1、近十年來(lai)，隨著(zhu)各種便攜(xie)式(shi)設備（如手機(ji)、筆記本電(dian)(dian)腦 、攝像機(ji) 、數碼相機(ji) 、PDA 等）的不斷推出 ，對電(dian)(dian)池(chi)的要求也隨之提高(gao)。以(yi)前，在(zai)這(zhe)類應(ying)用中 ，NiMH電(dian)(dian)池(chi)和NiCD電(dian)(dian)池(chi)，以(yi)其低(di)價格占有較(jiao)大(da)優勢；但隨著(zhu)便攜(xie)式(shi)設備對體積/重量的要求越來(lai)越苛刻，工作和待機(ji)時間(jian)越來(lai)越長(chang)以(yi)及Li電(dian)(dian)池(chi)成本的不斷降(jiang)低(di)，使(shi) Li電(dian)(dian)池(chi)的優勢性能(neng)在(zai)這(zhe)類應(ying)用中得(de)以(yi)充(chong)分的展示(shi)，被廣大(da)電(dian)(dian)子設計工程師和消費者所接(jie)受。隨著(zhu)Li電(dian)(dian)池(chi)性能(neng)的不斷提高(gao)和成本的進一步降(jiang)低(di) ，Li電(dian)(dian)池(chi)將在(zai)許多應(ying)用中取代NiCD和NiMH電(dian)(dian)池(chi) 。

　　雖然鋰(li)離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)有(you)(you)以(yi)上種種優點(dian)和良好的(de)市場前景，但它對充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)要(yao)(yao)求比較高，在(zai)(zai)使(shi)用過程中要(yao)(yao)避免出(chu)現(xian)過充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)和過放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)現(xian)象。鋰(li)離(li)子電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)過程如(ru)(ru)圖(tu)１所(suo)示，在(zai)(zai)一(yi)(yi)個充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)周期內，鋰(li)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)在(zai)(zai)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)開(kai)始之前需要(yao)(yao)檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓和溫(wen)度(du)，判斷是否(fou)可充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，如(ru)(ru)果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓或溫(wen)度(du)超(chao)出(chu)允許(xu)范圍，則禁止(zhi)(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)允許(xu)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓為2.5-4.2V，溫(wen)度(du)為2.5-50℃。在(zai)(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)處于深(shen)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)情況下(xia)，必須要(yao)(yao)求充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器具有(you)(you)預充(chong)(chong)(chong)(chong)(chong)(chong)過程，使(shi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)滿(man)足快(kuai)速(su)(su)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)條件，然后根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)廠商(shang)推薦的(de)快(kuai)速(su)(su)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速(su)(su)度(du)對電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)進行恒流充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓緩慢上升(sheng)；一(yi)(yi)旦電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓達到所(suo)設定(ding)的(de)終止(zhi)(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓（一(yi)(yi)般為 4.1V 或4.2V），恒流充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)終止(zhi)(zhi)(zhi)，充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流快(kuai)速(su)(su)衰減，充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)進入(ru)滿(man)充(chong)(chong)(chong)(chong)(chong)(chong)過程；在(zai)(zai)滿(man)充(chong)(chong)(chong)(chong)(chong)(chong)過程中，充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流逐(zhu)漸衰減，直到滿(man)充(chong)(chong)(chong)(chong)(chong)(chong)時(shi)間超(chao)時(shi)，轉入(ru)頂端(duan)截(jie)止(zhi)(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)；頂端(duan)截(jie)止(zhi)(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器以(yi)極小的(de)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流為電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)補(bu)充(chong)(chong)(chong)(chong)(chong)(chong)能量；頂端(duan)截(jie)止(zhi)(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)一(yi)(yi)段時(shi)間后，關閉充(chong)(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

2　MAX1501簡介
　　
　　MAXIM公(gong)司的MAX1501是(shi)一種全(quan)新的溫度調節(jie)線(xian)性充電(dian)器采用16引(yin)腳TQFN封裝(zhuang)，可(ke)為(wei)鋰離子、鎳鎘、鎳氫電(dian)池(chi)進行充電(dian).MAX1501的特(te)點及(ji)其引(yin)腳功(gong)能(neng)。它具有(you)如下特(te)點：

　　1.獨立(li)運行或由微(wei)處理器控制的線性充電方案；

　　2.輸入(ru)大于(yu)6.5v時充(chong)電停(ting)止；

　　3.電(dian)流檢測監視器輸(shu)出；

　　4.電池電壓下降4v以下后自動啟動充電；

　　5.無電池(chi)時仍(reng)然(ran)保持穩(wen)定輸出(chu)；

　　6.集成了PMOSFET.反向(xiang)阻斷二極管和檢測電流電阻；

　　7.薄型QFN封裝(zhuang)的多化學類型充(chong)電器。

3　MAX1501引腳功能

　　INP：高電(dian)流充電(dian)輸入；

　　IN: 低(di)電流充(chong)電輸入(ru)；

　　GND： 地.連接(jie)外部開關到地；

　　SETI：電(dian)流傳感跨導(dao)放(fang)大輸(shu)出(chu)；

　　VL： 線性(xing)輸出調整器；

　　TMAX： 輸(shu)入最大(da)充電(dian)時間選(xuan)擇(僅對max1501)；

　　IC：　 MAX1501Z的(de)內(nei)部(bu)連接.隨(sui)浮動；

　　FULLI： 最大關閉電(dian)流(liu)選擇輸入；

　　TEMP：衰耗溫度選擇輸入；
　　

4　鋰離子電池充電器的研制

　　MAX1501的(de)(de)最典(dian)型的(de)(de)應用(yong)是(shi)能夠用(yong)10%的(de)(de)快(kuai)速充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)對鋰(li)離子(zi)電(dian)(dian)(dian)(dian)(dian)池(chi)進(jin)行預充(chong)電(dian)(dian)(dian)(dian)(dian)，用(yong)一(yi)個(ge)軟啟動(dong)系統持續(xu)增(zeng)加充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)。以每20ms增(zeng)加10%直到(dao)(dao)電(dian)(dian)(dian)(dian)(dian)壓達到(dao)(dao)2.8V，當電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓達到(dao)(dao)規格電(dian)(dian)(dian)(dian)(dian)壓4.1V/4.2V時進(jin)入常壓狀態并(bing)且減少充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)。在SETI與(yu)地之間(jian)設置一(yi)個(ge)晶體管(guan)來控制快(kuai)速充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)，并(bing)且通(tong)過(guo)減少輸入電(dian)(dian)(dian)(dian)(dian)流(liu)使MAX1501遠(yuan)離過(guo)熱，溫度(du)(du)調(diao)節(jie)電(dian)(dian)(dian)(dian)(dian)路調(diao)節(jie)MAX1501的(de)(de)溫度(du)(du)。當到(dao)(dao)達頂端關斷電(dian)(dian)(dian)(dian)(dian)流(liu)的(de)(de)關斷值時RLED腳作(zuo)用(yong)一(yi)個(ge)高阻抗

進入低(di)維護狀(zhuang)態。 當電池電壓(ya)低(di)與95%時(shi)，通(tong)過設置SELV可以自(zi)動進行在(zai)充(chong)電。

　　（1）設置充電(dian)電(dian)流(liu)

　　設定電阻充電電流根(gen)據下列公式

　　（2）設置電(dian)容

　　為了獲得合(he)適(shi)的穩定性，可(ke)以用(yong)一(yi)個陶(tao)(tao)瓷電(dian)(dian)容(rong)(rong)最(zui)常用(yong)10uF 5R陶(tao)(tao)瓷電(dian)(dian)容(rong)(rong)來連接(jie)BATT到GND。將IN和INP連接(jie)起來并且到GND用(yong)1uF的陶(tao)(tao)瓷電(dian)(dian)容(rong)(rong)。由(you)于過(guo)高(gao)輸(shu)入電(dian)(dian)壓或(huo)過(guo)高(gao)充(chong)電(dian)(dian)電(dian)(dian)流，可(ke)用(yong)更大的輸(shu)入途徑(jing)電(dian)(dian)容(rong)(rong)來降低噪聲。

　　（3）設置(zhi)溫度調節

　　在(zai)邏輯輸入條件下(xia)設置規(gui)則的(de)(de)死(si)機(ji)溫度(du)，MAX1501通過降低充電電流(liu)來(lai)限制由TEMP設定的(de)(de)死(si)機(ji)溫度(du)值。MAX1501運(yun)行正(zheng)常，溫度(du)環路不(bu)會顯示(shi)異常情況。TEMP允(yun)許在(zai)提供過多的(de)(de)能量(liang)損(sun)失(shi)的(de)(de)保(bao)護的(de)(de)前提下(xia)將充電電流(liu)擴展(zhan)到最(zui)大限度(du)。

　　（4）設置充(chong)電時間

　　在TMAX邏(luo)輯(ji)輸入條件下設置(zhi)最(zui)(zui)(zui)大(da)充(chong)電(dian)(dian)時間(jian)。TMAX限制充(chong)電(dian)(dian)周期用來保護電(dian)(dian)池充(chong)電(dian)(dian)過長(chang)。將(jiang)(jiang)TMAX與GND連接起(qi)來可將(jiang)(jiang)最(zui)(zui)(zui)長(chang)充(chong)電(dian)(dian)時間(jian)設置(zhi)為(wei)三小時。將(jiang)(jiang)TMAX懸空可將(jiang)(jiang)最(zui)(zui)(zui)大(da)充(chong)電(dian)(dian)時間(jian)設置(zhi)為(wei)4.5小時。將(jiang)(jiang)TMAX和VL連接起(qi)來可將(jiang)(jiang)最(zui)(zui)(zui)長(chang)充(chong)電(dian)(dian)時間(jian)設置(zhi)為(wei)6小時。

　　（5）綜述討論

　　MAX1501和一個微處理器相(xiang)結合(he)從而決定它有(you)(you)很好的充(chong)(chong)電方(fang)案專用(yong)的熱(re)調節電路用(yong)來限制電路節點溫度(du)，當快(kuai)速充(chong)(chong)電或當環境溫度(du)很高的時(shi)候確保(bao)最大充(chong)(chong)電電流不會損壞充(chong)(chong)電器，在(zai)沒有(you)(you)電池(chi)的情況下MAX1501提供(gong)(gong)可調節的輸(shu)出電壓(ya)，在(zai)允(yun)許電池(chi)充(chong)(chong)電的情況下這個裝置有(you)(you)較高的適應性, 安全時(shi)間內可以提供(gong)(gong)一個可調整(zheng)的快(kuai)速充(chong)(chong)電電流,頂端(duan)關斷電流,.并且有(you)(you)熱(re)量方(fang)嵌條調整(zheng)點.其它特(te)點包括輸(shu)入電量檢測

并(bing)且有輸入(ru)低的過(guo)壓(ya)保護和規定了(le)較低的控制輸入(ru).MAX1501能(neng)夠(gou)接受一(yi)個(ge)4.5V到13V的電(dian)壓(ya)供電(dian).但是(shi)當輸入(ru)電(dian)壓(ya)超過(guo)6.5伏時為了(le)防止(zhi)過(guo)多的能(neng)量消耗MAX1501充電(dian)停止(zhi).MAX1501擴(kuo)大了(le)溫度范圍(-40°C to +85°C)并(bing)且體積也減小了(le).

5　結束語

　　本文介紹了一種采用ＭＡＸ1501 充電控制芯片設計的簡單實用的鋰離子電池充電器，最后對(dui)電(dian)路的特性及充電(dian)參數的設置(zhi)進行了分析(xi)。