電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)大(da)于電(dian)(dian)(dian)池(chi)容量的(de)20 隨著當今數碼電(dian)(dian)(dian)子(zi)(zi)(zi)產品功能(neng)的(de)不(bu)斷增(zeng)加，LCD屏(ping)(ping)幕越(yue)(yue)來越(yue)(yue)大(da)，以及不(bu)斷增(zeng)強的(de)多媒體視屏(ping)(ping)功能(neng)，市面上(shang)鋰離子(zi)(zi)(zi)/聚合物電(dian)(dian)(dian)池(chi)的(de)容量也(ye)做(zuo)得(de)越(yue)(yue)來越(yue)(yue)大(da)。與此同時(shi)，消費者(zhe)對縮短(duan)大(da)容量電(dian)(dian)(dian)池(chi)的(de)充電(dian)(dian)(dian)時(shi)間提出了(le)期望。為了(le)能(neng)更快速有效地對這些大(da)容量電(dian)(dian)(dian)池(chi)進行充電(dian)(dian)(dian)，以滿足消費者(zhe)不(bu)斷增(zeng)長(chang)的(de)需求，無錫芯(xin)朋微電(dian)(dian)(dian)子(zi)(zi)(zi)推(tui)出了(le)大(da)電(dian)(dian)(dian)流(liu)鋰離子(zi)(zi)(zi)電(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)芯(xin)片AP5056。

　　AP5056是可以對單節鋰離子或(huo)鋰聚(ju)合物可充電電池進行恒流/恒壓(ya)充電的充電器(qi)電路(lu)。器(qi)件內部(bu)采用(yong)PMOSFET架構(gou)，應用(yong)時不(bu)需要外部(bu)另加阻流二極管。熱反饋電路(lu)可以自動(dong)調節充電電流，使器(qi)件在(zai)功耗(hao)比(bi)較(jiao)大或(huo)者環境溫(wen)度比(bi)較(jiao)高的情況下將芯(xin)片溫(wen)度控制在(zai)安全范圍內。

　　AP5056只需要極少的(de)外圍元器(qi)件，可以(yi)適應USB 電(dian)(dian)源和適配(pei)器(qi)電(dian)(dian)源工作，非常適用于便(bian)攜式應用的(de)領域。充(chong)電(dian)(dian)輸出電(dian)(dian)壓(ya)為(wei)4.2V，充(chong)電(dian)(dian)電(dian)(dian)流(liu)的(de)大小可以(yi)通過一(yi)個外部電(dian)(dian)阻設置(zhi)。在(zai)恒壓(ya)充(chong)電(dian)(dian)階(jie)段中，當充(chong)電(dian)(dian)電(dian)(dian)流(liu)降至設定值1/10 時，AP5056將終(zhong)止(zhi)充(chong)電(dian)(dian)循(xun)環。

　　當輸(shu)入(ru)(ru)電(dian)(dian)(dian)壓(ya)(交流適配器(qi)或者USB電(dian)(dian)(dian)源(yuan))掉電(dian)(dian)(dian)時(shi)(shi)，AP5056自動(dong)進入(ru)(ru)低功耗的睡眠模式(shi)，此時(shi)(shi)電(dian)(dian)(dian)池(chi)的電(dian)(dian)(dian)流消耗小(xiao)于2微安。其它功能(neng)包括輸(shu)入(ru)(ru)電(dian)(dian)(dian)壓(ya)過低鎖存(cun)、芯片使(shi)能(neng)輸(shu)入(ru)(ru)、自動(dong)再(zai)充電(dian)(dian)(dian)、電(dian)(dian)(dian)池(chi)溫(wen)度監控以及狀態指示等功能(neng)。

　　充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)：AP5056在整個(ge)電(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)過(guo)程(cheng)中(zhong)有四種基(ji)本充(chong)電(dian)(dian)(dian)(dian)模式：涓流充(chong)電(dian)(dian)(dian)(dian)、恒流充(chong)電(dian)(dian)(dian)(dian)、恒壓(ya)充(chong)電(dian)(dian)(dian)(dian)和充(chong)電(dian)(dian)(dian)(dian)完成與再充(chong)電(dian)(dian)(dian)(dian)。

　　涓(juan)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)：充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)開始前，AP5056先檢查(cha)(cha)輸入(ru)電(dian)(dian)(dian)(dian)源，當輸入(ru)電(dian)(dian)(dian)(dian)源大于最小工(gong)作(zuo)電(dian)(dian)(dian)(dian)壓(ya)或(huo)欠壓(ya)鎖(suo)定閾值，并(bing)且芯片(pian)使(shi)能端接(jie)高(gao)電(dian)(dian)(dian)(dian)平(ping)時(shi)(shi)，AP5056開始對電(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)。AP5056先檢查(cha)(cha)電(dian)(dian)(dian)(dian)池的狀態(tai)。如果(guo)(guo)電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)高(gao)于3V，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器則進入(ru)恒(heng)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)；而(er)如果(guo)(guo)電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)低于3V時(shi)(shi)，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)器則進入(ru)涓(juan)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)模式(shi)。涓(juan)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)是恒(heng)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)的十分之一(還是以恒(heng)定充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)為1A舉例，則涓(juan)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)為100mA)，涓(juan)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)狀態(tai)一直保持延續到AP5056芯片(pian)探測到電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)達到3V后(hou)結(jie)束，之后(hou)進入(ru)恒(heng)流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)階段(duan)。

　　圖2：AP5056封裝(zhuang)。

　　恒流(liu)充(chong)電：恒流(liu)充(chong)電模式(shi)中，充(chong)電電流(liu)由PROG腳與(yu)GND間的(de)電阻RPROG確定(ding)。(參見(jian)下文“可編程的(de)充(chong)電電流(liu)”)

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

　　AP5056進入(ru)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)模(mo)式中(zhong)后，將一直(zhi)按設(she)定的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)值保持(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，直(zhi)到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)慢(man)(man)(man)(man)慢(man)(man)(man)(man)到達(da)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓調(diao)節點4.2V，轉而進入(ru)恒(heng)(heng)壓充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。恒(heng)(heng)壓充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)：在(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓慢(man)(man)(man)(man)慢(man)(man)(man)(man)接近4.2V時，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)就漸(jian)漸(jian)轉為恒(heng)(heng)壓充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。此時原(yuan)先的(de)(de)恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)也慢(man)(man)(man)(man)慢(man)(man)(man)(man)減小，并隨著電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)容量(liang)越來(lai)越接近最大(da)容量(liang)而急劇下(xia)降(jiang)。 充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)完成與再充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)：當(dang)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)被(bei)探(tan)測到減小至恒(heng)(heng)流(liu)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)10%后，充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)終止向(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，進入(ru)低(di)功耗的(de)(de)待機模(mo)式。 在(zai)待機模(mo)式下(xia)，AP5056會繼續檢(jian)測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)端的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，如果(guo)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓降(jiang)到4.05V以(yi)下(xia)，則充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)將再次向(xiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

　　可編程(cheng)的充電電流：AP5056的充電電流由連接在PROG腳(jiao)與GND之間RPROG電阻來(lai)確定，計(ji)算公式如下：

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

　　例如，客戶需(xu)要得到(dao)一個1A的充電電流的話，根據公式(shi)得到(dao)

　　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，不同的電(dian)源輸入Vcc 與充電(dian)電(dian)流(liu)Ibat之間(jian)的關系圖，可以看到充電(dian)輸出電(dian)流(liu)基本沒有(you)很(hen)大變(bian)化(hua)，只與RPROG的設定值有(you)關系。

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

　　典型應用電路

　　圖(tu)4給出的(de)是典型的(de)應用電(dian)路，電(dian)路中R1, R2由(you)NTC熱敏電(dian)阻(zu)(zu)值(zhi)(zhi)來確定。設熱敏電(dian)阻(zu)(zu)在最低工(gong)作溫度時的(de)電(dian)阻(zu)(zu)為RTL，在最高工(gong)作溫度時的(de)電(dian)阻(zu)(zu)為RTH(RTL與RTH的(de)數據可(ke)查電(dian)池廠方數據或做實驗(yan)得到)，則R1，R2的(de)阻(zu)(zu)值(zhi)(zhi)分別為：

　　圖4：AP5056應用(yong)電路。

　　如果用(yong)戶只關(guan)(guan)心(xin)高溫(wen)(wen)保護，而不用(yong)關(guan)(guan)心(xin)低溫(wen)(wen)保護，則可將R2去掉(diao)，只保留(liu)R1，這(zhe)時R1的計(ji)算公(gong)式變為：

　　直流適(shi)配器與USB組(zu)合的方(fang)案

　當(dang)充(chong)(chong)電(dian)(dian)器需要直(zhi)流(liu)(liu)適(shi)配(pei)器與USB充(chong)(chong)電(dian)(dian)兩者都(dou)能用(yong)時，可采(cai)用(yong)圖(tu)5所示的(de)方(fang)案。方(fang)案中(zhong)，假如使(shi)用(yong)USB口進行供(gong)電(dian)(dian)的(de)話，MOS-P門極(ji)接(jie)地，USB電(dian)(dian)源通過MOS-P導通至(zhi)(zhi)VCC，同時MOS-N處于(yu)關斷(duan)狀態，PROG上的(de)編程電(dian)(dian)阻(zu)(zu)(zu)為(wei)2K，即充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)設定為(wei)500mA，這樣可防止(zhi)USB接(jie)口被充(chong)(chong)電(dian)(dian)器拉(la)死(si)；而(er)當(dang)采(cai)用(yong)5V直(zhi)流(liu)(liu)適(shi)配(pei)器的(de)時候，適(shi)配(pei)器電(dian)(dian)流(liu)(liu)通過肖特基二極(ji)管加至(zhi)(zhi)VCC腳，MOS-P由(you)于(yu)門極(ji)為(wei)高電(dian)(dian)平而(er)被截止(zhi)，不會對(dui)USB口產(chan)生影(ying)響。同時MOS-N由(you)于(yu)門極(ji)為(wei)高電(dian)(dian)平而(er)導通，此時PROG腳上的(de)編程電(dian)(dian)阻(zu)(zu)(zu)相當(dang)于(yu)1K(2個(ge)2K電(dian)(dian)阻(zu)(zu)(zu)并聯)，即設定充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)為(wei)1A，來(lai)對(dui)鋰離子電(dian)(dian)池進行快速充(chong)(chong)電(dian)(dian)。

　　圖(tu)5：交流適配器與USB組合的方案。

　　芯片熱保護功能

　　利用晶(jing)體管PN結的(de)(de)(de)(de)導通電壓隨(sui)溫(wen)度(du)升(sheng)(sheng)高而(er)降低，而(er)其變(bian)化(hua)值隨(sui)溫(wen)度(du)的(de)(de)(de)(de)升(sheng)(sheng)高而(er)增加的(de)(de)(de)(de)特性，AP5056設計(ji)了集成于芯片內(nei)部(bu)(bu)的(de)(de)(de)(de)過熱(re)(re)保護功能。當(dang)內(nei)部(bu)(bu)溫(wen)度(du)傳感器升(sheng)(sheng)至約125℃以上時，內(nei)部(bu)(bu)的(de)(de)(de)(de)熱(re)(re)保護電路將自動減小充電電流的(de)(de)(de)(de)電流值，隨(sui)著(zhu)溫(wen)度(du)的(de)(de)(de)(de)不斷升(sheng)(sheng)高，當(dang)溫(wen)度(du)達到145℃的(de)(de)(de)(de)時候，則可完全關(guan)閉充電電流。該功能可以讓用戶放心使(shi)用最大功率的(de)(de)(de)(de)充電電流而(er)無需擔心芯片被損壞。

　　充電狀態指示

　　AP5056有CHRG和STDBY兩個狀(zhuang)態(tai)輸出指示(shi)。當充(chong)電(dian)器(qi)處(chu)于充(chong)電(dian)狀(zhuang)態(tai)時，CHRG置(zhi)低(di)電(dian)平(ping)，STDBY輸出高阻態(tai)；當電(dian)池(chi)處(chu)于充(chong)滿狀(zhuang)態(tai)時，CHRG變為(wei)高阻態(tai)，STDBY被拉(la)為(wei)低(di)電(dian)平(ping)。

　　如果不需要用到狀(zhuang)(zhuang)態指示功(gong)能，可以將不用的相應(ying)的狀(zhuang)(zhuang)態輸出指示腳接地。

　　指示燈狀態

　　布板的注意事項

　　AP5056采用SOP8-PP封(feng)裝，芯(xin)片(pian)底部(bu)帶有散(san)(san)(san)熱(re)(re)片(pian)，以便于將(jiang)(jiang)(jiang)芯(xin)片(pian)工作時產(chan)生的(de)(de)熱(re)(re)量通過散(san)(san)(san)熱(re)(re)片(pian)發散(san)(san)(san)出去，因此，為了(le)達(da)到較好的(de)(de)散(san)(san)(san)熱(re)(re)效(xiao)果，散(san)(san)(san)熱(re)(re)片(pian)下(xia)的(de)(de)PC板(ban)銅(tong)箔(bo)(bo)面(mian)(mian)積要盡(jin)可(ke)能的(de)(de)寬(kuan)闊，并(bing)將(jiang)(jiang)(jiang)之延伸至外面(mian)(mian)更(geng)大(da)，更(geng)寬(kuan)的(de)(de)銅(tong)箔(bo)(bo)面(mian)(mian)積，而且需將(jiang)(jiang)(jiang)散(san)(san)(san)熱(re)(re)片(pian)與(yu)散(san)(san)(san), 熱(re)(re)片(pian)下(xia)的(de)(de)銅(tong)箔(bo)(bo)用焊錫焊接(jie)在一起，以增加熱(re)(re)的(de)(de)傳導性；此外，利用多個通孔將(jiang)(jiang)(jiang)上層(ceng)銅(tong)箔(bo)(bo)與(yu)下(xia)層(ceng)銅(tong)箔(bo)(bo)連接(jie)起來能夠(gou)更(geng)有效(xiao)地拓展(zhan)散(san)(san)(san)熱(re)(re)面(mian)(mian)積，有利于將(jiang)(jiang)(jiang)熱(re)(re)量散(san)(san)(san)至周圍環(huan)境中，增加充電芯(xin)片(pian)的(de)(de)散(san)(san)(san)熱(re)(re)效(xiao)果(如圖6所示(shi))。

　　圖(tu)6：AP5056布板示(shi)意圖(tu)。

　　在(zai)芯片散(san)熱良(liang)好(hao)的情況(kuang)下(xia)，AP5056可提供電(dian)(dian)路最大充(chong)電(dian)(dian)電(dian)(dian)流為(wei)1600MA，實驗中(zhong)，在(zai)室(shi)溫狀態下(xia)，充(chong)電(dian)(dian)電(dian)(dian)流設(she)(she)置(zhi)為(wei)1600MA，連續(xu)工作15分鐘，IC表面(mian)溫度為(wei)60℃；設(she)(she)置(zhi)為(wei)1000MA時，連續(xu)工作15分鐘，IC表面(mian)溫度為(wei)50℃。

％時：
充電(dian)(dian)時間（小時）＝電(dian)(dian)池容量（mAH）×1.1÷充電(dian)(dian)電(dian)(dian)流(mA)