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。     

    不同化(hua)學類型的電(dian)池對充電(dian)器的要(yao)求(qiu)   

    通常快(kuai)(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)比涓流(liu)(liu)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)更受歡迎，但快(kuai)(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)對(dui)電(dian)(dian)(dian)(dian)(dian)路的(de)(de)要(yao)求也(ye)復雜，鎳(nie)氫或鎳(nie)鎘(ge)電(dian)(dian)(dian)(dian)(dian)池的(de)(de)快(kuai)(kuai)速充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)技術與其它電(dian)(dian)(dian)(dian)(dian)池也(ye)是(shi)不同(tong)的(de)(de)。鎳(nie)鎘(ge)和(he)(he)鎳(nie)氫電(dian)(dian)(dian)(dian)(dian)池通常在(zai)(zai)恒(heng)流(liu)(liu)狀態(tai)下(xia)快(kuai)(kuai)充(chong)(chong)(chong)，而(er)(er)不是(shi)恒(heng)壓(ya)(ya)狀態(tai)下(xia)。快(kuai)(kuai)充(chong)(chong)(chong)終止檢測(ce)基于(yu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)(he)溫度的(de)(de)變化率，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)還應具備過(guo)壓(ya)(ya)保護(hu)和(he)(he)過(guo)熱保護(hu)功能(neng)。Li+和(he)(he)鉛(qian)酸電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)必須保證(zheng)作用到(dao)電(dian)(dian)(dian)(dian)(dian)池上的(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)(he)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)最大(da)值在(zai)(zai)規定的(de)(de)范圍內，當電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)維持在(zai)(zai)最大(da)單節電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)下(xia)降到(dao)一(yi)(yi)個較(jiao)低值時，充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)終止充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)。Li+和(he)(he)鉛(qian)酸電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)的(de)(de)區別(bie)在(zai)(zai)于(yu)所(suo)允許的(de)(de)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)、最大(da)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，另外鉛(qian)酸電(dian)(dian)(dian)(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)一(yi)(yi)般具有浮(fu)充(chong)(chong)(chong)能(neng)力(浮(fu)充(chong)(chong)(chong)是(shi)為了補(bu)充(chong)(chong)(chong)鉛(qian)酸電(dian)(dian)(dian)(dian)(dian)池的(de)(de)自放電(dian)(dian)(dian)(dian)(dian)，而(er)(er)對(dui)一(yi)(yi)個已經完(wan)全充(chong)(chong)(chong)滿的(de)(de)電(dian)(dian)(dian)(dian)(dian)池繼續輸入充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)(liu)的(de)(de)技術)，Li+電(dian)(dian)(dian)(dian)(dian)池的(de)(de)自放電(dian)(dian)(dian)(dian)(dian)非常低，所(suo)以不需要(yao)浮(fu)充(chong)(chong)(chong)。    

    Li+電池    

    為(wei)便攜式產品(pin)選擇電(dian)(dian)(dian)(dian)池(chi)時，最重(zhong)要(yao)的(de)(de)是高(gao)能量密度(du)、尺寸、重(zhong)量和(he)價格。迄今為(wei)止，Li+電(dian)(dian)(dian)(dian)池(chi)在最為(wei)流行的(de)(de)電(dian)(dian)(dian)(dian)池(chi)中能夠提供(gong)最高(gao)的(de)(de)體(ti)積和(he)能量密度(du)，但(dan)其(qi)每瓦時的(de)(de)成本也較(jiao)高(gao)。鉛酸(suan)電(dian)(dian)(dian)(dian)池(chi)的(de)(de)每瓦時成本最低，但(dan)比(bi)較(jiao)笨(ben)重(zhong)。本文以Li+電(dian)(dian)(dian)(dian)池(chi)為(wei)例(li)討論充電(dian)(dian)(dian)(dian)器的(de)(de)設計，它(ta)在便攜式產品(pin)中已經(jing)被普遍使用。我們選擇780mA的(de)(de)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流和(he)4.2V的(de)(de)終止電(dian)(dian)(dian)(dian)壓。 

 通用輸入交流電壓的離線式Li+電池充電器。    

    所(suo)示充電(dian)(dian)(dian)器無需微(wei)處理器干預，輸入電(dian)(dian)(dian)源可以采(cai)用全球范圍的(de)任何交流電(dian)(dian)(dian)源，省去(qu)了(le)(le)大(da)體積60Hz變壓器，而且可提供單節(jie)Li+電(dian)(dian)(dian)池所(suo)要求的(de)精確(que)的(de)充電(dian)(dian)(dian)電(dian)(dian)(dian)壓和(he)電(dian)(dian)(dian)流。充電(dian)(dian)(dian)器IC(U4)集成了(le)(le)全面的(de)保(bao)護功(gong)能(電(dian)(dian)(dian)壓、電(dian)(dian)(dian)流和(he)自保(bao)護)，確(que)保(bao)Li+電(dian)(dian)(dian)池的(de)安全充電(dian)(dian)(dian)。    

    假設Li+電(dian)(dian)池(chi)帶有過流、過壓(ya)和過熱保護(hu)，這些(xie)保護(hu)特性在(zai)(zai)電(dian)(dian)池(chi)包(bao)里是必需的，因為(wei)充(chong)電(dian)(dian)期間一旦電(dian)(dian)路(lu)出(chu)現故障，Li+電(dian)(dian)池(chi)將存(cun)在(zai)(zai)很大(da)的危險性，過流、過壓(ya)或(huo)溫(wen)度過高都有可能造(zao)成Li+電(dian)(dian)池(chi)爆炸。    

    電路(lu)描述     

    包括(kuo)兩顆(ke)主器(qi)件(U1和U4)、精密基準(zhun)(U3)和光耦(ou)(U2)。U1是(shi)離(li)線式(shi)開關控制器(qi)，配合隔(ge)離(li)變壓器(qi)、光耦(ou)和基準(zhun)產生隔(ge)離(li)的(de)穩壓直流(liu)輸(shu)出。直流(liu)電(dian)(dian)(dian)壓供給電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)器(qi)(U4)，U4提供電(dian)(dian)(dian)流(liu)限制、電(dian)(dian)(dian)壓調節、電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)和充(chong)電(dian)(dian)(dian)指示等功能。本方案(an)中，U4是(shi)一(yi)款簡單的(de)線性充(chong)電(dian)(dian)(dian)器(qi)，內置調整管，結合其(qi)熱控制環(huan)路提供快速充(chong)電(dian)(dian)(dian)。    

    MAX5022的特性(xing)     

    U1(MAX5022)在寬輸(shu)入范(fan)圍(wei)的應用中很容(rong)易設(she)計(ji)，本文(wen)所提供的方案(an)要求能夠滿足全球各地的交流(liu)電(dian)(dian)源規格，這里假設(she)通用的輸(shu)入電(dian)(dian)源電(dian)(dian)壓范(fan)圍(wei)為85VAC至265VAC。MAX5022的輸(shu)入范(fan)圍(wei)指標以及評估(gu)(gu)板電(dian)(dian)路的輸(shu)入范(fan)圍(wei)恰好(hao)滿足這一(yi)需(xu)求。對于所示(shi)充電(dian)(dian)器的電(dian)(dian)源端MAX5022評估(gu)(gu)板不需(xu)要作任何修改(gai)，隔離端只需(xu)對評估(gu)(gu)板的電(dian)(dian)阻值(zhi)稍(shao)作修改(gai)。    

    對(dui)于(yu)更(geng)大功率的(de)(de)應用，只需選(xuan)取(qu)(qu)功率較大的(de)(de)開關(guan)管(guan)和能(neng)夠(gou)處理更(geng)大功率的(de)(de)變壓器即可。圖1所示電(dian)(dian)路(lu)要(yao)求充(chong)電(dian)(dian)電(dian)(dian)流為(wei)(wei)780mA，最(zui)大電(dian)(dian)池(chi)電(dian)(dian)壓為(wei)(wei)4.2V。對(dui)充(chong)電(dian)(dian)電(dian)(dian)源(yuan)的(de)(de)要(yao)求與MAX5022評(ping)估(gu)板(ban)所提供的(de)(de)輸出(chu)相吻合：5V@1A，因(yin)此，不需要(yao)更(geng)換評(ping)估(gu)板(ban)的(de)(de)晶體管(guan)和變壓器。U4采(cai)用SOT23封裝，所以，充(chong)電(dian)(dian)器的(de)(de)尺寸在很(hen)大程度上取(qu)(qu)決(jue)于(yu)應用對(dui)充(chong)電(dian)(dian)電(dian)(dian)源(yuan)的(de)(de)需求。變壓器是電(dian)(dian)路(lu)中尺寸最(zui)大的(de)(de)元(yuan)件，由于(yu)開關(guan)控制器的(de)(de)工作頻率大于(yu)250kHz，允許(xu)系(xi)統選(xuan)用小尺寸的(de)(de)變壓器。     

    上電(dian)(dian)(dian)(dian)(dian)(dian)時，在開(kai)(kai)關控制器(qi)工作之前(qian)，U1調節器(qi)直接(jie)通過泄漏(lou)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)R1、R2從整流(liu)(liu)通路(lu)吸(xi)取少量的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，兩個電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)阻(zu)值(zhi)保證每個電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)上的(de)壓(ya)降不會(hui)超出(chu)每個電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)的(de)容限，Vin引(yin)腳(jiao)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不會(hui)超出(chu)其(qi)28V額定值(zhi)(30V為絕對最大值(zhi))，U1在輸入電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)達到24V時開(kai)(kai)始開(kai)(kai)關操作，并(bing)吸(xi)取更大的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(高于(yu)R1、R2所能(neng)提供(gong)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu))，在變壓(ya)器(qi)副邊線圈能(neng)夠(gou)提供(gong)足夠(gou)的(de)能(neng)量之前(qian)，額外的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)由Vin引(yin)腳(jiao)的(de)旁路(lu)電(dian)(dian)(dian)(dian)(dian)(dian)容供(gong)給。這種處(chu)理方式能(neng)夠(gou)適(shi)合較寬的(de)輸入電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)范圍，對效率的(de)影響也很小，這是(shi)因為在啟動過程中只需極小的(de)供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)(典型值(zhi)為50uA)。   

    為了防(fang)止U1的(de)(de)Vin引(yin)腳出現(xian)過壓(ya)(ya)(ya)，可以在Vin與地之間接一個26V至30V的(de)(de)齊納管，電壓(ya)(ya)(ya)值需要高于(yu)欠壓(ya)(ya)(ya)鎖存電壓(ya)(ya)(ya)的(de)(de)最大值，低于(yu)該(gai)引(yin)腳所(suo)允許(xu)的(de)(de)最大絕對電壓(ya)(ya)(ya)。如果器件沒有啟(qi)動正常(chang)的(de)(de)開關操作，則可認(ren)為電路(lu)發(fa)生了某些問題(ti)，所(suo)以，這(zhe)一保(bao)護措(cuo)施對于(yu)U1來說并(bing)不是必需的(de)(de)。     

    U1是一款(kuan)電流(liu)模式(shi)PWM控制器(qi)，具(ju)有逐周期限(xian)(xian)流(liu)電路(lu)，必(bi)要時其占空比可以(yi)提高(gao)到75%，非常(chang)適合圖1所示的反激拓撲。原(yuan)邊開(kai)關電流(liu)檢(jian)測采用尺寸為1206的1.78Ω電阻(R7)，該電阻限(xian)(xian)制了變壓器(qi)原(yuan)邊的最(zui)大電流(liu)。固定開(kai)關頻率(lv)和最(zui)大占空比限(xian)(xian)制使得最(zui)大限(xian)(xian)流(liu)具(ju)有輸出短(duan)路(lu)保(bao)護功能。   

    一旦短(duan)路輸(shu)出(chu)造成電路達到了上(shang)述限制條件，第三(san)組(zu)線圈(quan)將(jiang)無法提供10V以上(shang)的(de)電壓(UVLO的(de)低電壓門限)，U1將(jiang)再次(ci)進入啟動狀態，停止開關(guan)操作。短(duan)路故(gu)障(zhang)解除后系統會自動恢復正常(chang)的(de)工作狀態。   

    電壓調節   

    變壓(ya)(ya)器(qi)(qi)副邊的(de)(de)(de)電(dian)(dian)(dian)壓(ya)(ya)經過(guo)整流(liu)、濾波，然后(hou)由(you)R4、R5分壓(ya)(ya)在并聯型穩壓(ya)(ya)器(qi)(qi)U3的(de)(de)(de)調節(jie)點產(chan)生1.24V(對應于(yu)(yu)4.5V輸出)的(de)(de)(de)反(fan)饋電(dian)(dian)(dian)壓(ya)(ya)。為(wei)保證電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)器(qi)(qi)正(zheng)常工作，4.5V是最低電(dian)(dian)(dian)壓(ya)(ya)(包括容差)。因為(wei)充(chong)電(dian)(dian)(dian)器(qi)(qi)采用(yong)的(de)(de)(de)是線性結構，充(chong)電(dian)(dian)(dian)效率(lv)與輸入(ru)、輸出電(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)差值成反(fan)比，用(yong)最低電(dian)(dian)(dian)壓(ya)(ya)為(wei)充(chong)電(dian)(dian)(dian)器(qi)(qi)供電(dian)(dian)(dian)有助于(yu)(yu)降低功率(lv)損耗。   

    當調(diao)節點(dian)電(dian)壓高于(yu)1.24V時(shi)，并聯(lian)型穩壓器將(jiang)(jiang)(jiang)吸入電(dian)流(liu)，導(dao)通(tong)光(guang)耦LED，原(yuan)邊的(de)(de)(de)(de)(de)(de)光(guang)敏晶體(ti)管將(jiang)(jiang)(jiang)處于(yu)發光(guang)狀態。U1的(de)(de)(de)(de)(de)(de)OPTO輸入引腳用于(yu)直(zhi)接(jie)連接(jie)光(guang)敏晶體(ti)管，以(yi)極其簡單的(de)(de)(de)(de)(de)(de)方式構(gou)成閉合環路。光(guang)敏晶體(ti)管導(dao)通(tong)時(shi)，OPTO引腳被拉低(di)，內(nei)部比(bi)較(jiao)(jiao)器在它的(de)(de)(de)(de)(de)(de)一(yi)個輸入端檢(jian)測(ce)到較(jiao)(jiao)低(di)的(de)(de)(de)(de)(de)(de)電(dian)壓，比(bi)較(jiao)(jiao)器的(de)(de)(de)(de)(de)(de)另一(yi)輸入電(dian)流(liu)檢(jian)測(ce)引腳(CS)的(de)(de)(de)(de)(de)(de)峰值(zhi)電(dian)壓，OPTO引腳的(de)(de)(de)(de)(de)(de)低(di)電(dian)壓將(jiang)(jiang)(jiang)在每個周期直(zhi)接(jie)限(xian)制(zhi)功率MOSFETN1的(de)(de)(de)(de)(de)(de)峰值(zhi)電(dian)流(liu)。由于(yu)U1是一(yi)個PWM控制(zhi)器，電(dian)流(liu)限(xian)制(zhi)使(shi)得(de)電(dian)壓調(diao)節受作(zuo)用在N1上(shang)的(de)(de)(de)(de)(de)(de)占(zhan)空比(bi)(導(dao)通(tong)時(shi)間與斷(duan)開(kai)時(shi)間的(de)(de)(de)(de)(de)(de)比(bi)值(zhi))的(de)(de)(de)(de)(de)(de)影(ying)響，環路穩定性通(tong)過調(diao)節R11和C12來保證。R10和C5(連接(jie)在U3的(de)(de)(de)(de)(de)(de)第(di)(di)3和第(di)(di)4引腳)可消(xiao)除穩定工作(zuo)情(qing)況下(xia)的(de)(de)(de)(de)(de)(de)噪(zao)聲干擾。    

    U4的(de)工作特點(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)模式，內(nei)置(zhi)調(diao)整管和電(dian)(dian)流(liu)檢測電(dian)(dian)路。另外，它還集成了(le)一(yi)個反(fan)向抑制二極管，在去掉輸入(ru)電(dian)(dian)源(yuan)時(shi)(shi)可防止電(dian)(dian)池方向放(fang)電(dian)(dian)。接入(ru)一(yi)個深度放(fang)電(dian)(dian)的電(dian)(dian)池時(shi)(shi)，U4能(neng)夠檢測到(dao)低(di)電(dian)(dian)池電(dian)(dian)壓(ya)(低(di)于2.5V)，這樣，U4將首先(xian)啟(qi)動涓流(liu)充(chong)(chong)電(dian)(dian)過程，在快(kuai)充(chong)(chong)周期的1/10時(shi)(shi)間(jian)(jian)段對電(dian)(dian)池進行(xing)涓流(liu)充(chong)(chong)電(dian)(dian)，直到(dao)電(dian)(dian)池電(dian)(dian)壓(ya)上(shang)(shang)(shang)升到(dao)2.5V以上(shang)(shang)(shang)。在涓流(liu)充(chong)(chong)電(dian)(dian)到(dao)快(kuai)速充(chong)(chong)電(dian)(dian)轉換時(shi)(shi)，軟(ruan)啟(qi)動電(dian)(dian)路迫使(shi)充(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)在3ms時(shi)(shi)間(jian)(jian)內(nei)緩慢(man)上(shang)(shang)(shang)升，避免較(jiao)大的浪涌電(dian)(dian)流(liu)拉低(di)輸入(ru)電(dian)(dian)源(yuan)。    

   上述功能(neng)的(de)實施不需(xu)要微控(kong)制(zhi)器(qi)的(de)監(jian)管，而且，U4還具(ju)有可(ke)編程的(de)溫(wen)度限制(zhi)功能(neng)，我們會在下面就這一(yi)點進(jin)行詳細討(tao)論。用(yong)一(yi)個電阻設置最大(da)充(chong)電電流(liu)(liu)，電阻兩端的(de)電壓(ya)與充(chong)電電流(liu)(liu)成正(zheng)比，通過監(jian)視該(gai)電壓(ya)即可(ke)連續跟蹤(zong)充(chong)電電流(liu)(liu)，更為復雜(za)的(de)系(xi)統也(ye)可(ke)以采用(yong)ADC跟蹤(zong)監(jian)視充(chong)電電流(liu)(liu)。    

    Maxim還(huan)提供(gong)有(you)另一款(kuan)與MAX1507非常(chang)相似(si)的充電器―MAX1555，這款(kuan)IC能夠在沒有(you)交流(liu)電源的情(qing)況下(xia)從USB主(zhu)機獲得充電電源。   

    電(dian)流調節 

    如果把Li+電(dian)(dian)(dian)池直接(jie)與一(yi)(yi)個(ge)低阻電(dian)(dian)(dian)壓源連接(jie)，充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)將不受(shou)任何(he)限(xian)制(zhi)，這種狀況(kuang)會對電(dian)(dian)(dian)池及(ji)其周(zhou)圍(wei)環(huan)境造成災難性(xing)的(de)(de)損(sun)害(hai)，從(cong)Li+電(dian)(dian)(dian)池的(de)(de)安全性(xing)考慮，必須將其充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)限(xian)制(zhi)在額, 定范圍(wei)以內。U4根據連接(jie)在ISET(第(di)5引腳)的(de)(de)電(dian)(dian)(dian)阻限(xian)制(zhi)充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)，圖1電(dian)(dian)(dian)路中選用(yong)了一(yi)(yi)個(ge)1.87kΩ的(de)(de)電(dian)(dian)(dian)阻，將最(zui)大(da)電(dian)(dian)(dian)流(liu)設置在780mA: 

    Ifast=1461V/Rset=1461/1870≈780mA 

    電(dian)(dian)池電(dian)(dian)壓最(zui)小時，由于輸入(ru)穩定(ding)在4.5V，U4輸入(ru)與輸出的(de)壓差最(zui)大(da)(da)，如果(guo)此時電(dian)(dian)池是(shi)以最(zui)大(da)(da)電(dian)(dian)流充電(dian)(dian)，U4功(gong)耗將達到最(zui)大(da)(da)值。例如，假設電(dian)(dian)池電(dian)(dian)壓為(wei)2.5V，則對應(ying)的(de)功(gong)耗為(wei)：  

    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，充電器在滿足芯片溫度限制的條件下將以最大充(chong)電(dian)電(dian)流對電(dian)池充(chong)電(dian)，直到電(dian)池電(dian)壓達到內部(bu)設置的4.2V