如今的(de)便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子(zi)備中電(dian)(dian)(dian)(dian)池(chi)(chi)技術包括電(dian)(dian)(dian)(dian)量檢測算法、電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)算法與電(dian)(dian)(dian)(dian)池(chi)(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)技術等幾個方(fang)面。眾(zhong)所周知,充(chong)(chong)電(dian)(dian)(dian)(dian)式(shi)電(dian)(dian)(dian)(dian)池(chi)(chi)化學反應(ying)有(you)鎳鎘(ge)、鎳氫、鋰(li)(li)離子(zi)和鋰(li)(li)聚(ju)(ju)合(he)物(wu)4種程(cheng)式(shi),作(zuo)(zuo)為(wei)便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子(zi)設備來說,雖(sui)然這4種電(dian)(dian)(dian)(dian)池(chi)(chi)程(cheng)式(shi)各有(you)特點(dian),但從能(neng)量密(mi)度與安(an)全(quan)性角度的(de)發(fa)展與實踐可知, 鋰(li)(li)離子(zi)電(dian)(dian)(dian)(dian)池(chi)(chi)和鋰(li)(li)聚(ju)(ju)合(he)物(wu)電(dian)(dian)(dian)(dian)池(chi)(chi)的(de)優勢己成為(wei)小型長(chang)運行時間的(de)設備的(de)理(li)想之(zhi)選(xuan)，比(bi)如筆記本電(dian)(dian)(dian)(dian)腦以及基(ji)于硬盤的(de)PMP等.對便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子(zi)備工程(cheng)師來說，正(zheng)確選(xuan)擇與應(ying)用(yong)好(hao)便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子(zi)備中電(dian)(dian)(dian)(dian)池(chi)(chi)技術至關重要(yao),值此(ci)(ci)本文(wen)將對此(ci)(ci)作(zuo)(zuo)研(yan)討(tao),并作(zuo)(zuo)應(ying)用(yong)舉例分析.

1、關于細流充(chong)電(dian)(dian)、快速充(chong)電(dian)(dian)和(he)穩定(ding)充(chong)電(dian)(dian)的電(dian)(dian)池充(chong)電(dian)(dian)算(suan)法

根(gen)據最(zui)終(zhong)應用的(de)能量需求，一個電(dian)池(chi)組可(ke)能包含(han)最(zui)多4個鋰(li)離(li)子或鋰(li)聚(ju)合物電(dian)池(chi)芯,其配(pei)置(zhi)(zhi)可(ke)有多種變化，同時帶(dai)有一個主(zhu)流的(de)電(dian)源(yuan)適配(pei)器：直接(jie)的(de)適配(pei)器、USB接(jie)口或汽車充(chong)(chong)電(dian)器。除去電(dian)芯數量、電(dian)芯的(de)配(pei)置(zhi)(zhi)或電(dian)源(yuan)適配(pei)器類型上的(de)差別，這(zhe)些(xie)電(dian)池(chi)組都有同樣的(de)充(chong)(chong)電(dian)特性。因此它們的(de)充(chong)(chong)電(dian)算法也一樣。鋰(li)離(li)子與鋰(li)聚(ju)合物電(dian)池(chi)最(zui)好的(de)充(chong)(chong)電(dian)算法可(ke)以分為3個階(jie)段：細流充(chong)(chong)電(dian)、快(kuai)速充(chong)(chong)電(dian)和穩定充(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(wen)定(ding)(ding)電(dian)(dian)(dian)(dian)壓(ya)。在快速充(chong)電(dian)(dian)(dian)(dian)過程中(zhong)(zhong)，一(yi)旦電(dian)(dian)(dian)(dian)芯(xin)電(dian)(dian)(dian)(dian)壓(ya)達到4.2V，穩(wen)定(ding)(ding)電(dian)(dian)(dian)(dian)壓(ya)階段就開始了。這(zhe)時可(ke)通過最小充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流或定(ding)(ding)時器(qi)(qi)或這(zhe)兩者的聯合來中(zhong)(zhong)斷充(chong)電(dian)(dian)(dian)(dian).當最小電(dian)(dian)(dian)(dian)流低于大約(yue)0.07C時，可(ke)中(zhong)(zhong)斷充(chong)電(dian)(dian)(dian)(dian)。定(ding)(ding)時器(qi)(qi)則要靠一(yi)個預設的定(ding)(ding)時器(qi)(qi)來觸發中(zhong)(zhong)斷。

高級的電池充電器通常(chang)帶有附(fu)加的(de)(de)安(an)全(quan)功能。比如(ru)，如(ru)果電芯溫(wen)度超出給定窗口(kou)，通常(chang)是0℃--45℃，充(chong)(chong)電就會(hui)暫停(ting)。除去(qu)某些非(fei)常(chang)低端的(de)(de)設備，現(xian)在市面上的(de)(de)鋰離(li)子／鋰聚(ju)合物電池充(chong)(chong)電方案都集(ji)成或是帶有外(wai)置(zhi)的(de)(de)元(yuan)件(jian)，以便(bian)按(an)照(zhao)充(chong)(chong)電特性進行充(chong)(chong)電，這不光是為(wei)了(le)取得更佳充(chong)(chong)電效果，同時(shi)也是為(wei)了(le)安(an)全(quan)。

2、鋰離子(zi)/聚合物電(dian)(dian)池充(chong)電(dian)(dian)方案

鋰離子/聚合物電池的(de)充電方案對于(yu)不同(tong)數量(liang)的(de)電芯、電芯配置以及電源(yuan)類型還是不同(tong)的(de)。目前主要有3種主要的(de)充電方案：線性，Buck(降壓)開關(guan)和(he)SEPIC(升(sheng)壓與降壓)開關(guan)。

2.1線性方案

當充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)輸(shu)入(ru)電(dian)(dian)(dian)壓(ya)大于全充(chong)(chong)滿電(dian)(dian)(dian)芯加(jia)上充(chong)(chong)足凈空之后的(de)(de)(de)開路電(dian)(dian)(dian)壓(ya)時，最(zui)好用線性(xing)(xing)方(fang)(fang)案(an)，特別是(shi)1.0C快速充(chong)(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流不比1A大太多時。比如，MP3播放(fang)器(qi)(qi)通常只有一(yi)個電(dian)(dian)(dian)芯，容(rong)量從700到1500mAh不等(deng)，滿充(chong)(chong)開路電(dian)(dian)(dian)壓(ya)是(shi)4.2V。MP3播放(fang)機的(de)(de)(de)電(dian)(dian)(dian)源通常是(shi)AC／DC適(shi)配器(qi)(qi)或者是(shi)USB接口，其輸(shu)出是(shi)規則的(de)(de)(de)5V；這時，線性(xing)(xing)方(fang)(fang)案(an)的(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)器(qi)(qi)就是(shi)最(zui)簡單、最(zui)有效率的(de)(de)(de)方(fang)(fang)案(an)。圖2所示(shi)為鋰離(li)子/聚(ju)合物電(dian)(dian)(dian)池充(chong)(chong)電(dian)(dian)(dian)方(fang)(fang)案(an)線性(xing)(xing)方(fang)(fang)案(an),基本結構和線性(xing)(xing)電(dian)(dian)(dian)壓(ya)規整器(qi)(qi)一(yi)樣。

*線性(xing)方(fang)案的(de)充(chong)電(dian)(dian)器(qi)(qi)應用(yong)例舉-雙(shuang)輸入(ru)Li+充(chong)電(dian)(dian)器(qi)(qi)及(ji)智(zhi)能電(dian)(dian)源選擇器(qi)(qi)MAX8677A。MAX8677A是(shi)雙(shuang)輸入(ru)USB/AC適配器(qi)(qi)線性(xing)充(chong)電(dian)(dian)器(qi)(qi)，內(nei)置Smart Power Selector，用(yong)于由可充(chong)電(dian)(dian)單(dan)節(jie)Li+電(dian)(dian)池供電(dian)(dian)的(de)便攜式設(she)備。該(gai)充(chong)電(dian)(dian)器(qi)(qi)集成了電(dian)(dian)池和外部(bu)(bu)電(dian)(dian)源充(chong)電(dian)(dian)和切換負載所需的(de)全部(bu)(bu)功率(lv)開關，因此無(wu)需外部(bu)(bu) MOSFET。MAX8677A理想用(yong)于便攜式設(she)備，例如智(zhi)能手機、PDA、便攜式多媒體播(bo)放(fang)器(qi)(qi)、GPS導(dao)航設(she)備、數碼(ma)(ma)相(xiang)機、以及(ji)數碼(ma)(ma)攝像機。

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)源選擇器自(zi)動將(jiang)電(dian)(dian)池(chi)(chi)切換到系統(tong)負載，使用(yong)(yong)系統(tong)未利用(yong)(yong)的(de)(de)輸(shu)入(ru)電(dian)(dian)源部分為電(dian)(dian)池(chi)(chi)充(chong)電(dian)(dian)，充(chong)分利用(yong)(yong)有(you)限(xian)的(de)(de)USB和(he)適配(pei)器輸(shu)入(ru)電(dian)(dian)源。所有(you)需(xu)要的(de)(de)電(dian)(dian)流(liu)檢測電(dian)(dian)路，包(bao)括集(ji)成(cheng)的(de)(de)功率開關，均集(ji)成(cheng)于片(pian)上。DC輸(shu)入(ru)電(dian)(dian)流(liu)限(xian)最(zui)高(gao)可(ke)調節(jie)至2A，而DC和(he)USB輸(shu)入(ru)均可(ke)支持(chi)100mA、500mA、和(he)USB掛起(qi)模式。充(chong)電(dian)(dian)電(dian)(dian)流(liu)可(ke)調節(jie)至高(gao)達(da)1.5A，從而支持(chi) 寬范(fan)圍的(de)(de)電(dian)(dian)池(chi)(chi)容(rong)性。MAX8677A的(de)(de)其他特性包(bao)括熱(re)調節(jie)、過壓(ya)保(bao)護、充(chong)電(dian)(dian)狀態和(he)故障輸(shu)出、電(dian)(dian)源好監(jian)視、電(dian)(dian)池(chi)(chi)熱(re)敏電(dian)(dian)阻監(jian)視、以及充(chong)電(dian)(dian)定時器。MAX8677A采用(yong)(yong)節(jie)省(sheng)空間的(de)(de)、熱(re)增強型、4mm×4mm、24引腳的(de)(de)TQFN封裝，規定工(gong)作(zuo)于擴展級(ji)溫(wen)度范(fan)圍(-40～+85℃)。

2.2 Buck(降壓)開(kai)關方案(an)

當1.0C充電(dian)(dian)(dian)的(de)電(dian)(dian)(dian)流(liu)大于1A，或者輸(shu)入電(dian)(dian)(dian)壓(ya)比(bi)電(dian)(dian)(dian)芯的(de)全(quan)(quan)充滿開路(lu)電(dian)(dian)(dian)壓(ya)高(gao)很多時，Buck或者降壓(ya)方(fang)(fang)案就是一(yi)個更好(hao)的(de)選(xuan)擇(ze)。比(bi)如，在(zai)基(ji)(ji)于硬盤的(de)PMP中，通(tong)常使(shi)用(yong)單芯鋰離子電(dian)(dian)(dian)池，全(quan)(quan)充滿開路(lu)電(dian)(dian)(dian)壓(ya)是4.2V，容(rong)量從1200到2400mAh不等。而現在(zai)PMP通(tong)常是用(yong)汽(qi)車套件來充電(dian)(dian)(dian)，它的(de)輸(shu)出電(dian)(dian)(dian)壓(ya)在(zai)9V到16V之間。在(zai)輸(shu)入電(dian)(dian)(dian)壓(ya)和電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)之間比(bi)較高(gao)的(de)電(dian)(dian)(dian)壓(ya)差(最小4.8V)會(hui)讓線性(xing)方(fang)(fang)案降低(di)效率。這種低(di)效率，加(jia)上大于1.2A的(de)1C快速(su)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)，會(hui)產生嚴重(zhong)的(de)散熱問題。為(wei)避(bi)免這種情(qing)況，就要(yao)采用(yong)Buck方(fang)(fang)案。圖3為(wei)鋰電(dian)(dian)(dian)池充電(dian)(dian)(dian)器(qi)方(fang)(fang)案示(shi)意圖,基(ji)(ji)本結構同Buck(降壓(ya))開關(guan)電(dian)(dian)(dian)壓(ya)調(diao)節器(qi)完全(quan)(quan)相同。

2.3 SEPIC(升(sheng)壓與(yu)降(jiang)壓)開關方案

在某些使用(yong)3個(ge)甚(shen)至4個(ge)鋰離子／聚合(he)物(wu)電(dian)(dian)(dian)(dian)(dian)芯(xin)串聯的設備中(zhong)，充電(dian)(dian)(dian)(dian)(dian)器(qi)的輸(shu)入電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)就(jiu)不總(zong)是(shi)(shi)大于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。比如(ru)，筆(bi)記本電(dian)(dian)(dian)(dian)(dian)腦使用(yong)3芯(xin)鋰離子電(dian)(dian)(dian)(dian)(dian)池(chi)組，滿充開(kai)路電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)(shi)12．6V(4．2V x3)，容量從1800mAh到3600mAh。輸(shu)入電(dian)(dian)(dian)(dian)(dian)源(yuan)要(yao)么是(shi)(shi)輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)1 6V的AC／DC適配器(qi)，要(yao)么是(shi)(shi)汽車套(tao)件，輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)在9V到16V之間。很顯然地，線性和Buck方案都(dou)不能(neng)為(wei)這組電(dian)(dian)(dian)(dian)(dian)池(chi)組充電(dian)(dian)(dian)(dian)(dian)。這就(jiu)要(yao)用(yong)上SEPIC方案，它能(neng)在輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)高(gao)于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)時(shi)(shi)工作，也能(neng)在輸(shu)出(chu)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)低于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)池(chi)時(shi)(shi)工作。

3、電量檢測算法

許多可攜式產品(pin)(pin)都利用電(dian)壓測(ce)量(liang)(liang)(liang)值來估(gu)(gu)計(ji)電(dian)池剩馀(yu)電(dian)量(liang)(liang)(liang)，但(dan)是電(dian)池電(dian)壓與(yu)剩馀(yu)電(dian)量(liang)(liang)(liang)的關系卻會隨著放電(dian)率(lv)、溫度和電(dian)池老化程度而(er)改變，使這種方(fang)法的誤差率(lv)最高可達50％。市場(chang)對(dui)使用時間更長的產品(pin)(pin)需(xu)求不斷增強，因(yin)此系統設計(ji)人員需(xu)要更加精確的解決方(fang)案。使用電(dian)量(liang)(liang)(liang)檢測(ce)計(ji)吧(ba)來測(ce)量(liang)(liang)(liang)電(dian)池充人或(huo)消(xiao)耗的電(dian)量(liang)(liang)(liang)，將(jiang)能夠在(zai)很寬的應用電(dian)源(yuan)級別范圍內提供(gong)更精確的電(dian)池電(dian)量(liang)(liang)(liang)估(gu)(gu)測(ce)。

3.1電量檢測算法應用(yong)舉例(li)之一,功能完整的單＼雙電池(chi)便攜式(shi)應用(yong)電池(chi)組設計

*電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)原理(li).較(jiao)好(hao)的(de)(de)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)至少(shao)要(yao)具(ju)備電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓、電(dian)(dian)(dian)(dian)池組溫度(du)和電(dian)(dian)(dian)(dian)流、測(ce)(ce)量(liang)(liang)(liang)方(fang)法(fa)(fa)；一(yi)個微處(chu)理(li)9a；和一(yi)套及業經驗證的(de)(de)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)算法(fa)(fa)。bq2650x及bq27x00是(shi)功能完(wan)整的(de)(de)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)，具(ju)有(you)一(yi)個測(ce)(ce)量(liang)(liang)(liang)電(dian)(dian)(dian)(dian)壓與溫度(du)的(de)(de)模數轉換(huan)器(qi)(qi)(qi)(qi)(ADC)和一(yi)個測(ce)(ce)量(liang)(liang)(liang)電(dian)(dian)(dian)(dian)流與充電(dian)(dian)(dian)(dian)感測(ce)(ce)的(de)(de)模數轉換(huan)器(qi)(qi)(qi)(qi)。這(zhe)些(xie)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)還具(ju)有(you)一(yi)個微處(chu)理(li)器(qi)(qi)(qi)(qi)，負責執行(xing)德州儀(yi)器(qi)(qi)(qi)(qi)的(de)(de)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)算法(fa)(fa)。這(zhe)些(xie)演算法(fa)(fa)會(hui)補償鋰(li)離子電(dian)(dian)(dian)(dian)池的(de)(de)自放電(dian)(dian)(dian)(dian)、老(lao)化、溫度(du)和放電(dian)(dian)(dian)(dian)率等因(yin)素。晶片(pian)內含微處(chu)理(li)器(qi)(qi)(qi)(qi)為主機系(xi)統(tong)處(chu)理(li)器(qi)(qi)(qi)(qi)省下這(zhe)些(xie)計(ji)(ji)算負擔.電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)能夠提(ti)供(gong)(gong)剩余(yu)(yu)電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)狀態等信(xin)息(xi)，bq27x00系(xi)列產品還提(ti)供(gong)(gong)剩余(yu)(yu)可運行(xing)時(shi)(shi)間(Run Time to Empty)主機可隨時(shi)(shi)向電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)查詢這(zhe)些(xie)信(xin)息(xi)，再透過LED指(zhi)示燈(deng)或(huo)屏(ping)幕顯示將電(dian)(dian)(dian)(dian)池信(xin)息(xi)通知用戶(hu)。電(dian)(dian)(dian)(dian)量(liang)(liang)(liang)檢(jian)(jian)測(ce)(ce)計(ji)(ji)的(de)(de)使用非常方(fang)便，系(xi)統(tong)處(chu)理(li)器(qi)(qi)(qi)(qi)僅需要(yao)配(pei)置12C或(huo)HDQ通信(xin)驅動器(qi)(qi)(qi)(qi)即可。

*電(dian)(dian)(dian)池(chi)(chi)組電(dian)(dian)(dian)路(lu)描述.圖4(a)為可(ke)選用(yong)具有鑒定(ding)功能IC的(de)(de)典型的(de)(de)電(dian)(dian)(dian)池(chi)(chi)組應(ying)用(yong)電(dian)(dian)(dian)路(lu)。根據(ju)所使(shi)用(yong)電(dian)(dian)(dian)量(liang)(liang)檢(jian)測(ce)計IC的(de)(de)不同，電(dian)(dian)(dian)池(chi)(chi)組至(zhi)少需要有三到(dao)四(si)個外部(bu)終端(duan)(duan)(duan)。VCC及(ji)BAT引腳(jiao)會(hui)連(lian)到(dao)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓，以(yi)便為，C供(gong)電(dian)(dian)(dian)及(ji)測(ce)量(liang)(liang)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓。電(dian)(dian)(dian)池(chi)(chi)接(jie)地端(duan)(duan)(duan)連(lian)接(jie)了一個電(dian)(dian)(dian)阻(zu)值(zhi)較小的(de)(de)檢(jian)測(ce)電(dian)(dian)(dian)阻(zu)器，讓電(dian)(dian)(dian)量(liang)(liang)檢(jian)測(ce)計的(de)(de)高阻(zu)抗SRP及(ji)SRN輸入(ru)端(duan)(duan)(duan)能夠監控感測(ce)電(dian)(dian)(dian)阻(zu)兩端(duan)(duan)(duan)的(de)(de)電(dian)(dian)(dian)壓。通過(guo)(guo)流經檢(jian)測(ce)電(dian)(dian)(dian)阻(zu)器的(de)(de)電(dian)(dian)(dian)流可(ke)用(yong)來判(pan)斷(duan)電(dian)(dian)(dian)池(chi)(chi)充入(ru)或釋(shi)放的(de)(de)電(dian)(dian)(dian)量(liang)(liang)。設計人(ren)員選擇檢(jian)測(ce)電(dian)(dian)(dian)阻(zu)值(zhi)時(shi)必須考慮(lv)電(dian)(dian)(dian)阻(zu)兩端(duan)(duan)(duan)的(de)(de)電(dian)(dian)(dian)壓不能超過(guo)(guo)100 mV，過(guo)(guo)低的(de)(de)電(dian)(dian)(dian)阻(zu)值(zhi)可(ke)能會(hui)在電(dian)(dian)(dian)流較小時(shi)產生誤差。電(dian)(dian)(dian)路(lu)板(ban)布局必須確(que)保從(cong)SRP及(ji)SRN到(dao)檢(jian)測(ce)電(dian)(dian)(dian)阻(zu)器的(de)(de)連(lian)接(jie)要盡可(ke)能靠近感測(ce)電(dian)(dian)(dian)阻(zu)端(duan)(duan)(duan)；換言之，它們應(ying)該(gai)是采用(yong)Kelvin連(lian)線。

HDQ引腳需(xu)要外部上(shang)拉電阻器，該電阻應位(wei)于主(zhu)機或主(zhu)應用(yong)端(duan)，這樣電量檢測計才能在電池組與便攜式設備連接斷開時(shi)啟用(yong)睡(shui)眠功能。建議(yi)上(shang)拉電阻值選用(yong)10 kΩ。

*電(dian)池(chi)(chi)(chi)組(zu)鑒(jian)定(ding)。價(jia)格低廉的(de)偽冒電(dian)池(chi)(chi)(chi)的(de)問(wen)題日益嚴(yan)重，這些電(dian)池(chi)(chi)(chi)可(ke)能不包含OEM廠商要(yao)求的(de)安全保(bao)護電(dian)路(lu)。所(suo)以(yi)，真(zhen)品電(dian)池(chi)(chi)(chi)組(zu)可(ke)包含圖(tu)4(a)所(suo)示的(de)鑒(jian)定(ding)電(dian)路(lu)。當(dang)要(yao)鑒(jian)定(ding)電(dian)池(chi)(chi)(chi)時(shi)(shi)，主(zhu)(zhu)機(ji)向含有IC(bq26150，作用是循環冗余校驗(CRC))的(de)電(dian)池(chi)(chi)(chi)組(zu)發(fa)出一(yi)(yi)個(ge)詢(xun)問(wen)值(challenge)，電(dian)池(chi)(chi)(chi)組(zu)所(suo)含的(de)CRC會根據(ju)這個(ge)詢(xun)問(wen)值和，IC中內建的(de)CRC多項式計算(suan)這個(ge)CRC值。CRC是基于主(zhu)(zhu)機(ji)的(de)查詢(xun)命(ming)令(ling)與IC中秘密定(ding)義的(de)CRC多項式完成(cheng)的(de)，主(zhu)(zhu)機(ji)也會進行CRC值計算(suan)井與電(dian)池(chi)(chi)(chi)組(zu)的(de)計算(suan)結(jie)果比較以(yi)確(que)定(ding)鑒(jian)定(ding)是否成(cheng)功。一(yi)(yi)旦電(dian)池(chi)(chi)(chi)通(tong)過鑒(jian)定(ding)，bq26150則會發(fa)出指令(ling)以(yi)確(que)保(bao)主(zhu)(zhu)機(ji)與電(dian)量檢測計之間的(de)資料線路(lu)通(tong)訊正常。當(dang)電(dian)池(chi)(chi)(chi)連接中斷或重新連接時(shi)(shi)，整個(ge)鑒(jian)定(ding)過程將重復(fu)一(yi)(yi)次。

3.2電(dian)量(liang)檢測算法應(ying)用(yong)舉例之二,能適用(yong)于(yu)各種通用(yong)電(dian)量(liang)計(ji)的新型(xing)IC.

當今不少制造廠商可提供種(zhong)類豐(feng)富的(de)(de)電(dian)(dian)(dian)量(liang)(liang)計(ji)(ji)IC,，用(yong)(yong)戶可從中選取合適的(de)(de)功能(neng)器件，以(yi)優化產品(pin)的(de)(de)性價比(bi)。利用(yong)(yong)電(dian)(dian)(dian)量(liang)(liang)計(ji)(ji)貯測量(liang)(liang)的(de)(de)電(dian)(dian)(dian)池參數，這種(zhong)分離式架構允(yun)許用(yong)(yong)戶在主機內定制電(dian)(dian)(dian)量(liang)(liang)計(ji)(ji)量(liang)(liang)算法．從而省去電(dian)(dian)(dian)池組內嵌處理器的(de)(de)成本。值此以(yi)Dallase semicconductor公(gong)司名(ming)為例(li)的(de)(de)DS2762芯片作典(dian)型(xing)分析. 一新型(xing)分離式電(dian)(dian)(dian)量(liang)(liang)計(ji)(ji)IC,其結(jie)構見圖5(a)所示.

*DS2762應用特征

DS2762是(shi)一(yi)款單(dan)節(jie)鋰電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)量(liang)計與保(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)路，集(ji)成(cheng)于一(yi)片微小的(de)2.46mm× 2.74mm倒裝片封裝。由于內部集(ji)成(cheng)了用于電(dian)(dian)(dian)(dian)(dian)量(liang)檢測的(de)高(gao)(gao)精(jing)密電(dian)(dian)(dian)(dian)(dian)阻，該款器(qi)件非常(chang)節(jie)省空間(jian)。它所具有的(de)小尺寸(cun)和(he)無(wu)可比擬的(de)高(gao)(gao)集(ji)成(cheng)度，對于移動電(dian)(dian)(dian)(dian)(dian)話(hua)電(dian)(dian)(dian)(dian)(dian)池組(zu)及(ji)其它類似的(de)手持產品，如PDA等(deng)，都非常(chang)理想。集(ji)成(cheng)的(de)保(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)路連(lian)續地監視電(dian)(dian)(dian)(dian)(dian)池的(de)過壓、欠壓和(he)過流故(gu)障(充(chong)電(dian)(dian)(dian)(dian)(dian)或(huo)放電(dian)(dian)(dian)(dian)(dian)期(qi)間(jian))。不同于獨立的(de)保(bao)(bao)護(hu)(hu)IC，DS2762允許(xu)主處理器(qi)監視/控(kong)制(zhi)保(bao)(bao)護(hu)(hu)FET的(de)導通(tong)狀態，這樣，可以通(tong)過DS2762的(de)保(bao)(bao)護(hu)(hu)電(dian)(dian)(dian)(dian)(dian)路實(shi)現系統(tong)電(dian)(dian)(dian)(dian)(dian)源控(kong)制(zhi)。DS2762也可以充(chong)電(dian)(dian)(dian)(dian)(dian)一(yi)個已深度消耗的(de)電(dian)(dian)(dian)(dian)(dian)池，當電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓不足3V時(shi)，提(ti)供一(yi)條限(xian)制(zhi)電(dian)(dian)(dian)(dian)(dian)流的(de)恢復充(chong)電(dian)(dian)(dian)(dian)(dian)路徑。

DS2762能夠精確監視電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)流(liu)(liu)、電(dian)(dian)(dian)壓和溫(wen)度(du)(du)，其動(dong)態(tai)范圍與(yu)分辨率(lv)滿足任何通行(xing)的(de)(de)移動(dong)通信產品的(de)(de)測試(shi)標準。測得(de)(de)的(de)(de)電(dian)(dian)(dian)流(liu)(liu)對內(nei)(nei)部產生的(de)(de)時基進行(xing)積分，實(shi)(shi)現電(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang)。通過實(shi)(shi)時、連續的(de)(de)自動(dong)失調糾(jiu)正，電(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang)的(de)(de)精度(du)(du)得(de)(de)以提高(gao)。內(nei)(nei)置的(de)(de)檢測電(dian)(dian)(dian)阻消除(chu)了因制(zhi)造(zao)工藝和溫(wen)度(du)(du)而造(zao)成(cheng)的(de)(de)電(dian)(dian)(dian)阻變化，進一步(bu)提高(gao)了電(dian)(dian)(dian)量(liang)(liang)計的(de)(de)精度(du)(du)。重(zhong)要數據(ju)(ju)保存(cun)于32字(zi)節(jie)、可(ke)加鎖(suo)的(de)(de)EEPROM；16字(zi)節(jie)的(de)(de)SRAM用于保存(cun)動(dong)態(tai)數據(ju)(ju)。與(yu)DS2762的(de)(de)所有通信均通過1-Wire、多節(jie)點(dian)通信接(jie)口(kou)進行(xing)，最(zui)大限度(du)(du)減(jian)少了電(dian)(dian)(dian)池(chi)組與(yu)主機的(de)(de)連線。其主要特征為(wei)；單節(jie)鋰電(dian)(dian)(dian)池(chi)保護(hu)器；高(gao)精度(du)(du)電(dian)(dian)(dian)流(liu)(liu)(電(dian)(dian)(dian)量(liang)(liang)計量(liang)(liang))、電(dian)(dian)(dian)壓和溫(wen)度(du)(du)測量(liang)(liang)；可(ke)選的(de)(de)集成(cheng)25mΩ檢測電(dian)(dian)(dian)阻，每(mei)個DS2762經過單獨(du)微調；0V電(dian)(dian)(dian)池(chi)恢復充電(dian)(dian)(dian)；32字(zi)節(jie)可(ke)加鎖(suo)EEPROM，16字(zi)節(jie)SRAM，64位(wei)ROM；

1-Wire，多節(jie)點，數字通信接口；支持多電(dian)(dian)池組(zu)電(dian)(dian)源(yuan)管理，并通過(guo)保護(hu)FET實現(xian)系統電(dian)(dian)源(yuan)控制；休眠模式(shi)下電(dian)(dian)源(yuan)電(dian)(dian)流(liu)僅(jin)2?A(最大);工作模式(shi)下電(dian)(dian)源(yuan)電(dian)(dian)流(liu)為(wei)90?A(最大);2.46mm×2.74mm倒裝(zhuang)(zhuang)片(pian)封(feng)裝(zhuang)(zhuang)或(huo)16引腳下SSOP封(feng)裝(zhuang)(zhuang)，兩者均可選(xuan)擇帶或(huo)不帶檢測電(dian)(dian)阻;復(fu)具有備(bei)有評估板.

4、結論

應用(yong)好便攜式(shi)電子(zi)設備的(de)(de)電池(chi)(chi)技術是選擇鋰離子(zi)電池(chi)(chi)和鋰聚合物(wu)電池(chi)(chi)及其充電器的(de)(de)基礎.之于如何(he)正確選擇,還(huan)必須視便攜式(shi)電子(zi)備的(de)(de)具體要求而定。