電(dian)(dian)電(dian)(dian)流大于電(dian)(dian)池容量(liang)的(de)20 隨著當今數碼(ma)電(dian)(dian)子(zi)產品功(gong)(gong)能(neng)的(de)不斷增(zeng)加，LCD屏幕越(yue)來越(yue)大，以(yi)及不斷增(zeng)強的(de)多媒體視屏功(gong)(gong)能(neng)，市面上鋰離(li)子(zi)/聚合物電(dian)(dian)池的(de)容量(liang)也做得(de)越(yue)來越(yue)大。與(yu)此(ci)同時，消費(fei)(fei)者(zhe)對縮短大容量(liang)電(dian)(dian)池的(de)充(chong)(chong)電(dian)(dian)時間提出了(le)期望。為了(le)能(neng)更快速有效(xiao)地對這些大容量(liang)電(dian)(dian)池進(jin)行(xing)充(chong)(chong)電(dian)(dian)，以(yi)滿足(zu)消費(fei)(fei)者(zhe)不斷增(zeng)長的(de)需求，無錫芯(xin)朋微電(dian)(dian)子(zi)推出了(le)大電(dian)(dian)流鋰離(li)子(zi)電(dian)(dian)池充(chong)(chong)電(dian)(dian)芯(xin)片(pian)AP5056。

　　AP5056是可以對單(dan)節鋰(li)離子或鋰(li)聚(ju)合(he)物可充電(dian)(dian)電(dian)(dian)池(chi)進行恒流/恒壓充電(dian)(dian)的充電(dian)(dian)器電(dian)(dian)路。器件內部采(cai)用(yong)(yong)PMOSFET架構，應(ying)用(yong)(yong)時(shi)不(bu)需要(yao)外部另加阻(zu)流二極(ji)管(guan)。熱(re)反饋電(dian)(dian)路可以自(zi)動調節充電(dian)(dian)電(dian)(dian)流，使器件在功耗比(bi)較(jiao)大(da)或者環境溫(wen)度(du)比(bi)較(jiao)高的情況(kuang)下將芯(xin)片溫(wen)度(du)控(kong)制在安全范圍內。

　　AP5056只需(xu)要(yao)極少的(de)外(wai)圍元器件(jian)，可以適應USB 電源和適配器電源工作，非常適用于(yu)便攜(xie)式應用的(de)領域。充電輸(shu)出電壓為4.2V，充電電流的(de)大小可以通過一個外(wai)部電阻(zu)設(she)(she)置。在恒(heng)壓充電階段中，當充電電流降至設(she)(she)定值(zhi)1/10 時，AP5056將(jiang)終(zhong)止充電循(xun)環。

　　當輸入電(dian)(dian)(dian)壓(ya)(交流(liu)適配(pei)器或者USB電(dian)(dian)(dian)源(yuan))掉電(dian)(dian)(dian)時，AP5056自動(dong)進入低(di)(di)功耗的睡眠模(mo)式，此時電(dian)(dian)(dian)池的電(dian)(dian)(dian)流(liu)消(xiao)耗小(xiao)于2微安。其它功能(neng)包(bao)括輸入電(dian)(dian)(dian)壓(ya)過低(di)(di)鎖存、芯(xin)片使能(neng)輸入、自動(dong)再充電(dian)(dian)(dian)、電(dian)(dian)(dian)池溫度(du)監(jian)控以及(ji)狀態指(zhi)示(shi)等功能(neng)。

　　充(chong)電(dian)(dian)過(guo)程：AP5056在整個電(dian)(dian)池(chi)充(chong)電(dian)(dian)過(guo)程中有四種基本充(chong)電(dian)(dian)模式：涓(juan)流充(chong)電(dian)(dian)、恒流充(chong)電(dian)(dian)、恒壓充(chong)電(dian)(dian)和充(chong)電(dian)(dian)完成與再充(chong)電(dian)(dian)。

　　涓流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)：充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)開始前(qian)，AP5056先檢查(cha)輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源，當輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源大于最小(xiao)工作(zuo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)或(huo)欠壓(ya)(ya)鎖定閾值，并且芯(xin)(xin)片使(shi)能端接高電(dian)(dian)(dian)(dian)(dian)(dian)(dian)平時，AP5056開始對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。AP5056先檢查(cha)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的狀態(tai)。如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)高于3V，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)則(ze)(ze)進入(ru)恒(heng)(heng)流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)；而(er)如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低于3V時，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)則(ze)(ze)進入(ru)涓流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)模式。涓流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)是恒(heng)(heng)流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)的十分之(zhi)一(還是以(yi)恒(heng)(heng)定充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)為(wei)1A舉例，則(ze)(ze)涓流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(liu)(liu)為(wei)100mA)，涓流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態(tai)一直保持延續(xu)到(dao)AP5056芯(xin)(xin)片探測到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)達到(dao)3V后結束(shu)，之(zhi)后進入(ru)恒(heng)(heng)流(liu)(liu)(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)階段(duan)。

　　圖2：AP5056封裝。

　　恒(heng)流(liu)充電(dian)(dian)：恒(heng)流(liu)充電(dian)(dian)模(mo)式中，充電(dian)(dian)電(dian)(dian)流(liu)由PROG腳與GND間(jian)的(de)電(dian)(dian)阻RPROG確定。(參見下文“可編程的(de)充電(dian)(dian)電(dian)(dian)流(liu)”)

　　IBAT = (VPROG/ RPROG)?1000 (VPROG的典(dian)型值為1V)

　　AP5056進入(ru)恒(heng)流(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)模(mo)式(shi)中(zhong)后，將(jiang)一直按設(she)定的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)值保(bao)持充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，直到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池慢(man)(man)慢(man)(man)到達(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)調(diao)節點4.2V，轉而進入(ru)恒(heng)壓(ya)(ya)(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。恒(heng)壓(ya)(ya)(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)：在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)慢(man)(man)慢(man)(man)接近4.2V時，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器就(jiu)漸漸轉為恒(heng)壓(ya)(ya)(ya)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。此(ci)時原(yuan)先的(de)恒(heng)流(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)也慢(man)(man)慢(man)(man)減小，并(bing)隨著(zhu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池容量越來越接近最大(da)容量而急劇下降。 充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)完成與(yu)再(zai)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)：當充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)被探測(ce)到減小至恒(heng)流(liu)充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)10%后，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器終止向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，進入(ru)低功耗的(de)待機模(mo)式(shi)。 在待機模(mo)式(shi)下，AP5056會繼(ji)續(xu)檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池端的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)，如果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)降到4.05V以下，則充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器將(jiang)再(zai)次向(xiang)(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

　　可編程的(de)充(chong)電(dian)電(dian)流：AP5056的(de)充(chong)電(dian)電(dian)流由連接在PROG腳與(yu)GND之間RPROG電(dian)阻來確定(ding)，計(ji)算公(gong)式如下：

　　IBAT = (VPROG/ RPROG)?1000 (VPROG的典型值為(wei)1V)

　　例如(ru)，客戶需要得到一(yi)個1A的充電電流(liu)的話(hua)，根據公式得到

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

　　圖(tu)3顯(xian)示了(le)RPROG為(wei)1K和(he)2K時，不同的電(dian)源輸入Vcc 與(yu)充電(dian)電(dian)流Ibat之間的關系(xi)圖(tu)，可以看到充電(dian)輸出電(dian)流基本(ben)沒有很大變(bian)化(hua)，只與(yu)RPROG的設定值有關系(xi)。

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

　　典型應用電路

　　圖(tu)4給(gei)出(chu)的是典(dian)型(xing)的應用電(dian)(dian)路，電(dian)(dian)路中R1, R2由NTC熱敏電(dian)(dian)阻(zu)值來確定。設熱敏電(dian)(dian)阻(zu)在(zai)最低工作(zuo)溫(wen)度(du)時(shi)(shi)的電(dian)(dian)阻(zu)為RTL，在(zai)最高工作(zuo)溫(wen)度(du)時(shi)(shi)的電(dian)(dian)阻(zu)為RTH(RTL與RTH的數(shu)據(ju)可查電(dian)(dian)池廠(chang)方數(shu)據(ju)或做實驗(yan)得到(dao))，則R1，R2的阻(zu)值分別為：

　　圖4：AP5056應用電(dian)路。

　　如果用戶只(zhi)關心高溫保護，而(er)不用關心低溫保護，則可將(jiang)R2去(qu)掉，只(zhi)保留R1，這(zhe)時R1的計算公(gong)式變為(wei)：

　　直流適配器與USB組合的方案(an)

　當(dang)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)需(xu)要直流(liu)適(shi)配器(qi)(qi)與USB充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)兩者(zhe)都能用(yong)(yong)時，可(ke)采(cai)(cai)用(yong)(yong)圖5所示的方案。方案中，假(jia)如使用(yong)(yong)USB口進行供電(dian)(dian)(dian)(dian)(dian)(dian)的話，MOS-P門極(ji)(ji)接(jie)地，USB電(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)通(tong)過MOS-P導通(tong)至(zhi)VCC，同(tong)時MOS-N處于關斷狀(zhuang)態(tai)，PROG上的編程電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)為2K，即(ji)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)設定為500mA，這樣可(ke)防止USB接(jie)口被(bei)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)(qi)拉死(si)；而(er)當(dang)采(cai)(cai)用(yong)(yong)5V直流(liu)適(shi)配器(qi)(qi)的時候，適(shi)配器(qi)(qi)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)通(tong)過肖特基二極(ji)(ji)管(guan)加至(zhi)VCC腳(jiao)，MOS-P由于門極(ji)(ji)為高電(dian)(dian)(dian)(dian)(dian)(dian)平而(er)被(bei)截(jie)止，不(bu)會(hui)對USB口產生影響。同(tong)時MOS-N由于門極(ji)(ji)為高電(dian)(dian)(dian)(dian)(dian)(dian)平而(er)導通(tong)，此時PROG腳(jiao)上的編程電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)相(xiang)當(dang)于1K(2個2K電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)并聯)，即(ji)設定充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)為1A，來對鋰(li)離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)池進行快速充(chong)(chong)電(dian)(dian)(dian)(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結的導(dao)通電(dian)(dian)壓(ya)隨溫(wen)(wen)度(du)升(sheng)(sheng)(sheng)高而(er)降低，而(er)其變化值(zhi)隨溫(wen)(wen)度(du)的升(sheng)(sheng)(sheng)高而(er)增加(jia)的特性，AP5056設計了集成于芯片(pian)內部(bu)的過熱(re)保(bao)護功(gong)能(neng)。當(dang)(dang)內部(bu)溫(wen)(wen)度(du)傳感(gan)器升(sheng)(sheng)(sheng)至(zhi)約125℃以(yi)上時，內部(bu)的熱(re)保(bao)護電(dian)(dian)路將(jiang)自動減小充(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)的電(dian)(dian)流(liu)(liu)值(zhi)，隨著溫(wen)(wen)度(du)的不斷升(sheng)(sheng)(sheng)高，當(dang)(dang)溫(wen)(wen)度(du)達到145℃的時候(hou)，則可完全關閉(bi)充(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)。該功(gong)能(neng)可以(yi)讓(rang)用戶放(fang)心使用最大功(gong)率的充(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)而(er)無需擔心芯片(pian)被(bei)損壞(huai)。

　　充電狀態指示

　　AP5056有CHRG和STDBY兩個狀態(tai)輸出指(zhi)示(shi)。當充(chong)電(dian)器處于充(chong)電(dian)狀態(tai)時，CHRG置低(di)電(dian)平，STDBY輸出高阻(zu)態(tai)；當電(dian)池處于充(chong)滿狀態(tai)時，CHRG變為高阻(zu)態(tai)，STDBY被拉為低(di)電(dian)平。

　　如果不(bu)需要用(yong)到狀(zhuang)態指(zhi)示(shi)功能，可(ke)以將(jiang)不(bu)用(yong)的相應的狀(zhuang)態輸出指(zhi)示(shi)腳接地(di)。

　　指示燈狀態

　　布板的注意事項

　　AP5056采用SOP8-PP封裝(zhuang)，芯(xin)片(pian)(pian)底(di)部帶有(you)(you)散(san)(san)熱(re)(re)片(pian)(pian)，以便于(yu)將(jiang)(jiang)芯(xin)片(pian)(pian)工作時產生的(de)熱(re)(re)量通過散(san)(san)熱(re)(re)片(pian)(pian)發散(san)(san)出去，因此(ci)，為了(le)達(da)到(dao)較好的(de)散(san)(san)熱(re)(re)效果，散(san)(san)熱(re)(re)片(pian)(pian)下(xia)的(de)PC板銅(tong)(tong)箔(bo)(bo)(bo)(bo)面積要盡(jin)可能(neng)(neng)的(de)寬闊，并將(jiang)(jiang)之延伸至外(wai)面更(geng)(geng)大(da)，更(geng)(geng)寬的(de)銅(tong)(tong)箔(bo)(bo)(bo)(bo)面積，而且需將(jiang)(jiang)散(san)(san)熱(re)(re)片(pian)(pian)與(yu)散(san)(san), 熱(re)(re)片(pian)(pian)下(xia)的(de)銅(tong)(tong)箔(bo)(bo)(bo)(bo)用焊(han)錫焊(han)接(jie)(jie)在一(yi)起，以增加(jia)熱(re)(re)的(de)傳導性；此(ci)外(wai)，利用多個通孔將(jiang)(jiang)上層銅(tong)(tong)箔(bo)(bo)(bo)(bo)與(yu)下(xia)層銅(tong)(tong)箔(bo)(bo)(bo)(bo)連接(jie)(jie)起來能(neng)(neng)夠(gou)更(geng)(geng)有(you)(you)效地拓展散(san)(san)熱(re)(re)面積，有(you)(you)利于(yu)將(jiang)(jiang)熱(re)(re)量散(san)(san)至周圍環境(jing)中(zhong)，增加(jia)充電芯(xin)片(pian)(pian)的(de)散(san)(san)熱(re)(re)效果(如圖6所(suo)示)。

　　圖(tu)6：AP5056布板示意圖(tu)。

　　在(zai)芯片散(san)熱良好的情況下，AP5056可(ke)提供(gong)電(dian)路最大(da)充電(dian)電(dian)流(liu)為(wei)(wei)1600MA，實驗中，在(zai)室溫狀態下，充電(dian)電(dian)流(liu)設(she)置為(wei)(wei)1600MA，連續工作15分鐘(zhong)(zhong)，IC表面(mian)溫度為(wei)(wei)60℃；設(she)置為(wei)(wei)1000MA時，連續工作15分鐘(zhong)(zhong)，IC表面(mian)溫度為(wei)(wei)50℃。

％時：
充(chong)電時(shi)間（小時(shi)）＝電池容(rong)量（mAH）×1.1÷充(chong)電電流(mA)