1、近十年來，隨著各種便(bian)攜式(shi)(shi)設備(bei)（如手機(ji)、筆記本(ben)電(dian)腦 、攝像機(ji) 、數碼相機(ji) 、PDA 等）的(de)不(bu)斷推出 ，對電(dian)池(chi)(chi)的(de)要求(qiu)也(ye)隨之提高。以(yi)(yi)前，在這(zhe)類應(ying)(ying)用中(zhong) ，NiMH電(dian)池(chi)(chi)和(he)NiCD電(dian)池(chi)(chi)，以(yi)(yi)其(qi)低價(jia)格(ge)占(zhan)有較大優勢；但隨著便(bian)攜式(shi)(shi)設備(bei)對體積(ji)/重量(liang)的(de)要求(qiu)越來越苛刻，工作和(he)待(dai)機(ji)時(shi)間越來越長以(yi)(yi)及Li電(dian)池(chi)(chi)成本(ben)的(de)不(bu)斷降低，使 Li電(dian)池(chi)(chi)的(de)優勢性(xing)能在這(zhe)類應(ying)(ying)用中(zhong)得以(yi)(yi)充(chong)分(fen)的(de)展示，被廣大電(dian)子(zi)設計工程師和(he)消(xiao)費者(zhe)所接受。隨著Li電(dian)池(chi)(chi)性(xing)能的(de)不(bu)斷提高和(he)成本(ben)的(de)進一步降低 ，Li電(dian)池(chi)(chi)將在許多(duo)應(ying)(ying)用中(zhong)取(qu)代NiCD和(he)NiMH電(dian)池(chi)(chi) 。

　　雖然鋰離(li)子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)有以上(shang)種種優點(dian)和(he)(he)(he)良(liang)好(hao)的(de)市場前景，但它對(dui)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)要求(qiu)比較高，在使用過(guo)程(cheng)中要避免(mian)出現過(guo)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)和(he)(he)(he)過(guo)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)現象(xiang)。鋰離(li)子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)過(guo)程(cheng)如(ru)圖１所示，在一個充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)周期內，鋰電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)在充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)開(kai)始之前需要檢測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)和(he)(he)(he)溫度(du)(du)，判斷是(shi)否可充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，如(ru)果電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)或(huo)溫度(du)(du)超(chao)出允許范圍(wei)，則禁(jin)止(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。每節電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的(de)允許充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)為(wei)2.5-4.2V，溫度(du)(du)為(wei)2.5-50℃。在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)處(chu)于深放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)情況下，必須要求(qiu)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器具有預充(chong)(chong)(chong)(chong)(chong)過(guo)程(cheng)，使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)滿足(zu)快速充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)條件，然后(hou)根據電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)廠商推薦的(de)快速充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)速度(du)(du)對(dui)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)進(jin)行(xing)恒流充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)緩慢上(shang)升；一旦電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)達到(dao)所設(she)定的(de)終(zhong)止(zhi)(zhi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)(ya)（一般為(wei) 4.1V 或(huo)4.2V），恒流充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)終(zhong)止(zhi)(zhi)，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流快速衰減(jian)，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)進(jin)入滿充(chong)(chong)(chong)(chong)(chong)過(guo)程(cheng)；在滿充(chong)(chong)(chong)(chong)(chong)過(guo)程(cheng)中，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流逐漸(jian)衰減(jian)，直到(dao)滿充(chong)(chong)(chong)(chong)(chong)時(shi)間(jian)超(chao)時(shi)，轉入頂端(duan)截止(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)；頂端(duan)截止(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)器以極小的(de)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流為(wei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)補(bu)充(chong)(chong)(chong)(chong)(chong)能量；頂端(duan)截止(zhi)(zhi)充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)一段時(shi)間(jian)后(hou)，關閉充(chong)(chong)(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)。

2　MAX1501簡介
　　
　　MAXIM公司的(de)(de)MAX1501是一種全新的(de)(de)溫度調節線性充(chong)電器采用16引腳TQFN封裝，可為鋰(li)離(li)子、鎳鎘(ge)、鎳氫電池進(jin)行充(chong)電.MAX1501的(de)(de)特點(dian)及其引腳功能。它具有(you)如下特點(dian)：

　　1.獨立運行或由(you)微處(chu)理器控制的線性充(chong)電方案；

　　2.輸入(ru)大于6.5v時充電停止；

　　3.電流檢(jian)測監視器(qi)輸出；

　　4.電(dian)池電(dian)壓下降4v以下后自動(dong)啟動(dong)充電(dian)；

　　5.無電池時(shi)仍(reng)然(ran)保持(chi)穩定輸出(chu)；

　　6.集成了PMOSFET.反(fan)向阻(zu)斷(duan)二(er)極管和(he)檢測電流電阻(zu)；

　　7.薄(bo)型(xing)QFN封裝(zhuang)的多化學類型(xing)充電器(qi)。

3　MAX1501引(yin)腳功能

　　INP：高電(dian)流充電(dian)輸入；

　　IN: 低電流充電輸(shu)入(ru)；

　　GND： 地(di)(di).連(lian)接外部開關到地(di)(di)；

　　SETI：電流傳感跨(kua)導放大輸出；

　　VL： 線性(xing)輸出調整器；

　　TMAX： 輸入最大充電(dian)時間選擇(僅對max1501)；

　　IC：　 MAX1501Z的內部連接(jie).隨浮動；

　　FULLI： 最大(da)關閉電流選(xuan)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)最典型(xing)的(de)(de)應用是(shi)能夠用10%的(de)(de)快(kuai)速充(chong)電(dian)(dian)電(dian)(dian)流對鋰離子(zi)電(dian)(dian)池(chi)(chi)進行預充(chong)電(dian)(dian)，用一(yi)個(ge)軟啟動(dong)系統(tong)持續增(zeng)加(jia)充(chong)電(dian)(dian)電(dian)(dian)流。以每20ms增(zeng)加(jia)10%直到電(dian)(dian)壓(ya)(ya)達到2.8V，當(dang)電(dian)(dian)池(chi)(chi)電(dian)(dian)壓(ya)(ya)達到規格電(dian)(dian)壓(ya)(ya)4.1V/4.2V時進入常壓(ya)(ya)狀態并(bing)且(qie)減少(shao)(shao)充(chong)電(dian)(dian)電(dian)(dian)流。在SETI與地之間設置一(yi)個(ge)晶體管來控(kong)制快(kuai)速充(chong)電(dian)(dian)電(dian)(dian)流，并(bing)且(qie)通過(guo)減少(shao)(shao)輸入電(dian)(dian)流使MAX1501遠離過(guo)熱，溫度(du)調節(jie)電(dian)(dian)路調節(jie)MAX1501的(de)(de)溫度(du)。當(dang)到達頂端關斷電(dian)(dian)流的(de)(de)關斷值時RLED腳作用一(yi)個(ge)高(gao)阻抗(kang)

進入低(di)維護狀態。 當(dang)電(dian)池電(dian)壓低(di)與95%時，通過(guo)設置SELV可以自動進行在充電(dian)。

　　（1）設置(zhi)充電電流

　　設定電(dian)(dian)阻充電(dian)(dian)電(dian)(dian)流根(gen)據下列公式

　　（2）設置電容(rong)

　　為了獲得合適的(de)(de)穩定性(xing)，可以用一個陶瓷電(dian)容(rong)(rong)(rong)最常用10uF 5R陶瓷電(dian)容(rong)(rong)(rong)來連接BATT到(dao)GND。將(jiang)IN和INP連接起(qi)來并且到(dao)GND用1uF的(de)(de)陶瓷電(dian)容(rong)(rong)(rong)。由于過高輸(shu)入電(dian)壓(ya)或過高充(chong)電(dian)電(dian)流，可用更大的(de)(de)輸(shu)入途徑電(dian)容(rong)(rong)(rong)來降低(di)噪聲。

　　（3）設置溫度調節

　　在邏輯輸入條(tiao)件(jian)下設置規則的(de)(de)死機(ji)溫度，MAX1501通過(guo)(guo)降低充電電流(liu)來(lai)限制由TEMP設定的(de)(de)死機(ji)溫度值(zhi)。MAX1501運行正常，溫度環路(lu)不會顯示異常情(qing)況。TEMP允許在提供(gong)過(guo)(guo)多的(de)(de)能量損(sun)失(shi)的(de)(de)保護的(de)(de)前提下將充電電流(liu)擴(kuo)展到最大限度。

　　（4）設置充電時間

　　在(zai)TMAX邏(luo)輯(ji)輸入條件下(xia)設(she)置(zhi)最大充(chong)電(dian)時(shi)(shi)間(jian)(jian)。TMAX限制充(chong)電(dian)周期用來(lai)保護電(dian)池充(chong)電(dian)過長。將TMAX與GND連(lian)接起(qi)來(lai)可將最長充(chong)電(dian)時(shi)(shi)間(jian)(jian)設(she)置(zhi)為(wei)三(san)小(xiao)時(shi)(shi)。將TMAX懸空可將最大充(chong)電(dian)時(shi)(shi)間(jian)(jian)設(she)置(zhi)為(wei)4.5小(xiao)時(shi)(shi)。將TMAX和VL連(lian)接起(qi)來(lai)可將最長充(chong)電(dian)時(shi)(shi)間(jian)(jian)設(she)置(zhi)為(wei)6小(xiao)時(shi)(shi)。

　　（5）綜述討論

　　MAX1501和一個微(wei)處理器相結(jie)合從而決定它有(you)(you)很好的(de)充電(dian)(dian)方(fang)(fang)案專用(yong)的(de)熱調節電(dian)(dian)路用(yong)來限制電(dian)(dian)路節點(dian)溫度(du)，當(dang)快(kuai)速充電(dian)(dian)或當(dang)環境(jing)溫度(du)很高的(de)時候確保最(zui)大充電(dian)(dian)電(dian)(dian)流不(bu)會損壞充電(dian)(dian)器，在(zai)沒有(you)(you)電(dian)(dian)池的(de)情況(kuang)下(xia)MAX1501提供可調節的(de)輸出(chu)電(dian)(dian)壓，在(zai)允許電(dian)(dian)池充電(dian)(dian)的(de)情況(kuang)下(xia)這(zhe)個裝置有(you)(you)較高的(de)適應性, 安全時間內可以提供一個可調整(zheng)的(de)快(kuai)速充電(dian)(dian)電(dian)(dian)流,頂端關斷電(dian)(dian)流,.并且(qie)有(you)(you)熱量方(fang)(fang)嵌條(tiao)調整(zheng)點(dian).其它特點(dian)包括輸入電(dian)(dian)量檢測

并(bing)且有輸入低的(de)(de)過(guo)壓(ya)保護和規定了較(jiao)低的(de)(de)控(kong)制輸入.MAX1501能(neng)夠接(jie)受一個4.5V到(dao)13V的(de)(de)電壓(ya)供電.但是(shi)當輸入電壓(ya)超過(guo)6.5伏時為(wei)了防止(zhi)過(guo)多的(de)(de)能(neng)量消耗MAX1501充電停止(zhi).MAX1501擴大了溫度范圍(-40°C to +85°C)并(bing)且體積也(ye)減小了.

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(hou)對電(dian)路(lu)的(de)特性(xing)及充(chong)電(dian)參數的(de)設置進行了(le)分析。