、高(gao)精度、高(gao)穩定、智能化的(de)方向發(fa)(fa)(fa)展。

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)離(li)子(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的不足(zu)之處在于對充(chong)電(dian)(dian)(dian)(dian)(dian)器要(yao)(yao)求比較苛刻，需要(yao)(yao)保(bao)護電(dian)(dian)(dian)(dian)(dian)路。鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)要(yao)(yao)求的充(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)式是恒流恒壓方(fang)式，為有(you)(you)效(xiao)利用電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)容(rong)量(liang)，需將鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)至最大電(dian)(dian)(dian)(dian)(dian)壓，但(dan)是過壓充(chong)電(dian)(dian)(dian)(dian)(dian)會造成電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)損壞，這就要(yao)(yao)求較高的控制精度。另外，對于電(dian)(dian)(dian)(dian)(dian)壓過低的電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)需要(yao)(yao)進(jin)行預充(chong)，充(chong)電(dian)(dian)(dian)(dian)(dian)器最好(hao)帶有(you)(you)熱保(bao)護和時間保(bao)護，為電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)提供附加保(bao)護。因(yin)此，安全有(you)(you)效(xiao)的鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)器對于鋰(li)離(li)子(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)來說就是必(bi)須(xu)而且是必(bi)要(yao)(yao)的。

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)浮充(chong)(chong)方式(shi)(shi)能(neng)夠使電(dian)(dian)(dian)(dian)池(chi)(chi)容量充(chong)(chong)至最(zui)大。當充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源和電(dian)(dian)(dian)(dian)池(chi)(chi)在正常的(de)工作溫度(du)范(fan)圍內時，插入(ru)電(dian)(dian)(dian)(dian)池(chi)(chi)將啟動(dong)一(yi)次充(chong)(chong)電(dian)(dian)(dian)(dian)過程;充(chong)(chong)電(dian)(dian)(dian)(dian)結束的(de)條(tiao)件是平均的(de)脈沖(chong)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流達到(dao)快充(chong)(chong)電(dian)(dian)(dian)(dian)流的(de)1%,或時間(jian)超(chao)出片(pian)上預置的(de)充(chong)(chong)電(dian)(dian)(dian)(dian)時間(jian)。鋰離子電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)器能(neng)夠自動(dong)檢測(ce)充(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)源，沒(mei)有(you)電(dian)(dian)(dian)(dian)源時自動(dong)關(guan)斷(duan)以減少(shao)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)漏電(dian)(dian)(dian)(dian)。啟動(dong)快充(chong)(chong)后(hou)打(da)開外接的(de)P型場效(xiao)應(ying)管(guan)，當檢測(ce)到(dao)電(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)壓達到(dao)設定(ding)的(de)門限時進入(ru)脈沖(chong)充(chong)(chong)電(dian)(dian)(dian)(dian)方式(shi)(shi)，P溝道場效(xiao)應(ying)管(guan)打(da)開的(de)時間(jian)會(hui)越來越短，充(chong)(chong)電(dian)(dian)(dian)(dian)結束時，LED指示燈將會(hui)按12%的(de)周期閃爍。

近(jin)年來，一些用電(dian)量稍大的便攜(xie)式電(dian)子(zi)產(chan)品(pin)(如便攜(xie)式DVD、礦燈(deng)、攝(she)像機、便攜(xie)式測量儀器(qi)、小型電(dian)動(dong)工具等)往(wang)(wang)往(wang)(wang)采(cai)用1500mAh到5400mAh容(rong)量的鋰離子(zi)電(dian)池。若(ruo)采(cai)用500~1000mA充電(dian)電(dian)流充電(dian)器(qi)充電(dian)，則充電(dian)時間太(tai)長。

有人提出：能(neng)否在1A線性(xing)充(chong)(chong)電(dian)器電(dian)路中加(jia)一(yi)(yi)個(ge)(ge)擴流(liu)(liu)電(dian)路，使充(chong)(chong)電(dian)電(dian)流(liu)(liu)擴大到2~2.5A,解決3000~5400mAh容量鋰(li)離子(zi)電(dian)池的充(chong)(chong)電(dian)問題。如果擴流(liu)(liu)的充(chong)(chong)電(dian)器性(xing)能(neng)不錯、電(dian)路簡單、成(cheng)本不高，這(zhe)是個(ge)(ge)好主意。筆者就按這(zhe)一(yi)(yi)思路設計一(yi)(yi)個(ge)(ge)擴流(liu)(liu)電(dian)路。這(zhe)電(dian)路采用型號為CN3056的1A線性(xing)充(chong)(chong)電(dian)器為基礎(chu)，另(ling)外加(jia)上擴流(liu)(liu)電(dian)路及控制電(dian)路組成(cheng)。

CN3056簡介

CN3056組成的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)器按恒(heng)流(liu)、恒(heng)壓(ya)模式充(chong)(chong)電(dian)(dian)(dian)，若充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)<3V,則有小(xiao)(xiao)電(dian)(dian)(dian)流(liu)預充(chong)(chong)電(dian)(dian)(dian)模式;充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)可設定，最大充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)為1A;精電(dian)(dian)(dian)密度(du)(du)4.2V±1%、有熱(re)調(diao)節(jie)、欠壓(ya)鎖存及電(dian)(dian)(dian)池(chi)溫度(du)(du)檢(jian)測、超溫保護及充(chong)(chong)電(dian)(dian)(dian)狀(zhuang)態和溫度(du)(du)超差指示(shi)功(gong)能(neng);10引腳小(xiao)(xiao)尺寸DFN封(feng)裝(zhuang)(3mm×3mm)。CN3056是(shi)可以(yi)對單節(jie)鋰(li)離(li)子或者鋰(li)-聚合(he)物電(dian)(dian)(dian)池(chi)進行恒(heng)流(liu)/恒(heng)壓(ya)充(chong)(chong)電(dian)(dian)(dian)的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)器電(dian)(dian)(dian)路。該器件內部(bu)包括功(gong)率晶體管(guan)，應用時不需要外部(bu)的(de)(de)(de)電(dian)(dian)(dian)流(liu)檢(jian)測電(dian)(dian)(dian)阻和阻流(liu)二極管(guan)

若充(chong)(chong)電(dian)率在0.5~1C之(zhi)間、電(dian)池的溫(wen)(wen)度在0~45℃之(zhi)間(室溫(wen)(wen)充(chong)(chong)電(dian))，則CN3056充(chong)(chong)電(dian)器電(dian)路中(zhong)可省去電(dian)池溫(wen)(wen)度檢(jian)測電(dian)路及電(dian)池超溫(wen)(wen)指示(shi)電(dian)路(引腳TEMP及FAULT端(duan)(duan)接地)，電(dian)路如圖(tu)1所示(shi)。VIN是(shi)電(dian)源輸(shu)入端(duan)(duan)、CE是(shi)使(shi)能端(duan)(duan)，(高(gao)(gao)電(dian)平有效);RISET為(wei)(wei)充(chong)(chong)電(dian)電(dian)流(liu)ICH設定(ding)電(dian)阻(zu)，RISET(Ω)=1800(V)/ICH(A);CHRG為(wei)(wei)充(chong)(chong)電(dian)狀態信號輸(shu)出端(duan)(duan)：充(chong)(chong)電(dian)時此(ci)端(duan)(duan)為(wei)(wei)高(gao)(gao)電(dian)平，LED亮;充(chong)(chong)電(dian)結束時此(ci)端(duan)(duan)為(wei)(wei)高(gao)(gao)阻(zu)抗，LED滅;電(dian)池未裝入或接觸不良，LED閃亮。