電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流大(da)于電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)容量的(de)(de)20 隨著當今數碼電(dian)(dian)(dian)(dian)(dian)(dian)子產品功能的(de)(de)不(bu)斷增加，LCD屏幕(mu)越(yue)(yue)(yue)來越(yue)(yue)(yue)大(da)，以(yi)及不(bu)斷增強的(de)(de)多(duo)媒體視(shi)屏功能，市面上鋰離(li)子/聚合(he)物電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)容量也(ye)做得越(yue)(yue)(yue)來越(yue)(yue)(yue)大(da)。與此同(tong)時(shi)，消費(fei)者對(dui)縮短大(da)容量電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)充電(dian)(dian)(dian)(dian)(dian)(dian)時(shi)間提出(chu)了期望。為(wei)了能更快速有效地對(dui)這些(xie)大(da)容量電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)進行(xing)充電(dian)(dian)(dian)(dian)(dian)(dian)，以(yi)滿(man)足消費(fei)者不(bu)斷增長(chang)的(de)(de)需求，無(wu)錫(xi)芯朋微電(dian)(dian)(dian)(dian)(dian)(dian)子推(tui)出(chu)了大(da)電(dian)(dian)(dian)(dian)(dian)(dian)流鋰離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)(dian)(dian)芯片AP5056。

　　AP5056是可(ke)以(yi)對單節(jie)鋰離子或鋰聚(ju)合物可(ke)充電(dian)電(dian)池進行恒(heng)流(liu)/恒(heng)壓充電(dian)的(de)充電(dian)器(qi)(qi)電(dian)路(lu)。器(qi)(qi)件內(nei)部(bu)采(cai)用PMOSFET架構(gou)，應用時不需要(yao)外部(bu)另(ling)加阻流(liu)二(er)極管。熱反饋電(dian)路(lu)可(ke)以(yi)自動調節(jie)充電(dian)電(dian)流(liu)，使器(qi)(qi)件在功耗比較大(da)或者環境溫(wen)度(du)比較高的(de)情況下(xia)將芯(xin)片溫(wen)度(du)控(kong)制在安全范(fan)圍(wei)內(nei)。

　　AP5056只(zhi)需要(yao)極少的外圍元器件，可(ke)以適(shi)應(ying)USB 電(dian)(dian)(dian)(dian)源和適(shi)配(pei)器電(dian)(dian)(dian)(dian)源工作(zuo)，非常適(shi)用(yong)于(yu)便攜式應(ying)用(yong)的領域。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)輸出(chu)電(dian)(dian)(dian)(dian)壓(ya)為4.2V，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流的大小可(ke)以通過(guo)一個外部(bu)電(dian)(dian)(dian)(dian)阻(zu)設置。在恒壓(ya)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階(jie)段(duan)中，當充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流降(jiang)至設定值(zhi)1/10 時，AP5056將終止充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)循環。

　　當輸入(ru)電(dian)(dian)(dian)(dian)壓(交(jiao)流(liu)適(shi)配(pei)器或者(zhe)USB電(dian)(dian)(dian)(dian)源)掉電(dian)(dian)(dian)(dian)時，AP5056自動(dong)進入(ru)低功耗(hao)的(de)睡眠(mian)模式，此時電(dian)(dian)(dian)(dian)池的(de)電(dian)(dian)(dian)(dian)流(liu)消(xiao)耗(hao)小于2微安。其它功能(neng)包括(kuo)輸入(ru)電(dian)(dian)(dian)(dian)壓過(guo)低鎖存(cun)、芯片使能(neng)輸入(ru)、自動(dong)再充電(dian)(dian)(dian)(dian)、電(dian)(dian)(dian)(dian)池溫度監控以及狀態指示(shi)等功能(neng)。

　　充(chong)(chong)電(dian)(dian)過程：AP5056在整(zheng)個電(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)過程中有四種(zhong)基(ji)本(ben)充(chong)(chong)電(dian)(dian)模式：涓流充(chong)(chong)電(dian)(dian)、恒流充(chong)(chong)電(dian)(dian)、恒壓充(chong)(chong)電(dian)(dian)和充(chong)(chong)電(dian)(dian)完成與(yu)再充(chong)(chong)電(dian)(dian)。

　　涓(juan)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)：充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)開始(shi)前，AP5056先檢查(cha)輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)源，當輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)源大于最(zui)小工作電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)或(huo)欠壓(ya)鎖定(ding)閾值，并且芯片(pian)使(shi)能端接高電(dian)(dian)(dian)(dian)(dian)(dian)平(ping)時，AP5056開始(shi)對電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。AP5056先檢查(cha)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的狀態(tai)。如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)高于3V，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器則(ze)進(jin)入(ru)恒(heng)(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)；而如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)低于3V時，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器則(ze)進(jin)入(ru)涓(juan)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)模式。涓(juan)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)是恒(heng)(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)的十分之(zhi)一(yi)(還是以恒(heng)(heng)定(ding)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)為(wei)(wei)1A舉(ju)例(li)，則(ze)涓(juan)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)為(wei)(wei)100mA)，涓(juan)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)一(yi)直保(bao)持延續到AP5056芯片(pian)探(tan)測(ce)到電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達到3V后(hou)結束，之(zhi)后(hou)進(jin)入(ru)恒(heng)(heng)流(liu)(liu)(liu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)階段。

　　圖2：AP5056封裝(zhuang)。

　　恒流充電(dian)：恒流充電(dian)模式(shi)中，充電(dian)電(dian)流由(you)PROG腳(jiao)與GND間的(de)電(dian)阻RPROG確定。(參(can)見下文“可編程的(de)充電(dian)電(dian)流”)

　　IBAT = (VPROG/ RPROG)?1000 (VPROG的典型值(zhi)為1V)

　　AP5056進入恒流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模(mo)式中后，將(jiang)一直(zhi)按(an)設定的電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)值保持充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)，直(zhi)到(dao)電(dian)(dian)(dian)(dian)(dian)池慢慢到(dao)達(da)電(dian)(dian)(dian)(dian)(dian)壓調節點4.2V，轉(zhuan)(zhuan)而(er)進入恒壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。恒壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)：在電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓慢慢接(jie)近4.2V時，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器就漸漸轉(zhuan)(zhuan)為恒壓充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。此時原(yuan)先的恒流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)也(ye)慢慢減小，并隨(sui)著電(dian)(dian)(dian)(dian)(dian)池容(rong)量越來越接(jie)近最大容(rong)量而(er)急劇(ju)下(xia)降。 充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)完成與再充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)：當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)被探測(ce)到(dao)減小至恒流(liu)(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)的10%后，充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器終止向電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)，進入低功耗的待機(ji)模(mo)式。 在待機(ji)模(mo)式下(xia)，AP5056會繼(ji)續(xu)檢測(ce)電(dian)(dian)(dian)(dian)(dian)池端的電(dian)(dian)(dian)(dian)(dian)壓，如(ru)果(guo)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓降到(dao)4.05V以下(xia)，則(ze)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器將(jiang)再次向電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。

　　可編程的(de)充電電流：AP5056的(de)充電電流由連(lian)接在PROG腳與GND之間(jian)RPROG電阻來確定，計算公式如下：

　　IBAT = (VPROG/ RPROG)?1000 (VPROG的(de)典(dian)型值為(wei)1V)

　　例如，客戶需要得到一個1A的(de)充電電流的(de)話，根據公式得到

　　1A = (1/ RPROG)?1000，解方程式得VPROG = 1000Ω，即VPROG = 1KΩ

　　圖3顯示了RPROG為1K和2K時，不(bu)同的(de)(de)電(dian)(dian)源輸(shu)入Vcc 與(yu)充(chong)電(dian)(dian)電(dian)(dian)流Ibat之間(jian)的(de)(de)關(guan)系圖，可以看到充(chong)電(dian)(dian)輸(shu)出電(dian)(dian)流基本沒有很(hen)大變化(hua)，只(zhi)與(yu)RPROG的(de)(de)設定值有關(guan)系。

　　圖(tu)3：電(dian)源(yuan)輸入Vcc VS 充電(dian)電(dian)流Ibat。

　　典型應用電路

　　圖4給(gei)出的(de)是典型的(de)應(ying)用電(dian)(dian)路(lu)，電(dian)(dian)路(lu)中R1, R2由NTC熱敏電(dian)(dian)阻(zu)(zu)值來確(que)定。設(she)熱敏電(dian)(dian)阻(zu)(zu)在最低工(gong)作(zuo)溫(wen)度時(shi)的(de)電(dian)(dian)阻(zu)(zu)為RTL，在最高工(gong)作(zuo)溫(wen)度時(shi)的(de)電(dian)(dian)阻(zu)(zu)為RTH(RTL與RTH的(de)數(shu)據可查電(dian)(dian)池廠(chang)方數(shu)據或做實驗(yan)得(de)到)，則R1，R2的(de)阻(zu)(zu)值分別為：

　　圖4：AP5056應用電(dian)路。

　　如果用(yong)戶只(zhi)關心高溫保護，而不用(yong)關心低溫保護，則可將R2去掉(diao)，只(zhi)保留R1，這時R1的(de)計算公式變為：

　　直流適配器與USB組合的(de)方案

　當充(chong)電(dian)(dian)(dian)器(qi)需要直流(liu)(liu)適(shi)配(pei)器(qi)與USB充(chong)電(dian)(dian)(dian)兩者都能(neng)用(yong)時(shi)，可采用(yong)圖5所示的方案。方案中，假如使用(yong)USB口進行(xing)供電(dian)(dian)(dian)的話，MOS-P門(men)極(ji)接地(di)，USB電(dian)(dian)(dian)源(yuan)通(tong)過MOS-P導(dao)通(tong)至VCC，同時(shi)MOS-N處于(yu)(yu)關(guan)斷狀(zhuang)態，PROG上(shang)(shang)的編(bian)程電(dian)(dian)(dian)阻為(wei)(wei)2K，即(ji)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)設定(ding)為(wei)(wei)500mA，這(zhe)樣(yang)可防止USB接口被(bei)充(chong)電(dian)(dian)(dian)器(qi)拉(la)死；而(er)當采用(yong)5V直流(liu)(liu)適(shi)配(pei)器(qi)的時(shi)候，適(shi)配(pei)器(qi)電(dian)(dian)(dian)流(liu)(liu)通(tong)過肖特(te)基二極(ji)管(guan)加至VCC腳，MOS-P由于(yu)(yu)門(men)極(ji)為(wei)(wei)高電(dian)(dian)(dian)平(ping)而(er)被(bei)截止，不會對USB口產生影(ying)響。同時(shi)MOS-N由于(yu)(yu)門(men)極(ji)為(wei)(wei)高電(dian)(dian)(dian)平(ping)而(er)導(dao)通(tong)，此時(shi)PROG腳上(shang)(shang)的編(bian)程電(dian)(dian)(dian)阻相當于(yu)(yu)1K(2個2K電(dian)(dian)(dian)阻并聯)，即(ji)設定(ding)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)為(wei)(wei)1A，來對鋰離子(zi)電(dian)(dian)(dian)池進行(xing)快速(su)充(chong)電(dian)(dian)(dian)。

　　圖5：交流適配器與USB組合的方案。

　　芯片熱保護功能

　　利用晶體管PN結的(de)(de)導通電(dian)壓隨溫(wen)(wen)度(du)(du)(du)升(sheng)高而降低，而其(qi)變化值隨溫(wen)(wen)度(du)(du)(du)的(de)(de)升(sheng)高而增加的(de)(de)特性，AP5056設(she)計了(le)集成于芯片(pian)內(nei)部(bu)的(de)(de)過熱(re)保護(hu)功(gong)(gong)能(neng)。當內(nei)部(bu)溫(wen)(wen)度(du)(du)(du)傳感器升(sheng)至約(yue)125℃以(yi)上時，內(nei)部(bu)的(de)(de)熱(re)保護(hu)電(dian)路將自動(dong)減小充(chong)電(dian)電(dian)流(liu)(liu)的(de)(de)電(dian)流(liu)(liu)值，隨著溫(wen)(wen)度(du)(du)(du)的(de)(de)不斷升(sheng)高，當溫(wen)(wen)度(du)(du)(du)達到145℃的(de)(de)時候，則(ze)可(ke)完全(quan)關閉充(chong)電(dian)電(dian)流(liu)(liu)。該功(gong)(gong)能(neng)可(ke)以(yi)讓(rang)用戶放心使用最大功(gong)(gong)率的(de)(de)充(chong)電(dian)電(dian)流(liu)(liu)而無需擔心芯片(pian)被(bei)損壞。

　　充電狀態指示

　　AP5056有(you)CHRG和STDBY兩個狀(zhuang)態(tai)(tai)輸出指示。當充(chong)電(dian)器處于(yu)充(chong)電(dian)狀(zhuang)態(tai)(tai)時，CHRG置低電(dian)平，STDBY輸出高(gao)阻(zu)態(tai)(tai)；當電(dian)池(chi)處于(yu)充(chong)滿狀(zhuang)態(tai)(tai)時，CHRG變為高(gao)阻(zu)態(tai)(tai)，STDBY被拉為低電(dian)平。

　　如(ru)果不(bu)需(xu)要用(yong)到(dao)狀態(tai)指示功能，可以(yi)將不(bu)用(yong)的相(xiang)應的狀態(tai)輸出指示腳接地(di)。

　　指示燈狀態

　　布板的注意事項

　　AP5056采用(yong)SOP8-PP封裝(zhuang)，芯(xin)片底部帶有(you)散(san)(san)熱(re)(re)(re)(re)片，以便于(yu)將(jiang)(jiang)(jiang)芯(xin)片工作(zuo)時(shi)產生(sheng)的(de)(de)熱(re)(re)(re)(re)量通過散(san)(san)熱(re)(re)(re)(re)片發散(san)(san)出去，因此，為(wei)了達到較好(hao)的(de)(de)散(san)(san)熱(re)(re)(re)(re)效果(guo)，散(san)(san)熱(re)(re)(re)(re)片下(xia)的(de)(de)PC板銅箔(bo)面(mian)積(ji)要(yao)盡(jin)可能的(de)(de)寬(kuan)闊，并(bing)將(jiang)(jiang)(jiang)之延伸至外(wai)面(mian)更(geng)大，更(geng)寬(kuan)的(de)(de)銅箔(bo)面(mian)積(ji)，而且需(xu)將(jiang)(jiang)(jiang)散(san)(san)熱(re)(re)(re)(re)片與散(san)(san), 熱(re)(re)(re)(re)片下(xia)的(de)(de)銅箔(bo)用(yong)焊(han)錫焊(han)接在一起，以增加熱(re)(re)(re)(re)的(de)(de)傳(chuan)導性；此外(wai)，利用(yong)多個通孔將(jiang)(jiang)(jiang)上層銅箔(bo)與下(xia)層銅箔(bo)連接起來能夠更(geng)有(you)效地拓展散(san)(san)熱(re)(re)(re)(re)面(mian)積(ji)，有(you)利于(yu)將(jiang)(jiang)(jiang)熱(re)(re)(re)(re)量散(san)(san)至周圍環境中，增加充電芯(xin)片的(de)(de)散(san)(san)熱(re)(re)(re)(re)效果(guo)(如圖(tu)6所示)。

　　圖6：AP5056布(bu)板示意(yi)圖。

　　在芯片(pian)散熱良好(hao)的情(qing)況下，AP5056可(ke)提(ti)供(gong)電(dian)路最大充電(dian)電(dian)流為1600MA，實驗中(zhong)，在室(shi)溫狀(zhuang)態(tai)下，充電(dian)電(dian)流設置(zhi)為1600MA，連(lian)(lian)續(xu)(xu)工作15分鐘，IC表(biao)面溫度為60℃；設置(zhi)為1000MA時(shi)，連(lian)(lian)續(xu)(xu)工作15分鐘，IC表(biao)面溫度為50℃。

％時：
充電時間（小時）＝電池容量（mAH）×1.1÷充電電流(mA)