如今的(de)(de)便(bian)攜式(shi)(shi)(shi)電(dian)(dian)(dian)子(zi)(zi)備(bei)中電(dian)(dian)(dian)池技(ji)術包括電(dian)(dian)(dian)量檢測(ce)算(suan)法、電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)算(suan)法與(yu)(yu)電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)技(ji)術等幾個方面。眾所周(zhou)知(zhi),充(chong)電(dian)(dian)(dian)式(shi)(shi)(shi)電(dian)(dian)(dian)池化學反應(ying)有(you)鎳鎘、鎳氫、鋰(li)離子(zi)(zi)和鋰(li)聚合物(wu)4種程式(shi)(shi)(shi),作(zuo)為(wei)便(bian)攜式(shi)(shi)(shi)電(dian)(dian)(dian)子(zi)(zi)設備(bei)來說(shuo),雖然這4種電(dian)(dian)(dian)池程式(shi)(shi)(shi)各有(you)特點,但從(cong)能量密度與(yu)(yu)安全性角度的(de)(de)發展與(yu)(yu)實踐可知(zhi), 鋰(li)離子(zi)(zi)電(dian)(dian)(dian)池和鋰(li)聚合物(wu)電(dian)(dian)(dian)池的(de)(de)優勢己成為(wei)小(xiao)型長運行時間的(de)(de)設備(bei)的(de)(de)理想之選，比如筆記本電(dian)(dian)(dian)腦以(yi)及基于(yu)硬盤的(de)(de)PMP等.對便(bian)攜式(shi)(shi)(shi)電(dian)(dian)(dian)子(zi)(zi)備(bei)工程師(shi)來說(shuo)，正確(que)選擇與(yu)(yu)應(ying)用(yong)好便(bian)攜式(shi)(shi)(shi)電(dian)(dian)(dian)子(zi)(zi)備(bei)中電(dian)(dian)(dian)池技(ji)術至關重要,值此本文將對此作(zuo)研討,并作(zuo)應(ying)用(yong)舉例分(fen)析(xi).

1、關(guan)于細流充(chong)(chong)電(dian)、快速充(chong)(chong)電(dian)和穩定充(chong)(chong)電(dian)的電(dian)池充(chong)(chong)電(dian)算法

根據(ju)最(zui)終應用(yong)的能量需求，一個(ge)電(dian)池組可能包(bao)含最(zui)多4個(ge)鋰(li)離(li)子或鋰(li)聚合物(wu)電(dian)池芯(xin),其配置可有(you)多種變化(hua)，同時(shi)帶(dai)有(you)一個(ge)主流的電(dian)源適配器(qi)：直接的適配器(qi)、USB接口或汽車充(chong)(chong)(chong)電(dian)器(qi)。除(chu)去電(dian)芯(xin)數量、電(dian)芯(xin)的配置或電(dian)源適配器(qi)類型上的差別，這些電(dian)池組都有(you)同樣(yang)(yang)的充(chong)(chong)(chong)電(dian)特(te)性。因(yin)此它們(men)的充(chong)(chong)(chong)電(dian)算法也(ye)一樣(yang)(yang)。鋰(li)離(li)子與鋰(li)聚合物(wu)電(dian)池最(zui)好的充(chong)(chong)(chong)電(dian)算法可以(yi)分(fen)為3個(ge)階段：細流充(chong)(chong)(chong)電(dian)、快速充(chong)(chong)(chong)電(dian)和穩定(ding)充(chong)(chong)(chong)電(dian)。

*細流充電.用于對深度放電的電芯進行充電。當電芯電壓在低于大約2.8V時，用一個恒定的0.1C的電流為它充電。
*快速充電.電芯電壓超過細流充電的門檻時，提高充電電流進行快速充電。快速充電電流應低于1.0C。
*穩定電(dian)壓(ya)(ya)。在快速充電(dian)過程中(zhong)，一(yi)旦電(dian)芯電(dian)壓(ya)(ya)達(da)到4.2V，穩定電(dian)壓(ya)(ya)階段(duan)就開(kai)始了(le)。這(zhe)時(shi)(shi)可通(tong)過最小(xiao)(xiao)充電(dian)電(dian)流(liu)或(huo)定時(shi)(shi)器或(huo)這(zhe)兩(liang)者的聯合(he)來(lai)中(zhong)斷充電(dian).當最小(xiao)(xiao)電(dian)流(liu)低于大約0.07C時(shi)(shi)，可中(zhong)斷充電(dian)。定時(shi)(shi)器則要靠一(yi)個預(yu)設的定時(shi)(shi)器來(lai)觸發中(zhong)斷。

高級的電池充電器通(tong)常帶有附加的(de)安(an)全功能。比如，如果電(dian)(dian)芯溫度超出給定窗口(kou)，通(tong)常是(shi)(shi)0℃--45℃，充(chong)電(dian)(dian)就會暫停。除去某些非常低端(duan)的(de)設備，現在(zai)市面上的(de)鋰離子／鋰聚合(he)物電(dian)(dian)池充(chong)電(dian)(dian)方(fang)案都(dou)集成或是(shi)(shi)帶有外置的(de)元件，以便按照充(chong)電(dian)(dian)特性進行充(chong)電(dian)(dian)，這(zhe)不(bu)光是(shi)(shi)為了取(qu)得(de)更佳充(chong)電(dian)(dian)效果，同時(shi)也是(shi)(shi)為了安(an)全。

2、鋰離子/聚(ju)合物電(dian)池充電(dian)方案

鋰離子/聚合物(wu)電(dian)池(chi)的(de)充(chong)電(dian)方案對于不同(tong)數量的(de)電(dian)芯、電(dian)芯配置以及電(dian)源類(lei)型還是(shi)不同(tong)的(de)。目前主(zhu)要(yao)有3種主(zhu)要(yao)的(de)充(chong)電(dian)方案：線性，Buck(降壓)開關和SEPIC(升壓與降壓)開關。

2.1線性方案

當充(chong)電(dian)(dian)器輸(shu)入(ru)電(dian)(dian)壓大于全充(chong)滿(man)電(dian)(dian)芯(xin)加上充(chong)足凈空之后(hou)的(de)(de)開(kai)(kai)路(lu)電(dian)(dian)壓時(shi)，最(zui)好用線(xian)(xian)性方(fang)案(an)(an)，特(te)別(bie)是(shi)1.0C快速充(chong)電(dian)(dian)電(dian)(dian)流不比1A大太多時(shi)。比如，MP3播放器通常(chang)只有(you)一個電(dian)(dian)芯(xin)，容量從700到1500mAh不等(deng)，滿(man)充(chong)開(kai)(kai)路(lu)電(dian)(dian)壓是(shi)4.2V。MP3播放機(ji)的(de)(de)電(dian)(dian)源通常(chang)是(shi)AC／DC適配器或者是(shi)USB接口(kou)，其輸(shu)出(chu)是(shi)規則的(de)(de)5V；這時(shi)，線(xian)(xian)性方(fang)案(an)(an)的(de)(de)充(chong)電(dian)(dian)器就是(shi)最(zui)簡單、最(zui)有(you)效率(lv)的(de)(de)方(fang)案(an)(an)。圖2所示為鋰(li)離(li)子/聚合物(wu)電(dian)(dian)池充(chong)電(dian)(dian)方(fang)案(an)(an)線(xian)(xian)性方(fang)案(an)(an),基(ji)本結構和線(xian)(xian)性電(dian)(dian)壓規整器一樣。

*線(xian)性方案的充(chong)電器(qi)應用例舉(ju)-雙(shuang)輸入Li+充(chong)電器(qi)及(ji)智(zhi)能(neng)電源(yuan)選擇器(qi)MAX8677A。MAX8677A是(shi)雙(shuang)輸入USB/AC適配器(qi)線(xian)性充(chong)電器(qi)，內置Smart Power Selector，用于由可充(chong)電單節Li+電池供電的便攜式設備。該(gai)充(chong)電器(qi)集成了(le)電池和外部電源(yuan)充(chong)電和切(qie)換負載所(suo)需的全部功(gong)率開關，因此無(wu)需外部 MOSFET。MAX8677A理想用于便攜式設備，例如智(zhi)能(neng)手機(ji)、PDA、便攜式多媒體(ti)播放器(qi)、GPS導航設備、數碼相機(ji)、以(yi)及(ji)數碼攝(she)像機(ji)。

MAX8677A可以工作于獨立的USB和AC適配器電源輸入下或兩個輸入中的任意一個輸入下。當連接外部電源時，智能電源選擇器允許系統不連接電池或可以與深度放電電池連接。智能充電器電(dian)(dian)(dian)(dian)源(yuan)(yuan)選(xuan)擇器(qi)自(zi)動將電(dian)(dian)(dian)(dian)池切(qie)換到系(xi)統負載，使(shi)用系(xi)統未(wei)利用的(de)輸(shu)入(ru)電(dian)(dian)(dian)(dian)源(yuan)(yuan)部分(fen)(fen)為(wei)電(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)，充(chong)分(fen)(fen)利用有限的(de)USB和(he)適(shi)配器(qi)輸(shu)入(ru)電(dian)(dian)(dian)(dian)源(yuan)(yuan)。所有需要的(de)電(dian)(dian)(dian)(dian)流檢測電(dian)(dian)(dian)(dian)路，包括集成的(de)功率開關，均集成于片(pian)上。DC輸(shu)入(ru)電(dian)(dian)(dian)(dian)流限最高可調節(jie)至2A，而(er)DC和(he)USB輸(shu)入(ru)均可支持100mA、500mA、和(he)USB掛起模式。充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流可調節(jie)至高達1.5A，從(cong)而(er)支持 寬(kuan)范(fan)圍(wei)的(de)電(dian)(dian)(dian)(dian)池容性。MAX8677A的(de)其他特性包括熱(re)(re)調節(jie)、過(guo)壓(ya)保護、充(chong)電(dian)(dian)(dian)(dian)狀態和(he)故障輸(shu)出、電(dian)(dian)(dian)(dian)源(yuan)(yuan)好監視、電(dian)(dian)(dian)(dian)池熱(re)(re)敏電(dian)(dian)(dian)(dian)阻監視、以(yi)及充(chong)電(dian)(dian)(dian)(dian)定時器(qi)。MAX8677A采用節(jie)省空間(jian)的(de)、熱(re)(re)增強型(xing)、4mm×4mm、24引腳的(de)TQFN封裝，規定工作于擴展級溫度范(fan)圍(wei)(-40～+85℃)。

2.2 Buck(降壓)開關(guan)方案

當(dang)1.0C充(chong)電(dian)(dian)(dian)(dian)的(de)(de)(de)電(dian)(dian)(dian)(dian)流大(da)于1A，或者輸入(ru)(ru)電(dian)(dian)(dian)(dian)壓(ya)(ya)比電(dian)(dian)(dian)(dian)芯(xin)的(de)(de)(de)全(quan)(quan)充(chong)滿開路電(dian)(dian)(dian)(dian)壓(ya)(ya)高(gao)很多時，Buck或者降(jiang)壓(ya)(ya)方(fang)(fang)案(an)就是(shi)一個更好的(de)(de)(de)選擇。比如，在基于硬盤的(de)(de)(de)PMP中，通常使用單(dan)芯(xin)鋰(li)離子電(dian)(dian)(dian)(dian)池，全(quan)(quan)充(chong)滿開路電(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)4.2V，容量(liang)從1200到(dao)2400mAh不等(deng)。而(er)現在PMP通常是(shi)用汽(qi)車(che)套件(jian)來充(chong)電(dian)(dian)(dian)(dian)，它(ta)的(de)(de)(de)輸出電(dian)(dian)(dian)(dian)壓(ya)(ya)在9V到(dao)16V之(zhi)(zhi)間。在輸入(ru)(ru)電(dian)(dian)(dian)(dian)壓(ya)(ya)和電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)之(zhi)(zhi)間比較(jiao)高(gao)的(de)(de)(de)電(dian)(dian)(dian)(dian)壓(ya)(ya)差(最(zui)小4.8V)會讓線性(xing)方(fang)(fang)案(an)降(jiang)低(di)(di)效率。這(zhe)種低(di)(di)效率，加上大(da)于1.2A的(de)(de)(de)1C快速充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，會產(chan)生嚴重的(de)(de)(de)散熱(re)問題。為避免這(zhe)種情(qing)況(kuang)，就要采(cai)用Buck方(fang)(fang)案(an)。圖(tu)3為鋰(li)電(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)器方(fang)(fang)案(an)示意圖(tu),基本結(jie)構同(tong)Buck(降(jiang)壓(ya)(ya))開關(guan)電(dian)(dian)(dian)(dian)壓(ya)(ya)調節器完全(quan)(quan)相同(tong)。

2.3 SEPIC(升壓與降(jiang)壓)開關方(fang)案

在(zai)(zai)(zai)某些使用(yong)(yong)(yong)3個甚(shen)至4個鋰(li)離子(zi)／聚合物電(dian)芯(xin)串聯(lian)的(de)設(she)備(bei)中，充電(dian)器的(de)輸(shu)入電(dian)壓(ya)(ya)(ya)就(jiu)不總是(shi)大(da)于電(dian)池(chi)電(dian)壓(ya)(ya)(ya)。比(bi)如，筆記本電(dian)腦使用(yong)(yong)(yong)3芯(xin)鋰(li)離子(zi)電(dian)池(chi)組(zu)，滿充開路電(dian)壓(ya)(ya)(ya)是(shi)12．6V(4．2V x3)，容量從1800mAh到3600mAh。輸(shu)入電(dian)源要么是(shi)輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)1 6V的(de)AC／DC適(shi)配器，要么是(shi)汽車套件(jian)，輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)在(zai)(zai)(zai)9V到16V之(zhi)間。很顯然地，線性(xing)和(he)Buck方案都(dou)不能為這組(zu)電(dian)池(chi)組(zu)充電(dian)。這就(jiu)要用(yong)(yong)(yong)上SEPIC方案，它能在(zai)(zai)(zai)輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)高于電(dian)池(chi)電(dian)壓(ya)(ya)(ya)時工作(zuo)，也能在(zai)(zai)(zai)輸(shu)出(chu)電(dian)壓(ya)(ya)(ya)低于電(dian)池(chi)時工作(zuo)。

3、電量檢測算法

許多可攜(xie)式產品(pin)都利用電(dian)壓測量(liang)(liang)(liang)值來估計(ji)電(dian)池(chi)剩馀電(dian)量(liang)(liang)(liang)，但是(shi)電(dian)池(chi)電(dian)壓與剩馀電(dian)量(liang)(liang)(liang)的(de)(de)關系卻會(hui)隨著放電(dian)率(lv)、溫度(du)和電(dian)池(chi)老(lao)化程度(du)而(er)改變，使(shi)這種方法的(de)(de)誤(wu)差(cha)率(lv)最高可達(da)50％。市場對使(shi)用時間更(geng)長的(de)(de)產品(pin)需求(qiu)不斷(duan)增(zeng)強，因此(ci)系統設計(ji)人(ren)員需要更(geng)加精(jing)確(que)的(de)(de)解決方案。使(shi)用電(dian)量(liang)(liang)(liang)檢測計(ji)吧來測量(liang)(liang)(liang)電(dian)池(chi)充人(ren)或消耗的(de)(de)電(dian)量(liang)(liang)(liang)，將能(neng)夠在很寬(kuan)的(de)(de)應用電(dian)源級(ji)別范(fan)圍內提(ti)供更(geng)精(jing)確(que)的(de)(de)電(dian)池(chi)電(dian)量(liang)(liang)(liang)估測。

3.1電(dian)量檢測算法(fa)應用舉例之(zhi)一(yi),功能完(wan)整的(de)單＼雙電(dian)池(chi)便攜式應用電(dian)池(chi)組設(she)計

*電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)原理(li)(li)(li).較好的(de)(de)電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計至少要(yao)具備電(dian)(dian)池(chi)電(dian)(dian)壓、電(dian)(dian)池(chi)組溫度(du)和電(dian)(dian)流、測(ce)(ce)(ce)(ce)(ce)量(liang)方法；一個(ge)(ge)(ge)(ge)微(wei)處(chu)理(li)(li)(li)9a；和一套及(ji)業經(jing)驗證的(de)(de)電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)算(suan)法。bq2650x及(ji)bq27x00是功(gong)能完整(zheng)的(de)(de)電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計，具有一個(ge)(ge)(ge)(ge)測(ce)(ce)(ce)(ce)(ce)量(liang)電(dian)(dian)壓與(yu)(yu)溫度(du)的(de)(de)模數(shu)轉換(huan)器(qi)(qi)(ADC)和一個(ge)(ge)(ge)(ge)測(ce)(ce)(ce)(ce)(ce)量(liang)電(dian)(dian)流與(yu)(yu)充電(dian)(dian)感(gan)測(ce)(ce)(ce)(ce)(ce)的(de)(de)模數(shu)轉換(huan)器(qi)(qi)。這(zhe)些(xie)(xie)(xie)電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計還具有一個(ge)(ge)(ge)(ge)微(wei)處(chu)理(li)(li)(li)器(qi)(qi)，負責執行(xing)德州(zhou)儀器(qi)(qi)的(de)(de)電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)算(suan)法。這(zhe)些(xie)(xie)(xie)演(yan)算(suan)法會補(bu)償(chang)鋰離(li)子電(dian)(dian)池(chi)的(de)(de)自放電(dian)(dian)、老化(hua)、溫度(du)和放電(dian)(dian)率等因素。晶(jing)片內含微(wei)處(chu)理(li)(li)(li)器(qi)(qi)為主機(ji)系統處(chu)理(li)(li)(li)器(qi)(qi)省下這(zhe)些(xie)(xie)(xie)計算(suan)負擔(dan).電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計能夠提(ti)供剩余電(dian)(dian)量(liang)狀態等信息(xi)(xi)，bq27x00系列產品(pin)還提(ti)供剩余可(ke)運行(xing)時間(Run Time to Empty)主機(ji)可(ke)隨時向電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計查(cha)詢這(zhe)些(xie)(xie)(xie)信息(xi)(xi)，再透過LED指示(shi)燈或屏幕(mu)顯示(shi)將電(dian)(dian)池(chi)信息(xi)(xi)通(tong)知(zhi)用(yong)戶。電(dian)(dian)量(liang)檢測(ce)(ce)(ce)(ce)(ce)計的(de)(de)使用(yong)非常方便，系統處(chu)理(li)(li)(li)器(qi)(qi)僅需要(yao)配(pei)置(zhi)12C或HDQ通(tong)信驅(qu)動(dong)器(qi)(qi)即可(ke)。

*電(dian)(dian)(dian)(dian)(dian)(dian)池組電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)描述.圖4(a)為可(ke)(ke)選用(yong)(yong)具有(you)鑒(jian)定功能IC的(de)典型(xing)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)池組應(ying)用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。根據所使用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)量檢(jian)測(ce)計(ji)IC的(de)不同，電(dian)(dian)(dian)(dian)(dian)(dian)池組至少需要有(you)三到(dao)四個外(wai)部(bu)終端(duan)(duan)。VCC及(ji)(ji)BAT引腳會連(lian)到(dao)電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，以便為，C供電(dian)(dian)(dian)(dian)(dian)(dian)及(ji)(ji)測(ce)量電(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。電(dian)(dian)(dian)(dian)(dian)(dian)池接地(di)端(duan)(duan)連(lian)接了一個電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值較(jiao)小的(de)檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)，讓電(dian)(dian)(dian)(dian)(dian)(dian)量檢(jian)測(ce)計(ji)的(de)高阻(zu)抗SRP及(ji)(ji)SRN輸(shu)入(ru)端(duan)(duan)能夠監控感測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)兩(liang)端(duan)(duan)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。通(tong)過(guo)流經檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)流可(ke)(ke)用(yong)(yong)來判(pan)斷電(dian)(dian)(dian)(dian)(dian)(dian)池充入(ru)或(huo)釋(shi)放的(de)電(dian)(dian)(dian)(dian)(dian)(dian)量。設(she)計(ji)人員(yuan)選擇檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值時必須(xu)(xu)考慮電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)兩(liang)端(duan)(duan)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不能超過(guo)100 mV，過(guo)低(di)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值可(ke)(ke)能會在電(dian)(dian)(dian)(dian)(dian)(dian)流較(jiao)小時產生誤差。電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)板(ban)布局(ju)必須(xu)(xu)確保從SRP及(ji)(ji)SRN到(dao)檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)(qi)的(de)連(lian)接要盡可(ke)(ke)能靠近感測(ce)電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)端(duan)(duan)；換言之(zhi)，它們應(ying)該是采用(yong)(yong)Kelvin連(lian)線(xian)。

HDQ引腳需(xu)要外部上(shang)拉(la)電(dian)阻(zu)器(qi)，該電(dian)阻(zu)應(ying)位于主機或主應(ying)用端(duan)，這(zhe)樣電(dian)量檢測計才能在電(dian)池組與便攜式設備連(lian)接斷(duan)開時啟用睡眠功(gong)能。建(jian)議上(shang)拉(la)電(dian)阻(zu)值選用10 kΩ。

*電(dian)池(chi)(chi)(chi)組(zu)(zu)鑒定(ding)(ding)。價格低廉的偽冒(mao)電(dian)池(chi)(chi)(chi)的問(wen)題(ti)日(ri)益嚴(yan)重，這(zhe)些電(dian)池(chi)(chi)(chi)可能不包(bao)(bao)含(han)OEM廠(chang)商要求(qiu)的安全(quan)保護電(dian)路。所(suo)以，真(zhen)品電(dian)池(chi)(chi)(chi)組(zu)(zu)可包(bao)(bao)含(han)圖4(a)所(suo)示的鑒定(ding)(ding)電(dian)路。當要鑒定(ding)(ding)電(dian)池(chi)(chi)(chi)時，主(zhu)機(ji)向含(han)有IC(bq26150，作(zuo)用是(shi)(shi)循環冗余(yu)校(xiao)驗(CRC))的電(dian)池(chi)(chi)(chi)組(zu)(zu)發出(chu)(chu)一(yi)個詢(xun)(xun)問(wen)值(challenge)，電(dian)池(chi)(chi)(chi)組(zu)(zu)所(suo)含(han)的CRC會根(gen)據這(zhe)個詢(xun)(xun)問(wen)值和，IC中內建的CRC多項式計(ji)算這(zhe)個CRC值。CRC是(shi)(shi)基于主(zhu)機(ji)的查詢(xun)(xun)命令與IC中秘(mi)密定(ding)(ding)義的CRC多項式完成的，主(zhu)機(ji)也會進行(xing)CRC值計(ji)算井與電(dian)池(chi)(chi)(chi)組(zu)(zu)的計(ji)算結果比(bi)較(jiao)以確定(ding)(ding)鑒定(ding)(ding)是(shi)(shi)否(fou)成功。一(yi)旦電(dian)池(chi)(chi)(chi)通(tong)(tong)過鑒定(ding)(ding)，bq26150則會發出(chu)(chu)指(zhi)令以確保主(zhu)機(ji)與電(dian)量(liang)檢測計(ji)之間(jian)的資料線(xian)路通(tong)(tong)訊正(zheng)常。當電(dian)池(chi)(chi)(chi)連(lian)(lian)接(jie)(jie)中斷或重新連(lian)(lian)接(jie)(jie)時，整個鑒定(ding)(ding)過程將重復(fu)一(yi)次。

3.2電量檢測算法(fa)應(ying)用舉例之(zhi)二(er),能適用于各種通用電量計的新(xin)型IC.

當今不少制造廠商可(ke)提供種類豐富的電量計(ji)IC,，用戶可(ke)從中(zhong)選取合適的功能器件(jian)，以優化產品的性價比(bi)。利用電量計(ji)貯(zhu)測量的電池(chi)(chi)參數，這種分離式架構允許(xu)用戶在(zai)主機內定制電量計(ji)量算法(fa)．從而(er)省去電池(chi)(chi)組內嵌處理器的成本。值(zhi)此以Dallase semicconductor公司(si)名為例(li)的DS2762芯片作典型分析. 一新型分離式電量計(ji)IC,其結構見圖5(a)所示.

*DS2762應用特征

DS2762是一款單節鋰電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)量計與保護(hu)電(dian)(dian)(dian)(dian)(dian)路，集(ji)成于一片(pian)微(wei)小的(de)(de)(de)2.46mm× 2.74mm倒裝(zhuang)片(pian)封(feng)裝(zhuang)。由于內部集(ji)成了用于電(dian)(dian)(dian)(dian)(dian)量檢測的(de)(de)(de)高精密電(dian)(dian)(dian)(dian)(dian)阻，該(gai)款器(qi)件非常(chang)(chang)節省空間。它(ta)所具有的(de)(de)(de)小尺寸和無(wu)可比擬的(de)(de)(de)高集(ji)成度，對(dui)于移動電(dian)(dian)(dian)(dian)(dian)話電(dian)(dian)(dian)(dian)(dian)池(chi)組及其它(ta)類(lei)似的(de)(de)(de)手持產品，如PDA等，都非常(chang)(chang)理想。集(ji)成的(de)(de)(de)保護(hu)電(dian)(dian)(dian)(dian)(dian)路連續地監視(shi)(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)過(guo)壓(ya)、欠壓(ya)和過(guo)流故障(充(chong)電(dian)(dian)(dian)(dian)(dian)或放(fang)電(dian)(dian)(dian)(dian)(dian)期間)。不(bu)同于獨立的(de)(de)(de)保護(hu)IC，DS2762允(yun)許主處理器(qi)監視(shi)(shi)/控制保護(hu)FET的(de)(de)(de)導通狀態，這(zhe)樣，可以通過(guo)DS2762的(de)(de)(de)保護(hu)電(dian)(dian)(dian)(dian)(dian)路實現系統電(dian)(dian)(dian)(dian)(dian)源控制。DS2762也可以充(chong)電(dian)(dian)(dian)(dian)(dian)一個已深(shen)度消耗的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池(chi)，當電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)不(bu)足3V時，提供一條限制電(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)恢復充(chong)電(dian)(dian)(dian)(dian)(dian)路徑。

DS2762能夠精確監視電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)壓(ya)和溫(wen)度(du)，其(qi)動(dong)態范圍(wei)與(yu)分辨(bian)率滿足(zu)任何通行的(de)(de)(de)移動(dong)通信(xin)產(chan)品的(de)(de)(de)測(ce)(ce)試標準。測(ce)(ce)得的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流對內部產(chan)生的(de)(de)(de)時基進行積分，實現電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang)。通過實時、連續的(de)(de)(de)自動(dong)失調(diao)糾正，電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang)的(de)(de)(de)精度(du)得以提(ti)高。內置的(de)(de)(de)檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)消(xiao)除了(le)因(yin)制造(zao)工藝和溫(wen)度(du)而造(zao)成(cheng)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)變化，進一(yi)步(bu)提(ti)高了(le)電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)計的(de)(de)(de)精度(du)。重要(yao)數(shu)據(ju)(ju)保存(cun)于(yu)32字節(jie)(jie)(jie)、可加鎖(suo)的(de)(de)(de)EEPROM；16字節(jie)(jie)(jie)的(de)(de)(de)SRAM用于(yu)保存(cun)動(dong)態數(shu)據(ju)(ju)。與(yu)DS2762的(de)(de)(de)所有通信(xin)均通過1-Wire、多節(jie)(jie)(jie)點通信(xin)接口進行，最大限度(du)減少了(le)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組與(yu)主(zhu)機(ji)的(de)(de)(de)連線。其(qi)主(zhu)要(yao)特征為；單節(jie)(jie)(jie)鋰(li)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)保護器；高精度(du)電(dian)(dian)(dian)(dian)(dian)流(電(dian)(dian)(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang))、電(dian)(dian)(dian)(dian)(dian)壓(ya)和溫(wen)度(du)測(ce)(ce)量(liang)(liang)；可選的(de)(de)(de)集成(cheng)25mΩ檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)(zu)，每個DS2762經過單獨微調(diao)；0V電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)恢復充電(dian)(dian)(dian)(dian)(dian)；32字節(jie)(jie)(jie)可加鎖(suo)EEPROM，16字節(jie)(jie)(jie)SRAM，64位(wei)ROM；

1-Wire，多(duo)節(jie)點(dian)，數(shu)字通信(xin)接口；支持多(duo)電池組電源(yuan)管理(li)，并通過保護(hu)FET實現系統電源(yuan)控制；休(xiu)眠模(mo)式下(xia)(xia)電源(yuan)電流(liu)僅(jin)2?A(最大);工作模(mo)式下(xia)(xia)電源(yuan)電流(liu)為90?A(最大);2.46mm×2.74mm倒裝片封裝或16引腳下(xia)(xia)SSOP封裝，兩者均可選(xuan)擇帶(dai)或不帶(dai)檢測電阻;復具有備有評(ping)估板(ban).

4、結論

應用好便攜式電(dian)(dian)子設備的電(dian)(dian)池技術是選(xuan)擇鋰離子電(dian)(dian)池和鋰聚合物電(dian)(dian)池及其充電(dian)(dian)器(qi)的基礎.之(zhi)于如何正確選(xuan)擇,還(huan)必須視(shi)便攜式電(dian)(dian)子備的具(ju)體要求而定。