如今的(de)便(bian)攜(xie)式(shi)(shi)電(dian)(dian)(dian)(dian)子(zi)(zi)備中電(dian)(dian)(dian)(dian)池(chi)技術包(bao)括(kuo)電(dian)(dian)(dian)(dian)量(liang)檢(jian)測算(suan)法、電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)算(suan)法與(yu)(yu)電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)技術等幾(ji)個(ge)方面。眾所周知,充(chong)電(dian)(dian)(dian)(dian)式(shi)(shi)電(dian)(dian)(dian)(dian)池(chi)化學反應有(you)鎳(nie)鎘、鎳(nie)氫(qing)、鋰(li)離子(zi)(zi)和鋰(li)聚合物4種程式(shi)(shi),作(zuo)為(wei)便(bian)攜(xie)式(shi)(shi)電(dian)(dian)(dian)(dian)子(zi)(zi)設備來說,雖然這4種電(dian)(dian)(dian)(dian)池(chi)程式(shi)(shi)各(ge)有(you)特點(dian),但從能量(liang)密度與(yu)(yu)安全性(xing)角(jiao)度的(de)發展與(yu)(yu)實踐可知, 鋰(li)離子(zi)(zi)電(dian)(dian)(dian)(dian)池(chi)和鋰(li)聚合物電(dian)(dian)(dian)(dian)池(chi)的(de)優(you)勢己成為(wei)小型長運(yun)行(xing)時間的(de)設備的(de)理想之選，比如筆(bi)記本電(dian)(dian)(dian)(dian)腦(nao)以及基于(yu)硬盤的(de)PMP等.對便(bian)攜(xie)式(shi)(shi)電(dian)(dian)(dian)(dian)子(zi)(zi)備工(gong)程師(shi)來說，正確選擇與(yu)(yu)應用好便(bian)攜(xie)式(shi)(shi)電(dian)(dian)(dian)(dian)子(zi)(zi)備中電(dian)(dian)(dian)(dian)池(chi)技術至關重要(yao),值此本文(wen)將對此作(zuo)研(yan)討,并(bing)作(zuo)應用舉例分析.

1、關于細流(liu)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(suan)法(fa)

根據最(zui)終(zhong)應用的能(neng)量需求，一(yi)個電(dian)池組(zu)可能(neng)包含(han)最(zui)多(duo)(duo)4個鋰(li)離子(zi)或(huo)鋰(li)聚合物電(dian)池芯,其配(pei)(pei)置(zhi)(zhi)可有(you)多(duo)(duo)種(zhong)變化，同(tong)時帶有(you)一(yi)個主流(liu)的電(dian)源(yuan)適配(pei)(pei)器(qi)：直接(jie)的適配(pei)(pei)器(qi)、USB接(jie)口(kou)或(huo)汽(qi)車充電(dian)器(qi)。除去電(dian)芯數量、電(dian)芯的配(pei)(pei)置(zhi)(zhi)或(huo)電(dian)源(yuan)適配(pei)(pei)器(qi)類型上的差(cha)別，這些電(dian)池組(zu)都有(you)同(tong)樣的充電(dian)特性。因此它們的充電(dian)算法也一(yi)樣。鋰(li)離子(zi)與(yu)鋰(li)聚合物電(dian)池最(zui)好的充電(dian)算法可以分為3個階段(duan)：細(xi)流(liu)充電(dian)、快速充電(dian)和穩定充電(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(ding)電(dian)(dian)壓。在快速(su)充(chong)(chong)電(dian)(dian)過程中，一(yi)旦電(dian)(dian)芯(xin)電(dian)(dian)壓達到(dao)4.2V，穩定(ding)電(dian)(dian)壓階(jie)段就開始了。這(zhe)時(shi)(shi)可(ke)通(tong)過最小充(chong)(chong)電(dian)(dian)電(dian)(dian)流或定(ding)時(shi)(shi)器(qi)或這(zhe)兩者的(de)聯(lian)合來(lai)中斷(duan)充(chong)(chong)電(dian)(dian).當(dang)最小電(dian)(dian)流低于大約0.07C時(shi)(shi)，可(ke)中斷(duan)充(chong)(chong)電(dian)(dian)。定(ding)時(shi)(shi)器(qi)則要靠一(yi)個預(yu)設(she)的(de)定(ding)時(shi)(shi)器(qi)來(lai)觸發中斷(duan)。

高級的電池充電器通常(chang)帶有附(fu)加的安全功(gong)能。比如(ru)，如(ru)果(guo)電(dian)芯溫度超出給定窗口，通常(chang)是0℃--45℃，充電(dian)就(jiu)會暫停。除去某些非(fei)常(chang)低端的設備，現在市面上的鋰離子／鋰聚合(he)物電(dian)池充電(dian)方(fang)案都(dou)集成(cheng)或是帶有外置的元件，以便按照(zhao)充電(dian)特性進行充電(dian)，這(zhe)不(bu)光是為(wei)了取得更佳充電(dian)效果(guo)，同時也(ye)是為(wei)了安全。

2、鋰(li)離子/聚合(he)物(wu)電池充電方案

鋰離子/聚合物電(dian)(dian)池的充電(dian)(dian)方案對(dui)于不(bu)同數量的電(dian)(dian)芯(xin)(xin)、電(dian)(dian)芯(xin)(xin)配(pei)置以及電(dian)(dian)源(yuan)類型(xing)還是(shi)不(bu)同的。目前(qian)主(zhu)要有3種主(zhu)要的充電(dian)(dian)方案：線性，Buck(降壓)開(kai)關和SEPIC(升(sheng)壓與降壓)開(kai)關。

2.1線性方案

當充(chong)電(dian)器(qi)(qi)(qi)輸(shu)入電(dian)壓(ya)大(da)于全(quan)充(chong)滿(man)電(dian)芯加上充(chong)足凈空之后的(de)開路電(dian)壓(ya)時，最(zui)(zui)好用線性(xing)方案(an)(an)，特(te)別是1.0C快速充(chong)電(dian)電(dian)流不(bu)比(bi)1A大(da)太多時。比(bi)如，MP3播放(fang)器(qi)(qi)(qi)通常只有一個電(dian)芯，容量從700到1500mAh不(bu)等，滿(man)充(chong)開路電(dian)壓(ya)是4.2V。MP3播放(fang)機的(de)電(dian)源通常是AC／DC適配器(qi)(qi)(qi)或者是USB接(jie)口，其(qi)輸(shu)出是規(gui)(gui)則(ze)的(de)5V；這時，線性(xing)方案(an)(an)的(de)充(chong)電(dian)器(qi)(qi)(qi)就是最(zui)(zui)簡(jian)單、最(zui)(zui)有效率的(de)方案(an)(an)。圖2所示(shi)為鋰離子(zi)/聚合(he)物電(dian)池充(chong)電(dian)方案(an)(an)線性(xing)方案(an)(an),基本結構和線性(xing)電(dian)壓(ya)規(gui)(gui)整器(qi)(qi)(qi)一樣(yang)。

*線性方(fang)案(an)的(de)(de)充(chong)(chong)電(dian)(dian)(dian)器應(ying)用例舉-雙輸入(ru)Li+充(chong)(chong)電(dian)(dian)(dian)器及智能(neng)電(dian)(dian)(dian)源(yuan)選擇器MAX8677A。MAX8677A是雙輸入(ru)USB/AC適配器線性充(chong)(chong)電(dian)(dian)(dian)器，內置Smart Power Selector，用于(yu)由可充(chong)(chong)電(dian)(dian)(dian)單節Li+電(dian)(dian)(dian)池(chi)供(gong)電(dian)(dian)(dian)的(de)(de)便攜式設(she)(she)備(bei)。該(gai)充(chong)(chong)電(dian)(dian)(dian)器集(ji)成(cheng)了電(dian)(dian)(dian)池(chi)和外(wai)部(bu)電(dian)(dian)(dian)源(yuan)充(chong)(chong)電(dian)(dian)(dian)和切換負(fu)載所需的(de)(de)全部(bu)功(gong)率(lv)開關，因此無需外(wai)部(bu) MOSFET。MAX8677A理想用于(yu)便攜式設(she)(she)備(bei)，例如智能(neng)手機、PDA、便攜式多媒體播放器、GPS導(dao)航設(she)(she)備(bei)、數碼相機、以及數碼攝像機。

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)(dian)(dian)源(yuan)選擇器(qi)自(zi)動(dong)將電(dian)(dian)(dian)(dian)池(chi)切(qie)換到系(xi)統負載，使用系(xi)統未利用的(de)(de)輸入(ru)電(dian)(dian)(dian)(dian)源(yuan)部分為電(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)，充(chong)分利用有限(xian)的(de)(de)USB和(he)適(shi)配器(qi)輸入(ru)電(dian)(dian)(dian)(dian)源(yuan)。所有需要的(de)(de)電(dian)(dian)(dian)(dian)流(liu)檢測(ce)電(dian)(dian)(dian)(dian)路，包括集(ji)成的(de)(de)功(gong)率開(kai)關，均(jun)集(ji)成于(yu)(yu)片上。DC輸入(ru)電(dian)(dian)(dian)(dian)流(liu)限(xian)最高可調(diao)節(jie)(jie)至2A，而DC和(he)USB輸入(ru)均(jun)可支持100mA、500mA、和(he)USB掛(gua)起模式(shi)。充(chong)電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流(liu)可調(diao)節(jie)(jie)至高達1.5A，從而支持 寬范(fan)圍(wei)的(de)(de)電(dian)(dian)(dian)(dian)池(chi)容性(xing)。MAX8677A的(de)(de)其他特性(xing)包括熱(re)調(diao)節(jie)(jie)、過壓保護、充(chong)電(dian)(dian)(dian)(dian)狀態和(he)故(gu)障(zhang)輸出、電(dian)(dian)(dian)(dian)源(yuan)好監視(shi)、電(dian)(dian)(dian)(dian)池(chi)熱(re)敏電(dian)(dian)(dian)(dian)阻監視(shi)、以及充(chong)電(dian)(dian)(dian)(dian)定時器(qi)。MAX8677A采用節(jie)(jie)省空間的(de)(de)、熱(re)增強型、4mm×4mm、24引腳的(de)(de)TQFN封裝(zhuang)，規定工作于(yu)(yu)擴展(zhan)級溫度(du)范(fan)圍(wei)(-40～+85℃)。

2.2 Buck(降壓)開(kai)關方案

當1.0C充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)電(dian)(dian)(dian)(dian)(dian)流大(da)于1A，或(huo)者輸入電(dian)(dian)(dian)(dian)(dian)壓(ya)比電(dian)(dian)(dian)(dian)(dian)芯(xin)(xin)的(de)(de)全充(chong)滿開(kai)路電(dian)(dian)(dian)(dian)(dian)壓(ya)高(gao)(gao)很多(duo)時，Buck或(huo)者降壓(ya)方(fang)案(an)就是(shi)一(yi)個更好的(de)(de)選(xuan)擇。比如，在(zai)(zai)基于硬(ying)盤的(de)(de)PMP中，通(tong)常使用單芯(xin)(xin)鋰離子電(dian)(dian)(dian)(dian)(dian)池(chi)，全充(chong)滿開(kai)路電(dian)(dian)(dian)(dian)(dian)壓(ya)是(shi)4.2V，容量(liang)從(cong)1200到(dao)(dao)2400mAh不等。而現在(zai)(zai)PMP通(tong)常是(shi)用汽(qi)車套(tao)件來充(chong)電(dian)(dian)(dian)(dian)(dian)，它的(de)(de)輸出電(dian)(dian)(dian)(dian)(dian)壓(ya)在(zai)(zai)9V到(dao)(dao)16V之間(jian)。在(zai)(zai)輸入電(dian)(dian)(dian)(dian)(dian)壓(ya)和電(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)壓(ya)之間(jian)比較高(gao)(gao)的(de)(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)差(最小4.8V)會(hui)讓(rang)線性(xing)方(fang)案(an)降低(di)效率。這種低(di)效率，加(jia)上大(da)于1.2A的(de)(de)1C快速(su)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，會(hui)產生(sheng)嚴(yan)重(zhong)的(de)(de)散(san)熱問題。為(wei)(wei)避(bi)免這種情況，就要采(cai)用Buck方(fang)案(an)。圖3為(wei)(wei)鋰電(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)方(fang)案(an)示意圖,基本結構同(tong)Buck(降壓(ya))開(kai)關(guan)電(dian)(dian)(dian)(dian)(dian)壓(ya)調節器(qi)完全相同(tong)。

2.3 SEPIC(升壓(ya)與降(jiang)壓(ya))開關方案(an)

在(zai)(zai)某些使(shi)用3個(ge)甚至(zhi)4個(ge)鋰離子／聚合(he)物電(dian)(dian)(dian)芯串(chuan)聯的設備(bei)中(zhong)，充(chong)電(dian)(dian)(dian)器的輸入(ru)電(dian)(dian)(dian)壓就不(bu)總是(shi)大于電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓。比(bi)如，筆記(ji)本電(dian)(dian)(dian)腦使(shi)用3芯鋰離子電(dian)(dian)(dian)池(chi)組，滿(man)充(chong)開路電(dian)(dian)(dian)壓是(shi)12．6V(4．2V x3)，容(rong)量從1800mAh到3600mAh。輸入(ru)電(dian)(dian)(dian)源(yuan)要么是(shi)輸出電(dian)(dian)(dian)壓1 6V的AC／DC適配器，要么是(shi)汽車套件，輸出電(dian)(dian)(dian)壓在(zai)(zai)9V到16V之間。很顯然地，線性和(he)Buck方案都(dou)不(bu)能為這(zhe)組電(dian)(dian)(dian)池(chi)組充(chong)電(dian)(dian)(dian)。這(zhe)就要用上SEPIC方案，它能在(zai)(zai)輸出電(dian)(dian)(dian)壓高于電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓時工(gong)作，也能在(zai)(zai)輸出電(dian)(dian)(dian)壓低(di)于電(dian)(dian)(dian)池(chi)時工(gong)作。

3、電量檢測算法

許(xu)多可(ke)攜式產品都利用(yong)(yong)電(dian)(dian)壓(ya)測量(liang)(liang)值來估(gu)(gu)計(ji)電(dian)(dian)池(chi)(chi)(chi)剩馀電(dian)(dian)量(liang)(liang)，但是電(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)壓(ya)與剩馀電(dian)(dian)量(liang)(liang)的(de)關系(xi)卻會隨著放電(dian)(dian)率(lv)、溫度和電(dian)(dian)池(chi)(chi)(chi)老化程度而改變，使這種方法的(de)誤差(cha)率(lv)最高可(ke)達50％。市場對(dui)使用(yong)(yong)時間更長的(de)產品需(xu)(xu)求不斷增強，因此系(xi)統設計(ji)人(ren)員(yuan)需(xu)(xu)要更加精(jing)確(que)(que)的(de)解決(jue)方案。使用(yong)(yong)電(dian)(dian)量(liang)(liang)檢測計(ji)吧來測量(liang)(liang)電(dian)(dian)池(chi)(chi)(chi)充人(ren)或消(xiao)耗的(de)電(dian)(dian)量(liang)(liang)，將能夠在很寬(kuan)的(de)應(ying)用(yong)(yong)電(dian)(dian)源級別范圍內提供更精(jing)確(que)(que)的(de)電(dian)(dian)池(chi)(chi)(chi)電(dian)(dian)量(liang)(liang)估(gu)(gu)測。

3.1電(dian)量檢測算法應用(yong)舉例之一,功能(neng)完整的單(dan)＼雙電(dian)池(chi)便攜式(shi)應用(yong)電(dian)池(chi)組設計

*電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)原理.較好的(de)(de)(de)電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)至少要具備電(dian)(dian)池電(dian)(dian)壓(ya)、電(dian)(dian)池組溫度(du)(du)和(he)(he)電(dian)(dian)流(liu)(liu)、測(ce)(ce)(ce)(ce)量(liang)(liang)(liang)方(fang)法；一個(ge)微(wei)(wei)處(chu)理9a；和(he)(he)一套及(ji)業(ye)經驗證的(de)(de)(de)電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)算(suan)法。bq2650x及(ji)bq27x00是功能(neng)完整的(de)(de)(de)電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)，具有一個(ge)測(ce)(ce)(ce)(ce)量(liang)(liang)(liang)電(dian)(dian)壓(ya)與溫度(du)(du)的(de)(de)(de)模數轉換器(ADC)和(he)(he)一個(ge)測(ce)(ce)(ce)(ce)量(liang)(liang)(liang)電(dian)(dian)流(liu)(liu)與充電(dian)(dian)感測(ce)(ce)(ce)(ce)的(de)(de)(de)模數轉換器。這(zhe)些(xie)電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)還具有一個(ge)微(wei)(wei)處(chu)理器，負責(ze)執行德州儀器的(de)(de)(de)電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)算(suan)法。這(zhe)些(xie)演算(suan)法會(hui)補償鋰(li)離子電(dian)(dian)池的(de)(de)(de)自放(fang)電(dian)(dian)、老化、溫度(du)(du)和(he)(he)放(fang)電(dian)(dian)率等因(yin)素。晶(jing)片內含微(wei)(wei)處(chu)理器為主機系(xi)統處(chu)理器省下這(zhe)些(xie)計(ji)(ji)算(suan)負擔.電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)能(neng)夠提供剩余電(dian)(dian)量(liang)(liang)(liang)狀態(tai)等信(xin)息(xi)(xi)，bq27x00系(xi)列(lie)產品還提供剩余可(ke)運行時間(Run Time to Empty)主機可(ke)隨(sui)時向電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)查詢這(zhe)些(xie)信(xin)息(xi)(xi)，再透(tou)過LED指示(shi)燈或屏幕顯(xian)示(shi)將電(dian)(dian)池信(xin)息(xi)(xi)通知用(yong)戶。電(dian)(dian)量(liang)(liang)(liang)檢(jian)測(ce)(ce)(ce)(ce)計(ji)(ji)的(de)(de)(de)使用(yong)非常方(fang)便，系(xi)統處(chu)理器僅需要配置12C或HDQ通信(xin)驅動器即(ji)可(ke)。

*電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組(zu)(zu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路描(miao)述.圖(tu)4(a)為可選(xuan)用(yong)(yong)具(ju)有鑒定功能(neng)(neng)IC的(de)典型的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組(zu)(zu)應用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路。根據(ju)所(suo)使用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量檢(jian)測(ce)(ce)(ce)計(ji)IC的(de)不同(tong)，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)組(zu)(zu)至少(shao)需要有三到四個外(wai)部終端(duan)(duan)(duan)。VCC及(ji)BAT引腳會連(lian)(lian)到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓，以便為，C供(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)及(ji)測(ce)(ce)(ce)量電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)接地端(duan)(duan)(duan)連(lian)(lian)接了一(yi)個電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值(zhi)較小的(de)檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)，讓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量檢(jian)測(ce)(ce)(ce)計(ji)的(de)高阻(zu)抗SRP及(ji)SRN輸入端(duan)(duan)(duan)能(neng)(neng)夠(gou)監控(kong)感(gan)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)兩(liang)端(duan)(duan)(duan)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓。通(tong)過流經(jing)檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流可用(yong)(yong)來判斷(duan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充入或(huo)釋(shi)放的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量。設(she)計(ji)人員(yuan)選(xuan)擇檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值(zhi)時(shi)必(bi)須(xu)(xu)考慮電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)兩(liang)端(duan)(duan)(duan)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓不能(neng)(neng)超過100 mV，過低(di)的(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)值(zhi)可能(neng)(neng)會在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流較小時(shi)產生誤(wu)差。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路板布(bu)局必(bi)須(xu)(xu)確保從(cong)SRP及(ji)SRN到檢(jian)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)器(qi)的(de)連(lian)(lian)接要盡可能(neng)(neng)靠近感(gan)測(ce)(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)端(duan)(duan)(duan)；換言之，它們應該是采(cai)用(yong)(yong)Kelvin連(lian)(lian)線。

HDQ引腳需要外部(bu)上(shang)拉(la)(la)電(dian)阻器，該電(dian)阻應(ying)位于主機(ji)或主應(ying)用端，這樣電(dian)量檢測計(ji)才能(neng)在電(dian)池組與便攜(xie)式(shi)設備連接斷開(kai)時(shi)啟用睡(shui)眠(mian)功能(neng)。建議上(shang)拉(la)(la)電(dian)阻值選用10 kΩ。

*電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)(zu)鑒(jian)定(ding)。價格低廉的(de)偽冒電(dian)(dian)(dian)(dian)(dian)池的(de)問題日(ri)益(yi)嚴重(zhong)，這些電(dian)(dian)(dian)(dian)(dian)池可(ke)能不包含(han)OEM廠商(shang)要求的(de)安全保(bao)護電(dian)(dian)(dian)(dian)(dian)路。所以，真品電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)(zu)可(ke)包含(han)圖4(a)所示的(de)鑒(jian)定(ding)電(dian)(dian)(dian)(dian)(dian)路。當要鑒(jian)定(ding)電(dian)(dian)(dian)(dian)(dian)池時，主機(ji)(ji)向含(han)有(you)IC(bq26150，作(zuo)用是循環(huan)冗(rong)余校驗(yan)(CRC))的(de)電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)(zu)發(fa)出(chu)一(yi)個(ge)詢(xun)問值(challenge)，電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)(zu)所含(han)的(de)CRC會(hui)根據這個(ge)詢(xun)問值和，IC中內建的(de)CRC多項式計(ji)(ji)算這個(ge)CRC值。CRC是基(ji)于主機(ji)(ji)的(de)查詢(xun)命令與IC中秘(mi)密(mi)定(ding)義的(de)CRC多項式完成的(de)，主機(ji)(ji)也會(hui)進行(xing)CRC值計(ji)(ji)算井與電(dian)(dian)(dian)(dian)(dian)池組(zu)(zu)(zu)的(de)計(ji)(ji)算結果(guo)比較以確定(ding)鑒(jian)定(ding)是否成功。一(yi)旦電(dian)(dian)(dian)(dian)(dian)池通過鑒(jian)定(ding)，bq26150則會(hui)發(fa)出(chu)指令以確保(bao)主機(ji)(ji)與電(dian)(dian)(dian)(dian)(dian)量檢測計(ji)(ji)之(zhi)間的(de)資(zi)料線(xian)路通訊(xun)正常。當電(dian)(dian)(dian)(dian)(dian)池連接中斷或重(zhong)新連接時，整個(ge)鑒(jian)定(ding)過程將重(zhong)復一(yi)次。

3.2電(dian)量(liang)檢(jian)測算法應(ying)用(yong)舉例之二,能(neng)適(shi)用(yong)于各(ge)種通用(yong)電(dian)量(liang)計的新型IC.

當今不少制造廠商可提供種類豐(feng)富的(de)(de)電(dian)量(liang)(liang)(liang)計IC,，用戶(hu)可從(cong)中(zhong)選(xuan)取合適的(de)(de)功能器件，以優化產品(pin)的(de)(de)性價比。利用電(dian)量(liang)(liang)(liang)計貯測量(liang)(liang)(liang)的(de)(de)電(dian)池參數，這種分離式(shi)架(jia)構允許用戶(hu)在主機內定制電(dian)量(liang)(liang)(liang)計量(liang)(liang)(liang)算法(fa)．從(cong)而(er)省去電(dian)池組(zu)內嵌處理器的(de)(de)成本。值此以Dallase semicconductor公(gong)司(si)名為(wei)例的(de)(de)DS2762芯片(pian)作典型分析. 一(yi)新型分離式(shi)電(dian)量(liang)(liang)(liang)計IC,其結(jie)構見圖5(a)所(suo)示.

*DS2762應用特征

DS2762是一(yi)款(kuan)單節(jie)鋰電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)量計(ji)與保護(hu)電(dian)(dian)(dian)(dian)路(lu)，集成于(yu)一(yi)片(pian)(pian)微小(xiao)的(de)(de)(de)(de)(de)2.46mm× 2.74mm倒裝(zhuang)片(pian)(pian)封裝(zhuang)。由于(yu)內部集成了用于(yu)電(dian)(dian)(dian)(dian)量檢測的(de)(de)(de)(de)(de)高(gao)精密電(dian)(dian)(dian)(dian)阻，該(gai)款(kuan)器(qi)件非(fei)常(chang)節(jie)省空間(jian)。它(ta)所具有的(de)(de)(de)(de)(de)小(xiao)尺寸和無可(ke)比(bi)擬的(de)(de)(de)(de)(de)高(gao)集成度，對于(yu)移(yi)動電(dian)(dian)(dian)(dian)話電(dian)(dian)(dian)(dian)池組及(ji)其它(ta)類似的(de)(de)(de)(de)(de)手持產(chan)品，如PDA等，都非(fei)常(chang)理想。集成的(de)(de)(de)(de)(de)保護(hu)電(dian)(dian)(dian)(dian)路(lu)連續地監(jian)(jian)視電(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)(de)過(guo)(guo)壓(ya)(ya)、欠壓(ya)(ya)和過(guo)(guo)流故障(zhang)(充(chong)電(dian)(dian)(dian)(dian)或(huo)放(fang)電(dian)(dian)(dian)(dian)期(qi)間(jian))。不(bu)同于(yu)獨(du)立的(de)(de)(de)(de)(de)保護(hu)IC，DS2762允許主處理器(qi)監(jian)(jian)視/控(kong)制保護(hu)FET的(de)(de)(de)(de)(de)導(dao)通狀態，這(zhe)樣，可(ke)以通過(guo)(guo)DS2762的(de)(de)(de)(de)(de)保護(hu)電(dian)(dian)(dian)(dian)路(lu)實現系(xi)統電(dian)(dian)(dian)(dian)源控(kong)制。DS2762也可(ke)以充(chong)電(dian)(dian)(dian)(dian)一(yi)個已深度消耗的(de)(de)(de)(de)(de)電(dian)(dian)(dian)(dian)池，當電(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)壓(ya)(ya)不(bu)足3V時(shi)，提供一(yi)條限制電(dian)(dian)(dian)(dian)流的(de)(de)(de)(de)(de)恢(hui)復(fu)充(chong)電(dian)(dian)(dian)(dian)路(lu)徑。

DS2762能夠精(jing)確監視(shi)電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)流、電(dian)(dian)(dian)(dian)(dian)壓和(he)溫度(du)，其(qi)動態(tai)(tai)范(fan)圍與(yu)(yu)分辨率(lv)滿足任(ren)何通行(xing)(xing)的(de)(de)(de)(de)移動通信(xin)產品(pin)的(de)(de)(de)(de)測(ce)試(shi)標準(zhun)。測(ce)得的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)流對內部產生的(de)(de)(de)(de)時基進(jin)(jin)行(xing)(xing)積分，實現(xian)電(dian)(dian)(dian)(dian)(dian)量(liang)計量(liang)。通過(guo)實時、連續(xu)的(de)(de)(de)(de)自動失調糾正，電(dian)(dian)(dian)(dian)(dian)量(liang)計量(liang)的(de)(de)(de)(de)精(jing)度(du)得以提高(gao)。內置的(de)(de)(de)(de)檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)消除了因制造工藝和(he)溫度(du)而造成(cheng)的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)阻(zu)變化，進(jin)(jin)一步提高(gao)了電(dian)(dian)(dian)(dian)(dian)量(liang)計的(de)(de)(de)(de)精(jing)度(du)。重(zhong)要(yao)數據保存(cun)(cun)于(yu)32字節(jie)、可加(jia)鎖(suo)(suo)的(de)(de)(de)(de)EEPROM；16字節(jie)的(de)(de)(de)(de)SRAM用于(yu)保存(cun)(cun)動態(tai)(tai)數據。與(yu)(yu)DS2762的(de)(de)(de)(de)所有通信(xin)均(jun)通過(guo)1-Wire、多節(jie)點(dian)通信(xin)接口進(jin)(jin)行(xing)(xing)，最大限度(du)減少了電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組與(yu)(yu)主(zhu)機的(de)(de)(de)(de)連線。其(qi)主(zhu)要(yao)特(te)征為；單節(jie)鋰電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)保護器；高(gao)精(jing)度(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(he)溫度(du)測(ce)量(liang)；可選的(de)(de)(de)(de)集成(cheng)25mΩ檢(jian)測(ce)電(dian)(dian)(dian)(dian)(dian)阻(zu)，每(mei)個DS2762經過(guo)單獨微調；0V電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)恢復(fu)充電(dian)(dian)(dian)(dian)(dian)；32字節(jie)可加(jia)鎖(suo)(suo)EEPROM，16字節(jie)SRAM，64位ROM；

1-Wire，多(duo)節點，數字通信接口；支持多(duo)電(dian)池組(zu)電(dian)源管(guan)理(li)，并通過(guo)保護FET實現(xian)系(xi)統電(dian)源控制；休眠模(mo)式(shi)下(xia)電(dian)源電(dian)流(liu)僅(jin)2?A(最大(da));工作模(mo)式(shi)下(xia)電(dian)源電(dian)流(liu)為90?A(最大(da));2.46mm×2.74mm倒裝(zhuang)片封(feng)裝(zhuang)或(huo)16引腳(jiao)下(xia)SSOP封(feng)裝(zhuang)，兩者均可選擇帶或(huo)不(bu)帶檢測電(dian)阻;復具有備有評估板(ban).

4、結論

應用(yong)好便(bian)攜式(shi)電(dian)(dian)子設備的(de)電(dian)(dian)池技術是選(xuan)擇鋰離子電(dian)(dian)池和(he)鋰聚(ju)合物電(dian)(dian)池及其(qi)充電(dian)(dian)器的(de)基礎.之于如何正確(que)選(xuan)擇,還必(bi)須視便(bian)攜式(shi)電(dian)(dian)子備的(de)具體要求而定。