如(ru)今的(de)(de)(de)便(bian)攜式(shi)電(dian)子(zi)(zi)(zi)備中(zhong)電(dian)池(chi)(chi)技(ji)術(shu)包括電(dian)量(liang)檢測算法(fa)、電(dian)池(chi)(chi)充(chong)電(dian)算法(fa)與(yu)電(dian)池(chi)(chi)充(chong)電(dian)技(ji)術(shu)等幾(ji)個方(fang)面(mian)。眾(zhong)所周知(zhi)(zhi),充(chong)電(dian)式(shi)電(dian)池(chi)(chi)化學反應有鎳鎘、鎳氫、鋰(li)(li)離子(zi)(zi)(zi)和(he)鋰(li)(li)聚(ju)合物(wu)4種(zhong)程式(shi),作為(wei)便(bian)攜式(shi)電(dian)子(zi)(zi)(zi)設(she)備來說,雖然這(zhe)4種(zhong)電(dian)池(chi)(chi)程式(shi)各有特點(dian),但從能量(liang)密度與(yu)安全性(xing)角度的(de)(de)(de)發展(zhan)與(yu)實踐可(ke)知(zhi)(zhi), 鋰(li)(li)離子(zi)(zi)(zi)電(dian)池(chi)(chi)和(he)鋰(li)(li)聚(ju)合物(wu)電(dian)池(chi)(chi)的(de)(de)(de)優(you)勢己成為(wei)小型(xing)長運(yun)行時(shi)間的(de)(de)(de)設(she)備的(de)(de)(de)理想(xiang)之選(xuan)，比如(ru)筆(bi)記本電(dian)腦(nao)以(yi)及基于(yu)硬盤的(de)(de)(de)PMP等.對(dui)便(bian)攜式(shi)電(dian)子(zi)(zi)(zi)備工程師來說，正確選(xuan)擇(ze)與(yu)應用好便(bian)攜式(shi)電(dian)子(zi)(zi)(zi)備中(zhong)電(dian)池(chi)(chi)技(ji)術(shu)至關重要,值此(ci)本文將對(dui)此(ci)作研討(tao),并(bing)作應用舉例分析.

1、關(guan)于細流充電(dian)、快速充電(dian)和穩定充電(dian)的電(dian)池充電(dian)算(suan)法(fa)

根據最終(zhong)應(ying)用的能(neng)量需求，一個(ge)(ge)電(dian)(dian)(dian)(dian)池(chi)組(zu)可能(neng)包含最多4個(ge)(ge)鋰(li)離子或鋰(li)聚合物電(dian)(dian)(dian)(dian)池(chi)芯(xin),其配(pei)(pei)置可有多種變化(hua)，同(tong)時帶有一個(ge)(ge)主流(liu)的電(dian)(dian)(dian)(dian)源適配(pei)(pei)器：直接的適配(pei)(pei)器、USB接口或汽車(che)充電(dian)(dian)(dian)(dian)器。除去電(dian)(dian)(dian)(dian)芯(xin)數量、電(dian)(dian)(dian)(dian)芯(xin)的配(pei)(pei)置或電(dian)(dian)(dian)(dian)源適配(pei)(pei)器類型上的差別(bie)，這些電(dian)(dian)(dian)(dian)池(chi)組(zu)都有同(tong)樣(yang)的充電(dian)(dian)(dian)(dian)特性。因此它們的充電(dian)(dian)(dian)(dian)算(suan)法(fa)(fa)也一樣(yang)。鋰(li)離子與鋰(li)聚合物電(dian)(dian)(dian)(dian)池(chi)最好的充電(dian)(dian)(dian)(dian)算(suan)法(fa)(fa)可以分為(wei)3個(ge)(ge)階段(duan)：細流(liu)充電(dian)(dian)(dian)(dian)、快(kuai)速充電(dian)(dian)(dian)(dian)和穩定充電(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。
*穩定(ding)(ding)電(dian)壓(ya)(ya)。在快速充(chong)電(dian)過程中(zhong)，一(yi)旦電(dian)芯電(dian)壓(ya)(ya)達(da)到4.2V，穩定(ding)(ding)電(dian)壓(ya)(ya)階段就開始了。這(zhe)時(shi)可(ke)通(tong)過最(zui)小充(chong)電(dian)電(dian)流或定(ding)(ding)時(shi)器或這(zhe)兩者(zhe)的聯合來中(zhong)斷充(chong)電(dian).當最(zui)小電(dian)流低于大(da)約(yue)0.07C時(shi)，可(ke)中(zhong)斷充(chong)電(dian)。定(ding)(ding)時(shi)器則要靠一(yi)個(ge)預設(she)的定(ding)(ding)時(shi)器來觸發中(zhong)斷。

高級的電池充電器通常(chang)帶(dai)有(you)附加的(de)安(an)全功(gong)能(neng)。比如，如果電(dian)(dian)(dian)(dian)芯(xin)溫(wen)度(du)超出給定窗口，通常(chang)是0℃--45℃，充(chong)電(dian)(dian)(dian)(dian)就(jiu)會暫停(ting)。除去某些非常(chang)低端的(de)設備(bei)，現在市(shi)面上的(de)鋰(li)離(li)子／鋰(li)聚合物(wu)電(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)方案都(dou)集成或是帶(dai)有(you)外置的(de)元件，以便按照充(chong)電(dian)(dian)(dian)(dian)特性進行充(chong)電(dian)(dian)(dian)(dian)，這(zhe)不光是為了(le)取得更佳充(chong)電(dian)(dian)(dian)(dian)效果，同時也(ye)是為了(le)安(an)全。

2、鋰離子/聚合物電(dian)池(chi)充電(dian)方案

鋰離(li)子/聚合物電(dian)池的充(chong)電(dian)方案對于不同(tong)數量(liang)的電(dian)芯、電(dian)芯配置以及電(dian)源類型還是不同(tong)的。目前主要有3種主要的充(chong)電(dian)方案：線性，Buck(降(jiang)(jiang)壓)開關和(he)SEPIC(升(sheng)壓與降(jiang)(jiang)壓)開關。

2.1線性方案

當充(chong)(chong)(chong)(chong)電(dian)器輸入電(dian)壓(ya)大于(yu)全(quan)充(chong)(chong)(chong)(chong)滿電(dian)芯加上充(chong)(chong)(chong)(chong)足凈(jing)空(kong)之后的開路(lu)電(dian)壓(ya)時(shi)，最好用線性(xing)方(fang)(fang)案，特(te)別是(shi)1.0C快速充(chong)(chong)(chong)(chong)電(dian)電(dian)流不比1A大太多時(shi)。比如，MP3播放器通常(chang)只(zhi)有一個電(dian)芯，容量從700到1500mAh不等，滿充(chong)(chong)(chong)(chong)開路(lu)電(dian)壓(ya)是(shi)4.2V。MP3播放機(ji)的電(dian)源通常(chang)是(shi)AC／DC適配器或者是(shi)USB接口(kou)，其輸出是(shi)規則的5V；這(zhe)時(shi)，線性(xing)方(fang)(fang)案的充(chong)(chong)(chong)(chong)電(dian)器就是(shi)最簡單、最有效率的方(fang)(fang)案。圖2所(suo)示為(wei)鋰離(li)子/聚合物電(dian)池充(chong)(chong)(chong)(chong)電(dian)方(fang)(fang)案線性(xing)方(fang)(fang)案,基本結構(gou)和線性(xing)電(dian)壓(ya)規整(zheng)器一樣。

*線性方案(an)的(de)充(chong)(chong)電(dian)(dian)(dian)器應(ying)用例(li)舉-雙(shuang)輸入(ru)Li+充(chong)(chong)電(dian)(dian)(dian)器及智(zhi)能電(dian)(dian)(dian)源選擇器MAX8677A。MAX8677A是雙(shuang)輸入(ru)USB/AC適配(pei)器線性充(chong)(chong)電(dian)(dian)(dian)器，內(nei)置(zhi)Smart Power Selector，用于由可充(chong)(chong)電(dian)(dian)(dian)單節Li+電(dian)(dian)(dian)池(chi)供(gong)電(dian)(dian)(dian)的(de)便(bian)攜式(shi)(shi)(shi)設備。該充(chong)(chong)電(dian)(dian)(dian)器集(ji)成了電(dian)(dian)(dian)池(chi)和(he)(he)外部(bu)電(dian)(dian)(dian)源充(chong)(chong)電(dian)(dian)(dian)和(he)(he)切(qie)換負載所(suo)需(xu)的(de)全部(bu)功率開(kai)關，因此無需(xu)外部(bu) MOSFET。MAX8677A理想(xiang)用于便(bian)攜式(shi)(shi)(shi)設備，例(li)如智(zhi)能手機、PDA、便(bian)攜式(shi)(shi)(shi)多媒體播放器、GPS導航設備、數碼(ma)(ma)相機、以及數碼(ma)(ma)攝像(xiang)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)(dian)源(yuan)選擇(ze)器自動將(jiang)電(dian)(dian)(dian)(dian)(dian)池切換到系統負載，使用(yong)系統未利用(yong)的(de)(de)輸(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)源(yuan)部分為(wei)電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)，充(chong)分利用(yong)有(you)限的(de)(de)USB和適配(pei)器輸(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)源(yuan)。所有(you)需要的(de)(de)電(dian)(dian)(dian)(dian)(dian)流(liu)檢測電(dian)(dian)(dian)(dian)(dian)路，包(bao)括集成的(de)(de)功(gong)率開關，均集成于(yu)片上。DC輸(shu)(shu)入(ru)電(dian)(dian)(dian)(dian)(dian)流(liu)限最高可調(diao)(diao)節至2A，而DC和USB輸(shu)(shu)入(ru)均可支(zhi)持(chi)100mA、500mA、和USB掛起模(mo)式。充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)可調(diao)(diao)節至高達1.5A，從而支(zhi)持(chi) 寬范圍的(de)(de)電(dian)(dian)(dian)(dian)(dian)池容性(xing)。MAX8677A的(de)(de)其(qi)他特性(xing)包(bao)括熱(re)調(diao)(diao)節、過(guo)壓保護、充(chong)電(dian)(dian)(dian)(dian)(dian)狀(zhuang)態和故障輸(shu)(shu)出、電(dian)(dian)(dian)(dian)(dian)源(yuan)好監視、電(dian)(dian)(dian)(dian)(dian)池熱(re)敏電(dian)(dian)(dian)(dian)(dian)阻監視、以及充(chong)電(dian)(dian)(dian)(dian)(dian)定時器。MAX8677A采用(yong)節省空(kong)間的(de)(de)、熱(re)增強(qiang)型(xing)、4mm×4mm、24引腳(jiao)的(de)(de)TQFN封裝，規定工作(zuo)于(yu)擴展級溫(wen)度范圍(-40～+85℃)。

2.2 Buck(降壓)開關方(fang)案

當1.0C充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)電(dian)(dian)(dian)(dian)(dian)流(liu)大于(yu)1A，或(huo)者(zhe)輸(shu)(shu)入電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)比(bi)電(dian)(dian)(dian)(dian)(dian)芯的(de)全(quan)充(chong)滿開(kai)路電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)高很(hen)多時，Buck或(huo)者(zhe)降壓(ya)(ya)方案(an)就是(shi)一個(ge)更(geng)好的(de)選擇。比(bi)如，在基于(yu)硬盤的(de)PMP中，通常(chang)使用(yong)單芯鋰(li)(li)離(li)子電(dian)(dian)(dian)(dian)(dian)池，全(quan)充(chong)滿開(kai)路電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)是(shi)4.2V，容量從1200到2400mAh不等。而現在PMP通常(chang)是(shi)用(yong)汽車套(tao)件(jian)來(lai)充(chong)電(dian)(dian)(dian)(dian)(dian)，它的(de)輸(shu)(shu)出電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)在9V到16V之(zhi)間。在輸(shu)(shu)入電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)和電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)之(zhi)間比(bi)較高的(de)電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)差(cha)(最小(xiao)4.8V)會讓線性方案(an)降低(di)效率(lv)。這種低(di)效率(lv)，加上(shang)大于(yu)1.2A的(de)1C快速(su)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流(liu)，會產生嚴重的(de)散熱問題。為避免這種情況，就要采用(yong)Buck方案(an)。圖3為鋰(li)(li)電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)器(qi)方案(an)示意圖,基本結構(gou)同(tong)(tong)Buck(降壓(ya)(ya))開(kai)關電(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)調節器(qi)完全(quan)相(xiang)同(tong)(tong)。

2.3 SEPIC(升壓與降(jiang)壓)開關方案

在(zai)某些(xie)使用3個甚至4個鋰離子／聚合物電(dian)(dian)(dian)芯(xin)串聯(lian)的(de)設備中，充電(dian)(dian)(dian)器的(de)輸(shu)入(ru)電(dian)(dian)(dian)壓(ya)(ya)(ya)就不總(zong)是大(da)于電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)(ya)。比如(ru)，筆記本電(dian)(dian)(dian)腦使用3芯(xin)鋰離子電(dian)(dian)(dian)池組，滿充開路電(dian)(dian)(dian)壓(ya)(ya)(ya)是12．6V(4．2V x3)，容(rong)量從1800mAh到3600mAh。輸(shu)入(ru)電(dian)(dian)(dian)源要(yao)么(me)是輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)1 6V的(de)AC／DC適配器，要(yao)么(me)是汽車套(tao)件，輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)在(zai)9V到16V之間。很(hen)顯然地，線(xian)性和Buck方案都不能(neng)為這組電(dian)(dian)(dian)池組充電(dian)(dian)(dian)。這就要(yao)用上SEPIC方案，它能(neng)在(zai)輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)高(gao)于電(dian)(dian)(dian)池電(dian)(dian)(dian)壓(ya)(ya)(ya)時(shi)工作，也能(neng)在(zai)輸(shu)出(chu)電(dian)(dian)(dian)壓(ya)(ya)(ya)低(di)于電(dian)(dian)(dian)池時(shi)工作。

3、電量檢測算法

許(xu)多可(ke)攜式產品(pin)都利用電(dian)(dian)(dian)壓測量(liang)值來估計電(dian)(dian)(dian)池(chi)(chi)剩(sheng)馀(yu)電(dian)(dian)(dian)量(liang)，但(dan)是電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)壓與剩(sheng)馀(yu)電(dian)(dian)(dian)量(liang)的(de)(de)(de)(de)關系(xi)(xi)卻會隨(sui)著放電(dian)(dian)(dian)率(lv)、溫(wen)度和電(dian)(dian)(dian)池(chi)(chi)老化程度而改(gai)變，使(shi)這種方法的(de)(de)(de)(de)誤差(cha)率(lv)最(zui)高(gao)可(ke)達(da)50％。市場對(dui)使(shi)用時間更長的(de)(de)(de)(de)產品(pin)需求不斷增(zeng)強，因此系(xi)(xi)統(tong)設計人員需要(yao)更加精確的(de)(de)(de)(de)解決方案。使(shi)用電(dian)(dian)(dian)量(liang)檢測計吧來測量(liang)電(dian)(dian)(dian)池(chi)(chi)充(chong)人或消耗(hao)的(de)(de)(de)(de)電(dian)(dian)(dian)量(liang)，將(jiang)能夠在很寬的(de)(de)(de)(de)應用電(dian)(dian)(dian)源(yuan)級(ji)別(bie)范(fan)圍內提供更精確的(de)(de)(de)(de)電(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)量(liang)估測。

3.1電(dian)量檢測算(suan)法(fa)應(ying)用舉例(li)之一,功(gong)能完整的單＼雙(shuang)電(dian)池便攜式應(ying)用電(dian)池組設計(ji)

*電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)原理(li).較好的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)至少要(yao)具備(bei)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓、電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池組溫度(du)(du)和(he)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)、測(ce)(ce)(ce)(ce)量(liang)(liang)方(fang)(fang)法(fa)；一個(ge)微(wei)(wei)處理(li)9a；和(he)一套(tao)及(ji)業經驗證的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)算(suan)法(fa)。bq2650x及(ji)bq27x00是功(gong)能完整的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)，具有一個(ge)測(ce)(ce)(ce)(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓與溫度(du)(du)的(de)(de)(de)模數轉換器(ADC)和(he)一個(ge)測(ce)(ce)(ce)(ce)量(liang)(liang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)與充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)感測(ce)(ce)(ce)(ce)的(de)(de)(de)模數轉換器。這些(xie)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)還(huan)具有一個(ge)微(wei)(wei)處理(li)器，負責(ze)執行(xing)德州(zhou)儀器的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)算(suan)法(fa)。這些(xie)演算(suan)法(fa)會(hui)補償鋰(li)離子(zi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)自(zi)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)、老化(hua)、溫度(du)(du)和(he)放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)率等因素。晶片內含微(wei)(wei)處理(li)器為主(zhu)機系(xi)(xi)統處理(li)器省(sheng)下這些(xie)計(ji)算(suan)負擔.電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)能夠提供剩(sheng)(sheng)余(yu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)狀態(tai)等信息(xi)，bq27x00系(xi)(xi)列產品(pin)還(huan)提供剩(sheng)(sheng)余(yu)可運行(xing)時(shi)間(Run Time to Empty)主(zhu)機可隨時(shi)向電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)查詢這些(xie)信息(xi)，再(zai)透過LED指示(shi)燈或屏幕顯示(shi)將電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池信息(xi)通(tong)知(zhi)用戶。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)(liang)檢(jian)(jian)測(ce)(ce)(ce)(ce)計(ji)的(de)(de)(de)使用非常方(fang)(fang)便，系(xi)(xi)統處理(li)器僅需要(yao)配置12C或HDQ通(tong)信驅動(dong)器即可。

*電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路描述(shu).圖4(a)為(wei)可(ke)選用具有鑒定功能IC的(de)(de)(de)典(dian)型的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組應(ying)用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路。根據所(suo)使用電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)檢測(ce)(ce)計(ji)IC的(de)(de)(de)不(bu)同，電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組至少需(xu)要有三(san)到四個(ge)(ge)外部終端。VCC及BAT引腳會連(lian)到電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)，以(yi)便為(wei)，C供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)及測(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)(ya)。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)接(jie)地(di)端連(lian)接(jie)了一個(ge)(ge)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)(zhi)較小的(de)(de)(de)檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)，讓電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)檢測(ce)(ce)計(ji)的(de)(de)(de)高阻(zu)(zu)抗SRP及SRN輸入端能夠監控(kong)感測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)兩(liang)端的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)。通過流經(jing)檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流可(ke)用來判斷電(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)充入或釋放的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。設(she)計(ji)人(ren)員選擇檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)(zhi)時必須考(kao)慮電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)兩(liang)端的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)(ya)不(bu)能超過100 mV，過低的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)值(zhi)(zhi)可(ke)能會在電(dian)(dian)(dian)(dian)(dian)(dian)(dian)流較小時產生(sheng)誤差。電(dian)(dian)(dian)(dian)(dian)(dian)(dian)路板布局(ju)必須確保從SRP及SRN到檢測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)器(qi)的(de)(de)(de)連(lian)接(jie)要盡可(ke)能靠近感測(ce)(ce)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)(zu)端；換言之，它們應(ying)該是采用Kelvin連(lian)線。

HDQ引腳需要外部(bu)上(shang)拉電(dian)阻(zu)器，該電(dian)阻(zu)應位于主(zhu)機或主(zhu)應用(yong)(yong)端，這樣電(dian)量檢測計才能(neng)在電(dian)池組(zu)與便(bian)攜式設(she)備連接斷開時啟用(yong)(yong)睡眠功能(neng)。建議上(shang)拉電(dian)阻(zu)值選用(yong)(yong)10 kΩ。

*電(dian)(dian)(dian)(dian)(dian)池(chi)組鑒定(ding)(ding)。價格低(di)廉的(de)(de)(de)偽(wei)冒電(dian)(dian)(dian)(dian)(dian)池(chi)的(de)(de)(de)問(wen)題日益嚴重，這(zhe)些電(dian)(dian)(dian)(dian)(dian)池(chi)可(ke)能不(bu)包含(han)OEM廠商要求的(de)(de)(de)安全保護電(dian)(dian)(dian)(dian)(dian)路(lu)。所(suo)(suo)以，真品電(dian)(dian)(dian)(dian)(dian)池(chi)組可(ke)包含(han)圖4(a)所(suo)(suo)示的(de)(de)(de)鑒定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)路(lu)。當要鑒定(ding)(ding)電(dian)(dian)(dian)(dian)(dian)池(chi)時，主機(ji)(ji)向含(han)有(you)IC(bq26150，作用是循環冗(rong)余校(xiao)驗(CRC))的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池(chi)組發出(chu)一(yi)個(ge)(ge)詢(xun)問(wen)值(zhi)(challenge)，電(dian)(dian)(dian)(dian)(dian)池(chi)組所(suo)(suo)含(han)的(de)(de)(de)CRC會(hui)根(gen)據這(zhe)個(ge)(ge)詢(xun)問(wen)值(zhi)和，IC中(zhong)內建的(de)(de)(de)CRC多項(xiang)式(shi)計(ji)(ji)算這(zhe)個(ge)(ge)CRC值(zhi)。CRC是基于主機(ji)(ji)的(de)(de)(de)查詢(xun)命令(ling)(ling)與IC中(zhong)秘密(mi)定(ding)(ding)義的(de)(de)(de)CRC多項(xiang)式(shi)完成(cheng)的(de)(de)(de)，主機(ji)(ji)也會(hui)進行CRC值(zhi)計(ji)(ji)算井與電(dian)(dian)(dian)(dian)(dian)池(chi)組的(de)(de)(de)計(ji)(ji)算結果比較以確(que)定(ding)(ding)鑒定(ding)(ding)是否成(cheng)功。一(yi)旦電(dian)(dian)(dian)(dian)(dian)池(chi)通過鑒定(ding)(ding)，bq26150則會(hui)發出(chu)指令(ling)(ling)以確(que)保主機(ji)(ji)與電(dian)(dian)(dian)(dian)(dian)量檢測計(ji)(ji)之間的(de)(de)(de)資料線路(lu)通訊正常(chang)。當電(dian)(dian)(dian)(dian)(dian)池(chi)連(lian)接中(zhong)斷或(huo)重新連(lian)接時，整個(ge)(ge)鑒定(ding)(ding)過程將重復一(yi)次。

3.2電(dian)量(liang)檢測算法應(ying)用(yong)舉例之二,能適(shi)用(yong)于各種通用(yong)電(dian)量(liang)計的新型IC.

當今不(bu)少(shao)制造廠商可(ke)提供種類豐(feng)富的(de)(de)(de)(de)電(dian)量計IC,，用戶(hu)可(ke)從中(zhong)選取合適的(de)(de)(de)(de)功(gong)能器件，以優(you)化產品的(de)(de)(de)(de)性(xing)價比。利(li)用電(dian)量計貯測量的(de)(de)(de)(de)電(dian)池參數，這種分(fen)(fen)離式(shi)架構允許(xu)用戶(hu)在主機(ji)內定制電(dian)量計量算法．從而省去電(dian)池組(zu)內嵌處(chu)理器的(de)(de)(de)(de)成本(ben)。值(zhi)此以Dallase semicconductor公(gong)司(si)名(ming)為例的(de)(de)(de)(de)DS2762芯片作典型分(fen)(fen)析. 一新型分(fen)(fen)離式(shi)電(dian)量計IC,其結構見圖5(a)所示(shi).

*DS2762應用特征

DS2762是一(yi)款單(dan)節鋰電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)量計與保(bao)護(hu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)，集(ji)成(cheng)于(yu)(yu)一(yi)片(pian)微(wei)小(xiao)的(de)(de)(de)2.46mm× 2.74mm倒裝(zhuang)片(pian)封裝(zhuang)。由于(yu)(yu)內部集(ji)成(cheng)了用(yong)于(yu)(yu)電(dian)(dian)(dian)(dian)(dian)(dian)量檢測的(de)(de)(de)高精密電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)，該款器(qi)件非常節省空(kong)間。它所具有的(de)(de)(de)小(xiao)尺寸和(he)無可(ke)比擬的(de)(de)(de)高集(ji)成(cheng)度(du)，對于(yu)(yu)移動電(dian)(dian)(dian)(dian)(dian)(dian)話電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)組(zu)及其它類似的(de)(de)(de)手持產品，如PDA等，都非常理(li)想(xiang)。集(ji)成(cheng)的(de)(de)(de)保(bao)護(hu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)連續(xu)地監視(shi)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)的(de)(de)(de)過壓(ya)、欠壓(ya)和(he)過流故障(zhang)(充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)或放電(dian)(dian)(dian)(dian)(dian)(dian)期間)。不同(tong)于(yu)(yu)獨(du)立的(de)(de)(de)保(bao)護(hu)IC，DS2762允許(xu)主處理(li)器(qi)監視(shi)/控(kong)制保(bao)護(hu)FET的(de)(de)(de)導通(tong)狀(zhuang)態(tai)，這樣，可(ke)以通(tong)過DS2762的(de)(de)(de)保(bao)護(hu)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)實現系(xi)統電(dian)(dian)(dian)(dian)(dian)(dian)源控(kong)制。DS2762也可(ke)以充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)一(yi)個已(yi)深(shen)度(du)消耗的(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)，當電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)壓(ya)不足3V時，提供一(yi)條限制電(dian)(dian)(dian)(dian)(dian)(dian)流的(de)(de)(de)恢(hui)復充(chong)電(dian)(dian)(dian)(dian)(dian)(dian)路(lu)徑。

DS2762能夠精確監視電(dian)池(chi)(chi)電(dian)流(liu)(liu)、電(dian)壓(ya)和溫(wen)度(du)，其動態(tai)范圍與(yu)分辨率滿足任何通行(xing)(xing)的(de)(de)(de)移(yi)動通信產品的(de)(de)(de)測(ce)試標準。測(ce)得(de)的(de)(de)(de)電(dian)流(liu)(liu)對內部產生(sheng)的(de)(de)(de)時基(ji)進行(xing)(xing)積(ji)分，實現(xian)電(dian)量(liang)(liang)計量(liang)(liang)。通過(guo)實時、連續(xu)的(de)(de)(de)自(zi)動失(shi)調(diao)糾(jiu)正，電(dian)量(liang)(liang)計量(liang)(liang)的(de)(de)(de)精度(du)得(de)以提(ti)高(gao)。內置(zhi)的(de)(de)(de)檢(jian)測(ce)電(dian)阻(zu)消除(chu)了因制(zhi)造工藝和溫(wen)度(du)而(er)造成(cheng)的(de)(de)(de)電(dian)阻(zu)變化，進一步(bu)提(ti)高(gao)了電(dian)量(liang)(liang)計的(de)(de)(de)精度(du)。重要(yao)數據保存于32字(zi)節(jie)、可加鎖的(de)(de)(de)EEPROM；16字(zi)節(jie)的(de)(de)(de)SRAM用(yong)于保存動態(tai)數據。與(yu)DS2762的(de)(de)(de)所有(you)通信均(jun)通過(guo)1-Wire、多節(jie)點(dian)通信接口進行(xing)(xing)，最(zui)大(da)限(xian)度(du)減少了電(dian)池(chi)(chi)組與(yu)主(zhu)機的(de)(de)(de)連線。其主(zhu)要(yao)特征為；單(dan)(dan)節(jie)鋰電(dian)池(chi)(chi)保護器(qi)；高(gao)精度(du)電(dian)流(liu)(liu)(電(dian)量(liang)(liang)計量(liang)(liang))、電(dian)壓(ya)和溫(wen)度(du)測(ce)量(liang)(liang)；可選的(de)(de)(de)集成(cheng)25mΩ檢(jian)測(ce)電(dian)阻(zu)，每(mei)個(ge)DS2762經(jing)過(guo)單(dan)(dan)獨(du)微(wei)調(diao)；0V電(dian)池(chi)(chi)恢復充(chong)電(dian)；32字(zi)節(jie)可加鎖EEPROM，16字(zi)節(jie)SRAM，64位(wei)ROM；

1-Wire，多節點，數字(zi)通(tong)信接口；支(zhi)持多電(dian)池組電(dian)源(yuan)(yuan)(yuan)管理(li)，并通(tong)過保護FET實(shi)現(xian)系統電(dian)源(yuan)(yuan)(yuan)控制；休眠模式(shi)下(xia)(xia)電(dian)源(yuan)(yuan)(yuan)電(dian)流僅2?A(最大);工作模式(shi)下(xia)(xia)電(dian)源(yuan)(yuan)(yuan)電(dian)流為90?A(最大);2.46mm×2.74mm倒裝片封裝或16引腳下(xia)(xia)SSOP封裝，兩者均可選擇帶(dai)或不帶(dai)檢測(ce)電(dian)阻;復具有(you)備有(you)評(ping)估板(ban).

4、結論

應用好(hao)便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子設備的(de)電(dian)(dian)(dian)(dian)池技術是(shi)選擇(ze)鋰(li)離子電(dian)(dian)(dian)(dian)池和鋰(li)聚合(he)物電(dian)(dian)(dian)(dian)池及其充(chong)電(dian)(dian)(dian)(dian)器的(de)基礎(chu).之于(yu)如何正確(que)選擇(ze),還必須視(shi)便(bian)攜(xie)式(shi)電(dian)(dian)(dian)(dian)子備的(de)具體要求(qiu)而定。