一次性電池不能夠充電，完全放電后的電池即為報廢電池。二次電池可以多次充電，但不同的化學特性對充電的要求也不同，特別是“快充”控制。目前，最常用的可充電電池是Li+、鎳氫(NiMH)、鎳鎘(Nicd)和鉛酸電池，其它類型的電池還很多，但沒有大規模投入使用。因為本文僅討論利用交流適配器供電的充電器設計，沒有考慮汽車電源供電的SLI鉛酸電池或更大容量電池的充電器。     

    不(bu)同化(hua)學類型的電(dian)池對充電(dian)器(qi)的要求   

    通常快(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)比涓流(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)更受歡迎，但(dan)快(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)對電(dian)(dian)(dian)(dian)(dian)路(lu)的(de)(de)(de)(de)要(yao)求也復雜，鎳氫或鎳鎘(ge)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)快(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)技術(shu)與其它電(dian)(dian)(dian)(dian)(dian)池(chi)也是(shi)(shi)不同的(de)(de)(de)(de)。鎳鎘(ge)和(he)鎳氫電(dian)(dian)(dian)(dian)(dian)池(chi)通常在(zai)恒流(liu)狀態下快(kuai)充(chong)(chong)(chong)，而不是(shi)(shi)恒壓(ya)狀態下。快(kuai)充(chong)(chong)(chong)終(zhong)止檢測基于電(dian)(dian)(dian)(dian)(dian)壓(ya)和(he)溫度的(de)(de)(de)(de)變(bian)化率，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器還應具備過(guo)壓(ya)保(bao)護和(he)過(guo)熱保(bao)護功能。Li+和(he)鉛酸電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器必須(xu)保(bao)證作用到電(dian)(dian)(dian)(dian)(dian)池(chi)上的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)和(he)電(dian)(dian)(dian)(dian)(dian)流(liu)最大值在(zai)規定(ding)的(de)(de)(de)(de)范(fan)圍(wei)內，當(dang)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)維(wei)持在(zai)最大單節(jie)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)下降到一個較低值時，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器終(zhong)止充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。Li+和(he)鉛酸電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器的(de)(de)(de)(de)區別在(zai)于所允許的(de)(de)(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)、最大電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)，另外(wai)鉛酸電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器一般具有浮(fu)充(chong)(chong)(chong)能力(浮(fu)充(chong)(chong)(chong)是(shi)(shi)為了(le)補充(chong)(chong)(chong)鉛酸電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)自放電(dian)(dian)(dian)(dian)(dian)，而對一個已經完全充(chong)(chong)(chong)滿的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池(chi)繼續輸入充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)(de)(de)技術(shu))，Li+電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)(de)自放電(dian)(dian)(dian)(dian)(dian)非常低，所以不需要(yao)浮(fu)充(chong)(chong)(chong)。    

    Li+電(dian)池    

    為便攜式產品選擇(ze)(ze)電(dian)(dian)(dian)池時(shi)，最重(zhong)要的(de)是(shi)高能(neng)量(liang)密(mi)度、尺(chi)寸(cun)、重(zhong)量(liang)和價格。迄今(jin)為止，Li+電(dian)(dian)(dian)池在最為流(liu)行的(de)電(dian)(dian)(dian)池中能(neng)夠提供最高的(de)體積和能(neng)量(liang)密(mi)度，但(dan)其(qi)每瓦時(shi)的(de)成(cheng)本(ben)也(ye)較(jiao)高。鉛酸(suan)電(dian)(dian)(dian)池的(de)每瓦時(shi)成(cheng)本(ben)最低，但(dan)比較(jiao)笨重(zhong)。本(ben)文以Li+電(dian)(dian)(dian)池為例討論充電(dian)(dian)(dian)器的(de)設計，它在便攜式產品中已經被(bei)普遍(bian)使用。我(wo)們選擇(ze)(ze)780mA的(de)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)和4.2V的(de)終止電(dian)(dian)(dian)壓。 

 通用輸入交流(liu)電(dian)壓的(de)離線式Li+電(dian)池充電(dian)器。    

    所示充電(dian)(dian)(dian)器(qi)(qi)(qi)無(wu)需微(wei)處理器(qi)(qi)(qi)干預，輸入電(dian)(dian)(dian)源可以(yi)采用全球范圍的(de)(de)任何(he)交流(liu)電(dian)(dian)(dian)源，省去了大(da)體積60Hz變壓器(qi)(qi)(qi)，而且可提(ti)供單節Li+電(dian)(dian)(dian)池(chi)所要求的(de)(de)精確的(de)(de)充電(dian)(dian)(dian)電(dian)(dian)(dian)壓和電(dian)(dian)(dian)流(liu)。充電(dian)(dian)(dian)器(qi)(qi)(qi)IC(U4)集成了全面的(de)(de)保(bao)護功能(電(dian)(dian)(dian)壓、電(dian)(dian)(dian)流(liu)和自(zi)保(bao)護)，確保(bao)Li+電(dian)(dian)(dian)池(chi)的(de)(de)安(an)全充電(dian)(dian)(dian)。    

    假(jia)設Li+電(dian)池帶有過(guo)流(liu)、過(guo)壓和過(guo)熱(re)保護，這些(xie)保護特性在(zai)電(dian)池包里是必需的，因為充電(dian)期(qi)間一旦(dan)電(dian)路出現(xian)故障，Li+電(dian)池將存在(zai)很大的危險性，過(guo)流(liu)、過(guo)壓或溫度過(guo)高(gao)都有可(ke)能造成Li+電(dian)池爆(bao)炸。    

    電路描述(shu)     

    包括兩顆(ke)主器件(U1和U4)、精密基準(U3)和光耦(U2)。U1是離(li)線(xian)式開(kai)關控(kong)制器，配合隔離(li)變(bian)壓器、光耦和基準產(chan)生隔離(li)的穩壓直(zhi)流(liu)輸(shu)出。直(zhi)流(liu)電(dian)(dian)(dian)壓供給電(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)器(U4)，U4提供電(dian)(dian)(dian)流(liu)限(xian)制、電(dian)(dian)(dian)壓調節、電(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)和充電(dian)(dian)(dian)指示等功能。本方案中(zhong)，U4是一款簡單的線(xian)性充電(dian)(dian)(dian)器，內置調整管，結合其熱(re)控(kong)制環(huan)路提供快速充電(dian)(dian)(dian)。    

    MAX5022的特性     

    U1(MAX5022)在(zai)寬輸入(ru)(ru)范圍(wei)(wei)的(de)(de)應用(yong)中(zhong)很容易設(she)計，本文所(suo)提(ti)供的(de)(de)方案(an)要求能(neng)夠(gou)滿足(zu)(zu)全球各(ge)地的(de)(de)交(jiao)流(liu)電源(yuan)規格，這里假設(she)通(tong)用(yong)的(de)(de)輸入(ru)(ru)電源(yuan)電壓范圍(wei)(wei)為85VAC至265VAC。MAX5022的(de)(de)輸入(ru)(ru)范圍(wei)(wei)指標以(yi)及評估板(ban)(ban)電路的(de)(de)輸入(ru)(ru)范圍(wei)(wei)恰好滿足(zu)(zu)這一需求。對于所(suo)示充電器(qi)的(de)(de)電源(yuan)端(duan)MAX5022評估板(ban)(ban)不需要作任何修改，隔(ge)離端(duan)只需對評估板(ban)(ban)的(de)(de)電阻值稍作修改。    

    對(dui)于(yu)更(geng)大功率(lv)的(de)應用(yong)，只需選(xuan)取(qu)功率(lv)較(jiao)大的(de)開(kai)關管和能夠處(chu)理更(geng)大功率(lv)的(de)變壓(ya)器(qi)(qi)即可。圖1所(suo)示電(dian)路要(yao)求(qiu)充電(dian)電(dian)流為(wei)780mA，最(zui)大電(dian)池電(dian)壓(ya)為(wei)4.2V。對(dui)充電(dian)電(dian)源的(de)要(yao)求(qiu)與MAX5022評估板(ban)(ban)所(suo)提供的(de)輸出相吻合：5V@1A，因此，不需要(yao)更(geng)換評估板(ban)(ban)的(de)晶體管和變壓(ya)器(qi)(qi)。U4采用(yong)SOT23封裝，所(suo)以，充電(dian)器(qi)(qi)的(de)尺(chi)(chi)寸(cun)在(zai)很(hen)大程度上取(qu)決于(yu)應用(yong)對(dui)充電(dian)電(dian)源的(de)需求(qiu)。變壓(ya)器(qi)(qi)是電(dian)路中尺(chi)(chi)寸(cun)最(zui)大的(de)元件(jian)，由于(yu)開(kai)關控制器(qi)(qi)的(de)工作頻率(lv)大于(yu)250kHz，允(yun)許(xu)系統選(xuan)用(yong)小(xiao)尺(chi)(chi)寸(cun)的(de)變壓(ya)器(qi)(qi)。     

    上電(dian)(dian)時(shi)(shi)，在開(kai)關控制(zhi)器工作之前，U1調節器直接(jie)通(tong)過泄漏(lou)電(dian)(dian)阻R1、R2從(cong)整流(liu)(liu)通(tong)路吸(xi)(xi)取少量的(de)電(dian)(dian)流(liu)(liu)，兩個電(dian)(dian)阻阻值保證(zheng)每(mei)個電(dian)(dian)阻上的(de)壓降不(bu)(bu)會超(chao)出(chu)每(mei)個電(dian)(dian)阻的(de)容限，Vin引(yin)腳電(dian)(dian)壓不(bu)(bu)會超(chao)出(chu)其(qi)28V額(e)定值(30V為絕對(dui)最大(da)值)，U1在輸入電(dian)(dian)壓達到24V時(shi)(shi)開(kai)始開(kai)關操作，并(bing)吸(xi)(xi)取更大(da)的(de)電(dian)(dian)流(liu)(liu)(高于R1、R2所能提供的(de)電(dian)(dian)流(liu)(liu))，在變壓器副邊線圈能夠提供足夠的(de)能量之前，額(e)外的(de)電(dian)(dian)流(liu)(liu)由Vin引(yin)腳的(de)旁路電(dian)(dian)容供給。這(zhe)種處理方式能夠適(shi)合較寬的(de)輸入電(dian)(dian)壓范圍(wei)，對(dui)效率的(de)影響也(ye)很小(xiao)，這(zhe)是因(yin)為在啟動過程中只(zhi)需極小(xiao)的(de)供電(dian)(dian)電(dian)(dian)流(liu)(liu)(典型(xing)值為50uA)。   

    為了(le)防止U1的(de)Vin引腳出現過壓，可(ke)以在Vin與地之間接一(yi)個26V至30V的(de)齊納(na)管，電(dian)壓值(zhi)需(xu)要高于(yu)(yu)(yu)欠(qian)壓鎖存電(dian)壓的(de)最(zui)大(da)值(zhi)，低于(yu)(yu)(yu)該引腳所(suo)允(yun)許(xu)的(de)最(zui)大(da)絕對電(dian)壓。如(ru)果器件沒有啟動(dong)正常的(de)開關操作(zuo)，則可(ke)認為電(dian)路發生了(le)某些問題，所(suo)以，這一(yi)保(bao)護措施對于(yu)(yu)(yu)U1來說并不(bu)是必需(xu)的(de)。     

    U1是一款電(dian)(dian)流(liu)(liu)(liu)(liu)模式(shi)PWM控(kong)制(zhi)器，具(ju)有(you)逐(zhu)周期限(xian)流(liu)(liu)(liu)(liu)電(dian)(dian)路(lu)，必要時其占空(kong)比(bi)可(ke)以提高到(dao)75%，非常適合圖(tu)1所示的(de)反(fan)激拓撲。原邊開關電(dian)(dian)流(liu)(liu)(liu)(liu)檢(jian)測采用尺寸為1206的(de)1.78Ω電(dian)(dian)阻(zu)(R7)，該(gai)電(dian)(dian)阻(zu)限(xian)制(zhi)了變壓器原邊的(de)最大(da)電(dian)(dian)流(liu)(liu)(liu)(liu)。固定開關頻率(lv)和(he)最大(da)占空(kong)比(bi)限(xian)制(zhi)使得最大(da)限(xian)流(liu)(liu)(liu)(liu)具(ju)有(you)輸(shu)出短路(lu)保(bao)護(hu)功能。   

    一(yi)旦(dan)短路輸(shu)出造成(cheng)電(dian)路達(da)到(dao)了上述限(xian)制(zhi)條(tiao)件，第三組線圈將無法提供10V以上的電(dian)壓(UVLO的低電(dian)壓門限(xian))，U1將再次進入啟動狀態，停止開(kai)關操作(zuo)。短路故障解除后(hou)系統會(hui)自動恢復正常的工作(zuo)狀態。   

    電壓(ya)調(diao)節   

    變壓(ya)(ya)器副邊(bian)的(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)經(jing)過整流、濾波，然后由(you)R4、R5分壓(ya)(ya)在并聯型(xing)穩(wen)壓(ya)(ya)器U3的(de)(de)調節點(dian)產生(sheng)1.24V(對應于(yu)4.5V輸出)的(de)(de)反饋電(dian)(dian)(dian)(dian)壓(ya)(ya)。為保證電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)器正常工作，4.5V是最低電(dian)(dian)(dian)(dian)壓(ya)(ya)(包(bao)括容差)。因為充(chong)電(dian)(dian)(dian)(dian)器采用的(de)(de)是線(xian)性結構，充(chong)電(dian)(dian)(dian)(dian)效(xiao)率(lv)與輸入、輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)差值成反比(bi)，用最低電(dian)(dian)(dian)(dian)壓(ya)(ya)為充(chong)電(dian)(dian)(dian)(dian)器供電(dian)(dian)(dian)(dian)有助于(yu)降低功率(lv)損耗。   

    當調(diao)節(jie)點電(dian)(dian)(dian)壓(ya)高于(yu)1.24V時(shi)(shi)，并聯(lian)型穩(wen)壓(ya)器(qi)將吸入(ru)電(dian)(dian)(dian)流(liu)，導(dao)通光(guang)耦(ou)LED，原邊的(de)(de)光(guang)敏晶體管(guan)將處于(yu)發(fa)光(guang)狀(zhuang)態。U1的(de)(de)OPTO輸(shu)入(ru)引(yin)腳用(yong)于(yu)直接連(lian)接光(guang)敏晶體管(guan)，以(yi)極其簡單的(de)(de)方式(shi)構成閉合環(huan)路(lu)。光(guang)敏晶體管(guan)導(dao)通時(shi)(shi)，OPTO引(yin)腳被拉低(di)，內部比(bi)較(jiao)器(qi)在(zai)它的(de)(de)一個輸(shu)入(ru)端檢(jian)(jian)測到較(jiao)低(di)的(de)(de)電(dian)(dian)(dian)壓(ya)，比(bi)較(jiao)器(qi)的(de)(de)另一輸(shu)入(ru)電(dian)(dian)(dian)流(liu)檢(jian)(jian)測引(yin)腳(CS)的(de)(de)峰值電(dian)(dian)(dian)壓(ya)，OPTO引(yin)腳的(de)(de)低(di)電(dian)(dian)(dian)壓(ya)將在(zai)每個周(zhou)期直接限制功率MOSFETN1的(de)(de)峰值電(dian)(dian)(dian)流(liu)。由于(yu)U1是(shi)一個PWM控制器(qi)，電(dian)(dian)(dian)流(liu)限制使(shi)得電(dian)(dian)(dian)壓(ya)調(diao)節(jie)受作用(yong)在(zai)N1上的(de)(de)占空比(bi)(導(dao)通時(shi)(shi)間(jian)與斷開時(shi)(shi)間(jian)的(de)(de)比(bi)值)的(de)(de)影響，環(huan)路(lu)穩(wen)定性通過調(diao)節(jie)R11和C12來保證。R10和C5(連(lian)接在(zai)U3的(de)(de)第(di)(di)3和第(di)(di)4引(yin)腳)可消除(chu)穩(wen)定工作情況下的(de)(de)噪聲干(gan)擾。    

    U4的工作(zuo)特點(dian)    

    U4是一款用于單節Li+電池充電、功能完備的充電器，采用線性充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)模式，內置調整管(guan)和電(dian)(dian)(dian)(dian)(dian)流檢(jian)測電(dian)(dian)(dian)(dian)(dian)路。另外，它還集成了一個反向抑制二極管(guan)，在去掉輸入電(dian)(dian)(dian)(dian)(dian)源時(shi)可防(fang)止電(dian)(dian)(dian)(dian)(dian)池(chi)方向放(fang)電(dian)(dian)(dian)(dian)(dian)。接入一個深度放(fang)電(dian)(dian)(dian)(dian)(dian)的電(dian)(dian)(dian)(dian)(dian)池(chi)時(shi)，U4能(neng)夠檢(jian)測到低(di)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(低(di)于(yu)2.5V)，這樣(yang)，U4將首先啟動涓(juan)(juan)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)過程，在快充(chong)(chong)周(zhou)期的1/10時(shi)間(jian)段(duan)對電(dian)(dian)(dian)(dian)(dian)池(chi)進行涓(juan)(juan)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)，直到電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)上升(sheng)(sheng)到2.5V以上。在涓(juan)(juan)流充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)到快速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)轉換時(shi)，軟啟動電(dian)(dian)(dian)(dian)(dian)路迫使充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流在3ms時(shi)間(jian)內緩(huan)慢上升(sheng)(sheng)，避(bi)免較大的浪(lang)涌(yong)電(dian)(dian)(dian)(dian)(dian)流拉低(di)輸入電(dian)(dian)(dian)(dian)(dian)源。    

   上述(shu)功(gong)能的(de)實(shi)施(shi)不(bu)需要(yao)微控制器(qi)的(de)監(jian)管，而且，U4還具有可編(bian)程的(de)溫度(du)限制功(gong)能，我們會在下面(mian)就這一點進行詳細討(tao)論(lun)。用一個電(dian)(dian)(dian)阻設(she)置最大充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流，電(dian)(dian)(dian)阻兩端的(de)電(dian)(dian)(dian)壓與(yu)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流成正比，通過監(jian)視(shi)該電(dian)(dian)(dian)壓即可連(lian)續跟(gen)蹤充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流，更為復雜的(de)系統也可以(yi)采(cai)用ADC跟(gen)蹤監(jian)視(shi)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流。    

    Maxim還提供(gong)有另一款與(yu)MAX1507非常相似(si)的充電器―MAX1555，這(zhe)款IC能夠(gou)在沒有交流電源的情(qing)況(kuang)下從USB主機獲得充電電源。   

    電流調節(jie) 

    如果把Li+電(dian)(dian)(dian)(dian)(dian)池直接(jie)(jie)與一個低阻(zu)電(dian)(dian)(dian)(dian)(dian)壓源連(lian)接(jie)(jie)，充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流將不受(shou)任何限(xian)制，這種狀況會對電(dian)(dian)(dian)(dian)(dian)池及(ji)其周圍環(huan)境造成災(zai)難性(xing)的損(sun)害(hai)，從Li+電(dian)(dian)(dian)(dian)(dian)池的安全性(xing)考慮，必須(xu)將其充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流限(xian)制在額, 定(ding)范圍以內。U4根據連(lian)接(jie)(jie)在ISET(第5引腳)的電(dian)(dian)(dian)(dian)(dian)阻(zu)限(xian)制充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，圖1電(dian)(dian)(dian)(dian)(dian)路中選用了(le)一個1.87kΩ的電(dian)(dian)(dian)(dian)(dian)阻(zu)，將最大(da)電(dian)(dian)(dian)(dian)(dian)流設置在780mA: 

    Ifast=1461V/Rset=1461/1870≈780mA 

    電(dian)池(chi)電(dian)壓(ya)最小(xiao)時(shi)(shi)，由于(yu)輸入穩定在4.5V，U4輸入與輸出的(de)壓(ya)差(cha)最大(da)，如(ru)果此時(shi)(shi)電(dian)池(chi)是(shi)以最大(da)電(dian)流充電(dian)，U4功耗將達到最大(da)值。例如(ru)，假(jia)設電(dian)池(chi)電(dian)壓(ya)為2.5V，則對應的(de)功耗為：  

    P=IV=(0.78A)×(4.5V-2.5V)=1.56W 

    U4封裝(8引腳薄型DFN-EP，EP表示裸露焊盤)在溫度高達70℃時可以耗散的最大功率是1.951W，這樣，在整個電池電壓范圍內以780mA的電流充電應該沒有任何問題。但是，如果IC管芯由于較高的環境溫度或不良的散熱條件達到了70℃，U4內部的熱調節環路將自動降低充電電流，這一過程有別于其它充電IC中的“熱關斷”，“熱關斷”方式只是簡單地中止芯片中的所有電路工作，直到晶片溫度降至規定的數值。MAX1507所采用的方案能夠保證在芯片溫度不超出最大限制范圍的條件下提供最快的充電速率，隨著電池電壓的升高，充電電流在保持最高溫度的前提下逐漸升高，直到達到最大充電電流。在此之后，充電器在滿(man)足芯片溫度限制的條件下將以最大充(chong)電(dian)(dian)電(dian)(dian)流對電(dian)(dian)池(chi)充(chong)電(dian)(dian)，直到電(dian)(dian)池(chi)電(dian)(dian)壓達到內部設置的4.2V