如今的(de)便(bian)攜(xie)式電(dian)(dian)(dian)子(zi)備(bei)中(zhong)電(dian)(dian)(dian)池(chi)(chi)技(ji)術包(bao)括電(dian)(dian)(dian)量檢測算法、電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)算法與(yu)電(dian)(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)(dian)技(ji)術等(deng)幾個方面。眾(zhong)所周知(zhi)(zhi),充(chong)電(dian)(dian)(dian)式電(dian)(dian)(dian)池(chi)(chi)化(hua)學(xue)反應(ying)有鎳(nie)(nie)鎘、鎳(nie)(nie)氫、鋰離子(zi)和鋰聚(ju)合物(wu)4種程(cheng)式,作(zuo)為便(bian)攜(xie)式電(dian)(dian)(dian)子(zi)設備(bei)來說,雖(sui)然這4種電(dian)(dian)(dian)池(chi)(chi)程(cheng)式各有特(te)點,但從(cong)能量密度與(yu)安全(quan)性(xing)角度的(de)發(fa)展(zhan)與(yu)實(shi)踐(jian)可(ke)知(zhi)(zhi), 鋰離子(zi)電(dian)(dian)(dian)池(chi)(chi)和鋰聚(ju)合物(wu)電(dian)(dian)(dian)池(chi)(chi)的(de)優勢(shi)己成(cheng)為小型(xing)長(chang)運行(xing)時間(jian)的(de)設備(bei)的(de)理想之選(xuan)，比如筆記本電(dian)(dian)(dian)腦以及基于硬盤(pan)的(de)PMP等(deng).對便(bian)攜(xie)式電(dian)(dian)(dian)子(zi)備(bei)工(gong)程(cheng)師來說，正(zheng)確選(xuan)擇(ze)與(yu)應(ying)用好便(bian)攜(xie)式電(dian)(dian)(dian)子(zi)備(bei)中(zhong)電(dian)(dian)(dian)池(chi)(chi)技(ji)術至(zhi)關重要,值此本文將(jiang)對此作(zuo)研討(tao),并作(zuo)應(ying)用舉例分析.

1、關于細流充(chong)電(dian)、快速充(chong)電(dian)和穩定充(chong)電(dian)的電(dian)池(chi)充(chong)電(dian)算法

根據最(zui)終(zhong)應(ying)用的(de)(de)能量需(xu)求(qiu)，一個(ge)電(dian)(dian)(dian)(dian)池組(zu)(zu)可能包含最(zui)多4個(ge)鋰(li)離子或鋰(li)聚(ju)合物(wu)電(dian)(dian)(dian)(dian)池芯(xin)(xin),其配置可有多種變化(hua)，同時帶有一個(ge)主流的(de)(de)電(dian)(dian)(dian)(dian)源(yuan)適(shi)配器：直接的(de)(de)適(shi)配器、USB接口或汽車充(chong)(chong)電(dian)(dian)(dian)(dian)器。除(chu)去(qu)電(dian)(dian)(dian)(dian)芯(xin)(xin)數量、電(dian)(dian)(dian)(dian)芯(xin)(xin)的(de)(de)配置或電(dian)(dian)(dian)(dian)源(yuan)適(shi)配器類型上的(de)(de)差別，這些電(dian)(dian)(dian)(dian)池組(zu)(zu)都有同樣的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)特性。因此它們的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)算(suan)法也(ye)一樣。鋰(li)離子與鋰(li)聚(ju)合物(wu)電(dian)(dian)(dian)(dian)池最(zui)好的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)算(suan)法可以分(fen)為3個(ge)階段：細流充(chong)(chong)電(dian)(dian)(dian)(dian)、快速充(chong)(chong)電(dian)(dian)(dian)(dian)和穩定充(chong)(chong)電(dian)(dian)(dian)(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(wen)定(ding)(ding)電(dian)(dian)壓。在快速充(chong)電(dian)(dian)過(guo)程中(zhong)，一旦電(dian)(dian)芯(xin)電(dian)(dian)壓達到4.2V，穩(wen)定(ding)(ding)電(dian)(dian)壓階段(duan)就開始(shi)了(le)。這時(shi)(shi)(shi)可通過(guo)最(zui)小(xiao)充(chong)電(dian)(dian)電(dian)(dian)流或定(ding)(ding)時(shi)(shi)(shi)器(qi)或這兩者(zhe)的聯合(he)來中(zhong)斷充(chong)電(dian)(dian).當最(zui)小(xiao)電(dian)(dian)流低于(yu)大約(yue)0.07C時(shi)(shi)(shi)，可中(zhong)斷充(chong)電(dian)(dian)。定(ding)(ding)時(shi)(shi)(shi)器(qi)則要靠一個預設的定(ding)(ding)時(shi)(shi)(shi)器(qi)來觸發中(zhong)斷。

高級的電池充電器通常(chang)帶(dai)有附加(jia)的安(an)全功能。比如(ru)，如(ru)果(guo)(guo)電(dian)(dian)芯溫度(du)超出給定窗(chuang)口，通常(chang)是(shi)0℃--45℃，充(chong)電(dian)(dian)就(jiu)會暫停。除去某些非常(chang)低(di)端的設備，現在市(shi)面上的鋰離子／鋰聚合物電(dian)(dian)池充(chong)電(dian)(dian)方案都集成或是(shi)帶(dai)有外(wai)置的元件(jian)，以便按照充(chong)電(dian)(dian)特性進行充(chong)電(dian)(dian)，這不光(guang)是(shi)為(wei)了(le)取(qu)得更佳充(chong)電(dian)(dian)效果(guo)(guo)，同時(shi)也(ye)是(shi)為(wei)了(le)安(an)全。

2、鋰離子/聚合物電(dian)(dian)池充電(dian)(dian)方案

鋰(li)離子(zi)/聚(ju)合(he)物電(dian)(dian)池(chi)的(de)充(chong)電(dian)(dian)方(fang)案(an)對于不同數量的(de)電(dian)(dian)芯(xin)(xin)、電(dian)(dian)芯(xin)(xin)配置以及電(dian)(dian)源類(lei)型還(huan)是不同的(de)。目前(qian)主要有3種主要的(de)充(chong)電(dian)(dian)方(fang)案(an)：線性，Buck(降壓(ya))開關和SEPIC(升(sheng)壓(ya)與降壓(ya))開關。

2.1線性方案

當充(chong)(chong)(chong)電(dian)(dian)器(qi)輸入電(dian)(dian)壓大于全充(chong)(chong)(chong)滿(man)電(dian)(dian)芯加上充(chong)(chong)(chong)足凈空(kong)之后的(de)(de)開(kai)路電(dian)(dian)壓時，最好(hao)用線(xian)性方案(an)，特別(bie)是1.0C快(kuai)速充(chong)(chong)(chong)電(dian)(dian)電(dian)(dian)流(liu)不比1A大太多時。比如，MP3播(bo)放(fang)器(qi)通常只有一個電(dian)(dian)芯，容(rong)量(liang)從700到1500mAh不等，滿(man)充(chong)(chong)(chong)開(kai)路電(dian)(dian)壓是4.2V。MP3播(bo)放(fang)機的(de)(de)電(dian)(dian)源通常是AC／DC適(shi)配器(qi)或(huo)者是USB接口(kou)，其輸出是規則的(de)(de)5V；這時，線(xian)性方案(an)的(de)(de)充(chong)(chong)(chong)電(dian)(dian)器(qi)就是最簡(jian)單(dan)、最有效率的(de)(de)方案(an)。圖2所示(shi)為鋰離子/聚合物電(dian)(dian)池充(chong)(chong)(chong)電(dian)(dian)方案(an)線(xian)性方案(an),基本結(jie)構和線(xian)性電(dian)(dian)壓規整器(qi)一樣。

*線(xian)性方案的(de)充(chong)電(dian)器(qi)(qi)應用例舉-雙輸入Li+充(chong)電(dian)器(qi)(qi)及智能電(dian)源選擇器(qi)(qi)MAX8677A。MAX8677A是(shi)雙輸入USB/AC適配(pei)器(qi)(qi)線(xian)性充(chong)電(dian)器(qi)(qi)，內置(zhi)Smart Power Selector，用于由可充(chong)電(dian)單節Li+電(dian)池(chi)供電(dian)的(de)便(bian)攜(xie)式設(she)備。該充(chong)電(dian)器(qi)(qi)集成了(le)電(dian)池(chi)和外部電(dian)源充(chong)電(dian)和切(qie)換負載(zai)所需的(de)全(quan)部功率開關，因此無需外部 MOSFET。MAX8677A理想用于便(bian)攜(xie)式設(she)備，例如智能手機(ji)(ji)(ji)、PDA、便(bian)攜(xie)式多媒體(ti)播放器(qi)(qi)、GPS導航設(she)備、數(shu)碼(ma)相機(ji)(ji)(ji)、以及數(shu)碼(ma)攝像機(ji)(ji)(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)(dian)(dian)(dian)源(yuan)選擇器自(zi)動將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)切(qie)換到系(xi)統(tong)負(fu)載，使用系(xi)統(tong)未利(li)用的(de)(de)輸(shu)(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)部分(fen)為電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)，充(chong)(chong)(chong)分(fen)利(li)用有(you)限(xian)(xian)的(de)(de)USB和適配器輸(shu)(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)。所(suo)有(you)需要的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流檢測電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路，包(bao)括集成的(de)(de)功(gong)率開關(guan)，均集成于片上。DC輸(shu)(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流限(xian)(xian)最高可(ke)調(diao)節至(zhi)2A，而DC和USB輸(shu)(shu)(shu)入(ru)均可(ke)支(zhi)持100mA、500mA、和USB掛起模式。充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流可(ke)調(diao)節至(zhi)高達(da)1.5A，從而支(zhi)持 寬范圍的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)容性。MAX8677A的(de)(de)其他特(te)性包(bao)括熱調(diao)節、過壓保護、充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)狀態和故障輸(shu)(shu)(shu)出、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)好監視、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)熱敏電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻監視、以及充(chong)(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)定(ding)(ding)時器。MAX8677A采用節省(sheng)空間的(de)(de)、熱增強型、4mm×4mm、24引腳的(de)(de)TQFN封裝，規(gui)定(ding)(ding)工作于擴(kuo)展級(ji)溫度范圍(-40～+85℃)。

2.2 Buck(降(jiang)壓)開關方案

當1.0C充(chong)電(dian)(dian)的(de)電(dian)(dian)流大(da)于(yu)(yu)1A，或者輸(shu)入電(dian)(dian)壓(ya)(ya)(ya)比(bi)電(dian)(dian)芯的(de)全充(chong)滿開(kai)路電(dian)(dian)壓(ya)(ya)(ya)高(gao)很多時，Buck或者降壓(ya)(ya)(ya)方案就(jiu)是一個更好(hao)的(de)選擇。比(bi)如，在(zai)基于(yu)(yu)硬盤(pan)的(de)PMP中，通常(chang)使用單芯鋰離子電(dian)(dian)池(chi)，全充(chong)滿開(kai)路電(dian)(dian)壓(ya)(ya)(ya)是4.2V，容量從1200到2400mAh不等。而現在(zai)PMP通常(chang)是用汽車套件來充(chong)電(dian)(dian)，它的(de)輸(shu)出電(dian)(dian)壓(ya)(ya)(ya)在(zai)9V到16V之間。在(zai)輸(shu)入電(dian)(dian)壓(ya)(ya)(ya)和(he)電(dian)(dian)池(chi)電(dian)(dian)壓(ya)(ya)(ya)之間比(bi)較高(gao)的(de)電(dian)(dian)壓(ya)(ya)(ya)差(最小4.8V)會(hui)讓線性(xing)方案降低效(xiao)率。這種(zhong)低效(xiao)率，加上(shang)大(da)于(yu)(yu)1.2A的(de)1C快速(su)充(chong)電(dian)(dian)電(dian)(dian)流，會(hui)產生嚴重的(de)散熱問題。為(wei)避免這種(zhong)情況，就(jiu)要(yao)采用Buck方案。圖(tu)3為(wei)鋰電(dian)(dian)池(chi)充(chong)電(dian)(dian)器(qi)方案示意圖(tu),基本結構同Buck(降壓(ya)(ya)(ya))開(kai)關(guan)電(dian)(dian)壓(ya)(ya)(ya)調節器(qi)完全相同。

2.3 SEPIC(升壓與降壓)開關方案

在某些使用3個甚至(zhi)4個鋰離子／聚合物電(dian)(dian)(dian)(dian)(dian)(dian)芯串(chuan)聯的設(she)備(bei)中，充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器(qi)的輸(shu)(shu)入電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)就不總是(shi)大(da)于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。比如，筆記本電(dian)(dian)(dian)(dian)(dian)(dian)腦使用3芯鋰離子電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組，滿充(chong)開路電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)12．6V(4．2V x3)，容量從1800mAh到(dao)3600mAh。輸(shu)(shu)入電(dian)(dian)(dian)(dian)(dian)(dian)源要(yao)么是(shi)輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)1 6V的AC／DC適配器(qi)，要(yao)么是(shi)汽車(che)套件(jian)，輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)在9V到(dao)16V之(zhi)間。很(hen)顯然地(di)，線(xian)性(xing)和Buck方案(an)都不能為這組電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。這就要(yao)用上(shang)SEPIC方案(an)，它能在輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)高于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)時工作，也能在輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)低于(yu)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)時工作。

3、電量檢測算法

許多可攜式產(chan)品(pin)都(dou)利用(yong)電(dian)(dian)(dian)壓測(ce)量值來(lai)估計電(dian)(dian)(dian)池(chi)剩馀電(dian)(dian)(dian)量，但是(shi)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓與剩馀電(dian)(dian)(dian)量的(de)(de)(de)關系卻會隨著(zhu)放電(dian)(dian)(dian)率、溫度和電(dian)(dian)(dian)池(chi)老化(hua)程度而改變，使這種方法的(de)(de)(de)誤差率最高(gao)可達50％。市場對使用(yong)時間(jian)更長的(de)(de)(de)產(chan)品(pin)需求不斷增強，因此系統(tong)設計人員需要更加精(jing)確(que)的(de)(de)(de)解決方案。使用(yong)電(dian)(dian)(dian)量檢測(ce)計吧(ba)來(lai)測(ce)量電(dian)(dian)(dian)池(chi)充人或消耗的(de)(de)(de)電(dian)(dian)(dian)量，將能夠在很寬的(de)(de)(de)應用(yong)電(dian)(dian)(dian)源級(ji)別范圍內(nei)提供更精(jing)確(que)的(de)(de)(de)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)量估測(ce)。

3.1電量(liang)檢(jian)測(ce)算(suan)法應用舉例之一(yi),功能完整的單＼雙電池便攜式應用電池組設計

*電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)原理.較(jiao)好的(de)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)至少要具(ju)備電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓、電(dian)(dian)(dian)池(chi)組溫度和電(dian)(dian)(dian)流(liu)、測(ce)量(liang)(liang)(liang)(liang)(liang)方法(fa)；一(yi)個微處(chu)理9a；和一(yi)套及業經(jing)驗證(zheng)的(de)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)算法(fa)。bq2650x及bq27x00是功能完整的(de)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)，具(ju)有一(yi)個測(ce)量(liang)(liang)(liang)(liang)(liang)電(dian)(dian)(dian)壓與溫度的(de)模數轉換器(qi)(qi)(ADC)和一(yi)個測(ce)量(liang)(liang)(liang)(liang)(liang)電(dian)(dian)(dian)流(liu)與充電(dian)(dian)(dian)感測(ce)的(de)模數轉換器(qi)(qi)。這(zhe)(zhe)(zhe)些(xie)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)還(huan)具(ju)有一(yi)個微處(chu)理器(qi)(qi)，負(fu)責執行(xing)德州儀器(qi)(qi)的(de)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)算法(fa)。這(zhe)(zhe)(zhe)些(xie)演算法(fa)會(hui)補償鋰離(li)子電(dian)(dian)(dian)池(chi)的(de)自(zi)放(fang)電(dian)(dian)(dian)、老(lao)化(hua)、溫度和放(fang)電(dian)(dian)(dian)率等(deng)因(yin)素。晶片(pian)內含微處(chu)理器(qi)(qi)為(wei)主機系(xi)統(tong)處(chu)理器(qi)(qi)省下這(zhe)(zhe)(zhe)些(xie)計(ji)(ji)算負(fu)擔.電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)能夠提供剩余(yu)電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)狀態等(deng)信(xin)息(xi)，bq27x00系(xi)列產(chan)品還(huan)提供剩余(yu)可(ke)運行(xing)時間(Run Time to Empty)主機可(ke)隨時向電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)查(cha)詢這(zhe)(zhe)(zhe)些(xie)信(xin)息(xi)，再透過LED指示燈或屏幕顯示將電(dian)(dian)(dian)池(chi)信(xin)息(xi)通知用戶。電(dian)(dian)(dian)量(liang)(liang)(liang)(liang)(liang)檢(jian)(jian)測(ce)計(ji)(ji)的(de)使用非常方便，系(xi)統(tong)處(chu)理器(qi)(qi)僅需(xu)要配置12C或HDQ通信(xin)驅動器(qi)(qi)即(ji)可(ke)。

*電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)描述.圖(tu)4(a)為可選(xuan)(xuan)用(yong)具有(you)鑒(jian)定(ding)功能IC的(de)(de)典型的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組應(ying)用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。根據(ju)所使用(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)檢(jian)(jian)測(ce)(ce)計(ji)IC的(de)(de)不同，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組至(zhi)少(shao)需要有(you)三到四個(ge)外部終端(duan)。VCC及(ji)BAT引腳會(hui)連(lian)到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)，以便為，C供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)測(ce)(ce)量(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)接(jie)地(di)端(duan)連(lian)接(jie)了一個(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)較小的(de)(de)檢(jian)(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器，讓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)檢(jian)(jian)測(ce)(ce)計(ji)的(de)(de)高(gao)阻(zu)(zu)抗SRP及(ji)SRN輸入端(duan)能夠監控感測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)兩端(duan)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)。通過(guo)流(liu)(liu)經檢(jian)(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)可用(yong)來判斷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充入或(huo)釋放的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。設計(ji)人員選(xuan)(xuan)擇檢(jian)(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)時必(bi)須考(kao)慮(lv)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)兩端(duan)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不能超過(guo)100 mV，過(guo)低的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)可能會(hui)在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)較小時產(chan)生誤(wu)差。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)板布局必(bi)須確(que)保從SRP及(ji)SRN到檢(jian)(jian)測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器的(de)(de)連(lian)接(jie)要盡可能靠近(jin)感測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)端(duan)；換言(yan)之，它們(men)應(ying)該是采用(yong)Kelvin連(lian)線。

HDQ引腳需(xu)要外(wai)部上(shang)拉(la)電(dian)(dian)(dian)阻(zu)器(qi)，該電(dian)(dian)(dian)阻(zu)應位于主機或主應用端，這樣電(dian)(dian)(dian)量檢測計才能在電(dian)(dian)(dian)池組與便攜式(shi)設備連接斷(duan)開(kai)時啟用睡眠功能。建議上(shang)拉(la)電(dian)(dian)(dian)阻(zu)值選用10 kΩ。

*電(dian)(dian)池組(zu)鑒(jian)(jian)定。價格低廉的(de)(de)(de)(de)偽冒電(dian)(dian)池的(de)(de)(de)(de)問題(ti)日益嚴重，這(zhe)些電(dian)(dian)池可能不包含(han)OEM廠商要求的(de)(de)(de)(de)安全保護電(dian)(dian)路(lu)。所(suo)以(yi)，真品電(dian)(dian)池組(zu)可包含(han)圖(tu)4(a)所(suo)示的(de)(de)(de)(de)鑒(jian)(jian)定電(dian)(dian)路(lu)。當要鑒(jian)(jian)定電(dian)(dian)池時，主(zhu)(zhu)機(ji)(ji)向含(han)有IC(bq26150，作(zuo)用是(shi)循環冗余校驗(yan)(CRC))的(de)(de)(de)(de)電(dian)(dian)池組(zu)發出一(yi)個(ge)詢問值(zhi)(zhi)(challenge)，電(dian)(dian)池組(zu)所(suo)含(han)的(de)(de)(de)(de)CRC會根據這(zhe)個(ge)詢問值(zhi)(zhi)和，IC中(zhong)(zhong)(zhong)內建的(de)(de)(de)(de)CRC多項式計算這(zhe)個(ge)CRC值(zhi)(zhi)。CRC是(shi)基于主(zhu)(zhu)機(ji)(ji)的(de)(de)(de)(de)查詢命令(ling)與IC中(zhong)(zhong)(zhong)秘密定義的(de)(de)(de)(de)CRC多項式完成的(de)(de)(de)(de)，主(zhu)(zhu)機(ji)(ji)也(ye)會進行(xing)CRC值(zhi)(zhi)計算井(jing)與電(dian)(dian)池組(zu)的(de)(de)(de)(de)計算結(jie)果比較以(yi)確定鑒(jian)(jian)定是(shi)否成功。一(yi)旦(dan)電(dian)(dian)池通過(guo)鑒(jian)(jian)定，bq26150則會發出指(zhi)令(ling)以(yi)確保主(zhu)(zhu)機(ji)(ji)與電(dian)(dian)量檢(jian)測計之(zhi)間的(de)(de)(de)(de)資(zi)料(liao)線路(lu)通訊(xun)正常(chang)。當電(dian)(dian)池連接(jie)中(zhong)(zhong)(zhong)斷或重新連接(jie)時，整個(ge)鑒(jian)(jian)定過(guo)程將重復(fu)一(yi)次。

3.2電(dian)量檢(jian)測算法應用舉例之二(er),能適用于各種通(tong)用電(dian)量計的新型(xing)IC.

當今不少制造廠(chang)商可(ke)(ke)提供種(zhong)類(lei)豐(feng)富的(de)(de)電(dian)(dian)量(liang)計IC,，用戶(hu)(hu)可(ke)(ke)從中選取合適的(de)(de)功能器件，以(yi)優化產品的(de)(de)性價(jia)比(bi)。利用電(dian)(dian)量(liang)計貯(zhu)測(ce)量(liang)的(de)(de)電(dian)(dian)池(chi)參數，這種(zhong)分(fen)離式架構(gou)允許(xu)用戶(hu)(hu)在主機內定(ding)制電(dian)(dian)量(liang)計量(liang)算法(fa)．從而省去電(dian)(dian)池(chi)組內嵌處(chu)理(li)器的(de)(de)成本。值此以(yi)Dallase semicconductor公(gong)司名為例的(de)(de)DS2762芯片作典型分(fen)析. 一新(xin)型分(fen)離式電(dian)(dian)量(liang)計IC,其結構(gou)見圖(tu)5(a)所示.

*DS2762應用特征

DS2762是一(yi)款單節(jie)鋰電(dian)池(chi)電(dian)量計與保(bao)護電(dian)路(lu)(lu)，集成(cheng)(cheng)于一(yi)片微小的(de)(de)2.46mm× 2.74mm倒裝片封裝。由于內(nei)部集成(cheng)(cheng)了用于電(dian)量檢測的(de)(de)高精密電(dian)阻，該款器件非(fei)常節(jie)省空間。它所具有的(de)(de)小尺(chi)寸和無可比擬的(de)(de)高集成(cheng)(cheng)度，對于移(yi)動電(dian)話電(dian)池(chi)組(zu)及其(qi)它類似(si)的(de)(de)手(shou)持產(chan)品，如PDA等(deng)，都非(fei)常理想。集成(cheng)(cheng)的(de)(de)保(bao)護電(dian)路(lu)(lu)連續地監視電(dian)池(chi)的(de)(de)過(guo)壓(ya)、欠壓(ya)和過(guo)流故障(充(chong)電(dian)或放電(dian)期間)。不同于獨立的(de)(de)保(bao)護IC，DS2762允許主(zhu)處(chu)理器監視/控(kong)制保(bao)護FET的(de)(de)導通(tong)狀態(tai)，這樣(yang)，可以通(tong)過(guo)DS2762的(de)(de)保(bao)護電(dian)路(lu)(lu)實現(xian)系統電(dian)源控(kong)制。DS2762也(ye)可以充(chong)電(dian)一(yi)個已(yi)深度消耗(hao)的(de)(de)電(dian)池(chi)，當電(dian)池(chi)電(dian)壓(ya)不足3V時，提供一(yi)條限制電(dian)流的(de)(de)恢復充(chong)電(dian)路(lu)(lu)徑。

DS2762能夠(gou)精(jing)確監視電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)壓和溫(wen)度(du)(du)(du)，其(qi)動(dong)態(tai)范圍(wei)與(yu)分辨(bian)率(lv)滿足任何通(tong)(tong)(tong)行(xing)(xing)的(de)(de)(de)(de)移動(dong)通(tong)(tong)(tong)信(xin)(xin)產品的(de)(de)(de)(de)測(ce)試標準。測(ce)得的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流對內(nei)部(bu)產生的(de)(de)(de)(de)時基進行(xing)(xing)積分，實現電(dian)(dian)(dian)(dian)(dian)量(liang)計量(liang)。通(tong)(tong)(tong)過(guo)實時、連(lian)續的(de)(de)(de)(de)自(zi)動(dong)失調(diao)糾(jiu)正，電(dian)(dian)(dian)(dian)(dian)量(liang)計量(liang)的(de)(de)(de)(de)精(jing)度(du)(du)(du)得以提(ti)高(gao)。內(nei)置(zhi)的(de)(de)(de)(de)檢測(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)消除了因制造(zao)工藝和溫(wen)度(du)(du)(du)而(er)造(zao)成的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)變(bian)化，進一(yi)步提(ti)高(gao)了電(dian)(dian)(dian)(dian)(dian)量(liang)計的(de)(de)(de)(de)精(jing)度(du)(du)(du)。重要(yao)數據(ju)保存于(yu)32字(zi)節、可(ke)加(jia)(jia)鎖的(de)(de)(de)(de)EEPROM；16字(zi)節的(de)(de)(de)(de)SRAM用于(yu)保存動(dong)態(tai)數據(ju)。與(yu)DS2762的(de)(de)(de)(de)所有通(tong)(tong)(tong)信(xin)(xin)均通(tong)(tong)(tong)過(guo)1-Wire、多節點通(tong)(tong)(tong)信(xin)(xin)接口進行(xing)(xing)，最大(da)限度(du)(du)(du)減少(shao)了電(dian)(dian)(dian)(dian)(dian)池組與(yu)主(zhu)機的(de)(de)(de)(de)連(lian)線(xian)。其(qi)主(zhu)要(yao)特征為(wei)；單節鋰電(dian)(dian)(dian)(dian)(dian)池保護器；高(gao)精(jing)度(du)(du)(du)電(dian)(dian)(dian)(dian)(dian)流(電(dian)(dian)(dian)(dian)(dian)量(liang)計量(liang))、電(dian)(dian)(dian)(dian)(dian)壓和溫(wen)度(du)(du)(du)測(ce)量(liang)；可(ke)選的(de)(de)(de)(de)集成25mΩ檢測(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)，每(mei)個DS2762經過(guo)單獨(du)微調(diao)；0V電(dian)(dian)(dian)(dian)(dian)池恢復充電(dian)(dian)(dian)(dian)(dian)；32字(zi)節可(ke)加(jia)(jia)鎖EEPROM，16字(zi)節SRAM，64位ROM；

1-Wire，多(duo)節點，數字通(tong)信接口；支持多(duo)電(dian)(dian)(dian)池組(zu)電(dian)(dian)(dian)源管理，并通(tong)過(guo)保護FET實現系統電(dian)(dian)(dian)源控制；休眠模式(shi)(shi)下電(dian)(dian)(dian)源電(dian)(dian)(dian)流僅(jin)2?A(最(zui)大);工作模式(shi)(shi)下電(dian)(dian)(dian)源電(dian)(dian)(dian)流為90?A(最(zui)大);2.46mm×2.74mm倒裝(zhuang)片封裝(zhuang)或16引(yin)腳下SSOP封裝(zhuang)，兩者均可選擇帶或不帶檢測電(dian)(dian)(dian)阻(zu);復具(ju)有(you)備有(you)評估板.

4、結論

應用好便(bian)攜式電(dian)子(zi)設備的電(dian)池(chi)(chi)技術是選(xuan)(xuan)擇(ze)鋰離子(zi)電(dian)池(chi)(chi)和鋰聚合物電(dian)池(chi)(chi)及其充電(dian)器的基(ji)礎.之于如何正確選(xuan)(xuan)擇(ze),還必須(xu)視便(bian)攜式電(dian)子(zi)備的具體要求而定(ding)。