鋰(li)(li)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)是(shi)專(zhuan)門(men)用來(lai)為(wei)鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)。鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)對(dui)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)的(de)(de)(de)要(yao)求較(jiao)高，需(xu)(xu)要(yao)保護電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)，所 以(yi)鋰(li)(li)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)通常都(dou)有(you)較(jiao)高的(de)(de)(de)控制(zhi)精(jing)密度，能(neng)(neng)夠對(dui)鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)進行恒(heng)(heng)流(liu)恒(heng)(heng)壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)具有(you)較(jiao)高的(de)(de)(de)能(neng)(neng)量(liang)(liang)重量(liang)(liang)比和(he)能(neng)(neng)量(liang)(liang)體積比、無(wu)記憶(yi)效應、可(ke)重復充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)多(duo)次、使用壽(shou)命較(jiao)長、價(jia)格(ge)也越(yue)來(lai)越(yue)低(di)(di)。鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)這些特點促進了便攜(xie)式產品(pin)向更(geng)(geng)小更(geng)(geng)輕的(de)(de)(de)方(fang)(fang)向發展(zhan),使得(de)選(xuan)用單(dan)節鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)供(gong)(gong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)產品(pin)也越(yue)來(lai)越(yue)多(duo)。鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)不足之處(chu)在(zai)于對(dui)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)要(yao)求比較(jiao)苛刻,需(xu)(xu)要(yao)保護電(dian)(dian)(dian)(dian)(dian)路(lu)(lu)。鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)要(yao)求的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)方(fang)(fang)式是(shi)恒(heng)(heng)流(liu)恒(heng)(heng)壓方(fang)(fang)式,為(wei)有(you)效利用電(dian)(dian)(dian)(dian)(dian)池(chi)容量(liang)(liang),需(xu)(xu)將(jiang)鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)至(zhi)最(zui)大電(dian)(dian)(dian)(dian)(dian)壓,但是(shi)過(guo)壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)會造成(cheng)電(dian)(dian)(dian)(dian)(dian)池(chi)損(sun)壞,這就要(yao)求較(jiao)高的(de)(de)(de)控制(zhi)精(jing)度。另外,對(dui)于電(dian)(dian)(dian)(dian)(dian)壓過(guo)低(di)(di)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池(chi)需(xu)(xu)要(yao)進行預(yu)充(chong)(chong),充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)最(zui)好帶有(you)熱(re)保護和(he)時(shi)間保護,為(wei)電(dian)(dian)(dian)(dian)(dian)池(chi)提供(gong)(gong)附加保護。因(yin)此(ci)，安全有(you)效的(de)(de)(de)鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)(qi)對(dui)于鋰(li)(li)離(li)子(zi)(zi)(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)來(lai)說(shuo)就是(shi)必須(xu)而且是(shi)必要(yao)的(de)(de)(de)。

    鋰(li)電(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)器(qi)工作(zuo)原(yuan)理：鋰(li)離(li)子電(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)器(qi)外接限流型(xing)充(chong)電(dian)(dian)電(dian)(dian)源和(he)Ｐ溝道場效應管,可(ke)(ke)以(yi)(yi)對單(dan)節(jie)鋰(li)離(li)子電(dian)(dian)池(chi)(chi)進行安全有(you)效的快(kuai)充(chong),其最(zui)大(da)特點是在(zai)不(bu)使用電(dian)(dian)感的情況下仍能做到很低(di)的功率耗(hao)散,采用8腳μMAX封裝。充(chong)電(dian)(dian)控制精度(du)達0.75％,可(ke)(ke)以(yi)(yi)實現預充(chong)電(dian)(dian),具有(you)過壓保護(hu)和(he)溫度(du)保護(hu)功能,最(zui)長充(chong)電(dian)(dian)時(shi)間限制為(wei)鋰(li)離(li)子電(dian)(dian)池(chi)(chi)提供二次保護(hu),鋰(li)離(li)子電(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)器(qi)的浮(fu)充(chong)方式能夠(gou)使電(dian)(dian)池(chi)(chi)容(rong)量充(chong)至最(zui)大(da)。

　　當(dang)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)源和(he)電(dian)(dian)(dian)(dian)(dian)池(chi)在(zai)正常的(de)工作溫度范(fan)圍內時(shi),插入電(dian)(dian)(dian)(dian)(dian)池(chi)將啟(qi)動(dong)(dong)一(yi)次(ci)充電(dian)(dian)(dian)(dian)(dian)過程;充電(dian)(dian)(dian)(dian)(dian)結(jie)束(shu)的(de)條件是平(ping)均的(de)脈(mo)沖(chong)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)達(da)到(dao)快充電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)1％,或時(shi)間(jian)(jian)超(chao)出片(pian)上(shang)預置的(de)充電(dian)(dian)(dian)(dian)(dian)時(shi)間(jian)(jian)。鋰離子電(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)器能夠自(zi)動(dong)(dong)檢(jian)測充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)源,沒有電(dian)(dian)(dian)(dian)(dian)源時(shi)自(zi)動(dong)(dong)關斷以減(jian)少電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)漏(lou)電(dian)(dian)(dian)(dian)(dian)。啟(qi)動(dong)(dong)快充后打(da)開外接的(de)P型場效應(ying)管,當(dang)檢(jian)測到(dao)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓達(da)到(dao)設(she)定的(de)門限時(shi)進入脈(mo)沖(chong)充電(dian)(dian)(dian)(dian)(dian)方式,Ｐ溝道場效應(ying)管打(da)開的(de)時(shi)間(jian)(jian)會(hui)越(yue)來越(yue)短(duan),充電(dian)(dian)(dian)(dian)(dian)結(jie)束(shu)時(shi),LED指示燈(deng)將會(hui)按12％的(de)周期閃爍。

工作流程

　　鋰(li)離子電池(chi)充(chong)電器的(de)工作狀態流(liu)程圖如圖1所示(shi)。

　　（1）初始化充電(dian)周期(qi)

　　鋰(li)(li)離(li)子(zi)(zi)電(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)器(qi)檢測到電(dian)(dian)池(chi)(chi)(chi)和充(chong)電(dian)(dian)電(dian)(dian)源后(hou)將初始(shi)化充(chong)電(dian)(dian)周期,充(chong)電(dian)(dian)結束后(hou),如(ru)檢測到電(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)壓(ya)低于(yu)3.89V或THERM引腳電(dian)(dian)壓(ya)高于(yu)1.4V將重新充(chong)電(dian)(dian)。允許快(kuai)充(chong)的條(tiao)件是電(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)壓(ya)大(da)于(yu)2.5V且(qie)小于(yu)充(chong)電(dian)(dian)閾值電(dian)(dian)壓(ya)（默認值是4.2V）,而且(qie)溫度范圍為(wei)2.5°C～47.5°C,如(ru)果溫度范圍不符,鋰(li)(li)離(li)子(zi)(zi)電(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)器(qi)將處于(yu)等待狀態。電(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)壓(ya)低于(yu)2.5V時(shi),鋰(li)(li)離(li)子(zi)(zi)電(dian)(dian)池(chi)(chi)(chi)充(chong)電(dian)(dian)器(qi)用(yong)5mA的電(dian)(dian)流預充(chong),防(fang)止(zhi)深(shen)度放電(dian)(dian)的鋰(li)(li)離(li)子(zi)(zi)電(dian)(dian)池(chi)(chi)(chi)在快(kuai)充(chong)時(shi)被(bei)損壞甚至發生危險(xian)。

　　（2）快充過程

　　快(kuai)(kuai)(kuai)充(chong)開始后,鋰離子電(dian)池充(chong)電(dian)器打開外接的P溝道場效(xiao)應管,充(chong)電(dian)電(dian)流由(you)外部限流型(xing)充(chong)電(dian)電(dian)源決定(ding)。由(you)于P溝道場效(xiao)應管工(gong)作(zuo)在開關狀態,并非線性穩壓器,所以功耗(hao)極小,快(kuai)(kuai)(kuai)充(chong)結束的條(tiao)件是(shi)(shi)電(dian)池電(dian)壓達到閾值（由(you)ADJ引腳(jiao)調節(jie)）或充(chong)電(dian)時(shi)間達到預定(ding)的快(kuai)(kuai)(kuai)充(chong)時(shi)間或溫(wen)(wen)度超(chao)出安全范(fan)圍,溫(wen)(wen)度超(chao)出工(gong)作(zuo)范(fan)圍時(shi)快(kuai)(kuai)(kuai)充(chong)只是(shi)(shi)暫停,當溫(wen)(wen)度恢復后快(kuai)(kuai)(kuai)充(chong)將(jiang)持續進行(xing)。

　　（3）脈沖充電(dian)過程

　　多數情況下(xia)充電(dian)(dian)(dian)電(dian)(dian)(dian)池達(da)到(dao)閾(yu)值后便結(jie)束(shu)快充過(guo)程(cheng)(cheng)(cheng)而進入脈沖(chong)充電(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng),鋰(li)離子電(dian)(dian)(dian)池充電(dian)(dian)(dian)器每隔2ms檢測一次電(dian)(dian)(dian)池電(dian)(dian)(dian)壓,電(dian)(dian)(dian)池電(dian)(dian)(dian)壓小于閾(yu)值時(shi)(shi)(shi),外(wai)部(bu)P溝(gou)道(dao)場效(xiao)應(ying)管(guan)導通,電(dian)(dian)(dian)池電(dian)(dian)(dian)壓大(da)(da)于等于閾(yu)值時(shi)(shi)(shi),P溝(gou)道(dao)場效(xiao)應(ying)管(guan)斷開,脈沖(chong)充電(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng)接近結(jie)束(shu)時(shi)(shi)(shi),P溝(gou)道(dao)場效(xiao)應(ying)管(guan)的(de)斷開時(shi)(shi)(shi)間(jian)(jian)大(da)(da)大(da)(da)超過(guo)接通時(shi)(shi)(shi)間(jian)(jian),達(da)到(dao)TSEL管(guan)腳設置的(de)周期比（1／64,1／128,1／256）后脈沖(chong)充電(dian)(dian)(dian)過(guo)程(cheng)(cheng)(cheng)結(jie)束(shu)。

　　（4）充電(dian)狀態指示CHG

　　管(guan)腳CHG與管(guan)腳IN之間(jian)連接LED作為充(chong)電(dian)(dian)狀態(tai)(tai)指示燈,當(dang)(dang)沒(mei)有插入電(dian)(dian)池或電(dian)(dian)源沒(mei)有連接或電(dian)(dian)池電(dian)(dian)壓小于(yu)2.2V時(shi),CHG管(guan)腳是(shi)高阻態(tai)(tai),LED不亮(liang);當(dang)(dang)快充(chong)或脈沖充(chong)電(dian)(dian)時(shi),LED亮(liang),在初始化期間(jian)或時(shi)間(jian)超出預定時(shi)間(jian),LED按50％的周期閃(shan)爍;當(dang)(dang)充(chong)電(dian)(dian)狀態(tai)(tai)結束時(shi),LED按12％的周期閃(shan)爍。

典型應(ying)用及注意(yi)事項

  

典型應用電路圖

　　圖２是一個簡單的單節(jie)鋰離(li)子電池充電器,包括：LED顯示、熱(re)敏(min)電阻、電流反向(xiang)保(bao)護。

　　ADJ引腳通過10kΩ的電阻與內部(bu) 1.4V的精密(mi)基準源相連(lian)接(jie),當ADJ對地(di)沒有(you)連(lian)接(jie)電阻RADJ時(shi),電池充電電壓(ya)閾值為缺省值：VBR＝4.2V;

　　當需要自行設置充電(dian)閾值(zhi)(zhi)時,可在(zai)ADJ引(yin)腳(jiao)與(yu)GND間接一(yi)精度為(wei)1％的電(dian)阻(zu)RADJ,阻(zu)值(zhi)(zhi)由下(xia)式(shi)確定：

  

阻值

　　圖(tu)2電路中,充電閾(yu)值為(wei)(wei)4.1V,由(you)（１）式得(de)RADJ＝410kΩ,電阻(zu)精度為(wei)(wei)1％時,產生的系統誤差為(wei)(wei)：

  

系統誤差

　　TSEL管腳接(jie)(jie)(jie)BATT或(huo)ADJ或(huo)GND將得到不同的(de)快(kuai)充(chong)(chong)時(shi)間(jian)(jian)和完整(zheng)的(de)充(chong)(chong)電(dian)時(shi)間(jian)(jian)。TSEL管腳接(jie)(jie)(jie)BATT時(shi)快(kuai)充(chong)(chong)時(shi)間(jian)(jian)為55分(fen)鐘,全部(bu)充(chong)(chong)電(dian)時(shi)間(jian)(jian)為2.8小(xiao)時(shi)TSEL接(jie)(jie)(jie)ADJ時(shi)快(kuai)充(chong)(chong)時(shi)間(jian)(jian)為75分(fen)鐘,整(zheng)個充(chong)(chong)電(dian)時(shi)間(jian)(jian)為3.75小(xiao)時(shi),TSEL接(jie)(jie)(jie)GND時(shi)快(kuai)充(chong)(chong)時(shi)間(jian)(jian)沒(mei)有限制,整(zheng)個充(chong)(chong)電(dian)時(shi)間(jian)(jian)為6.25小(xiao)時(shi)。充(chong)(chong)電(dian)電(dian)流(liu)的(de)限制可以采用(yong)限流(liu)電(dian)阻(zu)的(de)方(fang)法解決。 

鋰電池充電器使(shi)用注意事(shi)項：

　　　　1.應使充(chong)(chong)電(dian)(dian)器的(de)工作(zuo)選(xuan)擇與被充(chong)(chong)電(dian)(dian)池一致。如果(guo)充(chong)(chong)電(dian)(dian)器工作(zuo)于鋰(li)電(dian)(dian)池狀(zhuang)(zhuang)態而去允(yun)鎳氫或鎳鎘電(dian)(dian)池，則電(dian)(dian)池充(chong)(chong)不滿，會大大減少工作(zuo)時間。如果(guo)充(chong)(chong)電(dian)(dian)器工作(zuo)于鎳電(dian)(dian)池狀(zhuang)(zhuang)態而去充(chong)(chong)鋰(li)離子電(dian)(dian)池，則鋰(li)電(dian)(dian)池被過充(chong)(chong)，將嚴重影響電(dian)(dian)池的(de)壽命。

　　2.要了解所(suo)用充(chong)(chong)電(dian)(dian)(dian)器充(chong)(chong)滿點亮(liang)(liang)時(shi)電(dian)(dian)(dian)池(chi)是否真的已充(chong)(chong)滿。有(you)些(xie)充(chong)(chong)電(dian)(dian)(dian)器見到充(chong)(chong)滿指示(shi)燈亮(liang)(liang)即(ji)可將鋰電(dian)(dian)(dian)池(chi)取下，有(you)些(xie)充(chong)(chong)電(dian)(dian)(dian)器要見到指示(shi)燈全亮(liang)(liang)才可將電(dian)(dian)(dian)池(chi)取下。