隨著對(dui)高效，輕便，快(kuai)速充(chong)電(dian)，安全且經(jing)濟(ji)高效的(de)便攜式電(dian)源需(xu)求的(de)日(ri)益增(zeng)加(jia)，市場上對(dui)鎳氫(qing)電(dian)池NIMH，可充(chong)電(dian)堿性(xing)鋰電(dian)池和鋰聚合物電(dian)池（Li-poly)已經(jing)都(dou)開發出來。為(wei)了(le)最大限度地提(ti)高性(xing)能并確保安全，市場上還開發了(le)可以(yi)充(chong)電(dian)和保護這些(xie)電(dian)池的(de)相同級別的(de)先(xian)進半導(dao)體設備(bei)。今天我(wo)們來說說新電(dian)池技術(shu)那些(xie)事，例(li)如(ru)：Maxim Integrated，Linear Technology和Texas Instruments等半導(dao)體供應商(shang)的(de)鋰離子電(dian)池新充(chong)電(dian)解決方案。

電池技術

在便(bian)攜式電(dian)子產(chan)品(pin)領域，一(yi)些新(xin)的(de)可充電(dian)電(dian)池化學品(pin)正在出現，將與最受青睞的(de)鎳鎘電(dian)池（NiCd）技術競爭。鎳鎘電(dian)池（NiCd）技術仍然適用(yong)于需要(yao)短期高電(dian)流且低(di)阻抗(kang)特性適用(yong)的(de)電(dian)動工具等應用(yong)。

然而，智能手機，平(ping)板電(dian)(dian)(dian)腦和數(shu)碼相機等新型便攜式應(ying)用的設計者正(zheng)在尋找比鎳(nie)鎘電(dian)(dian)(dian)池(chi)（NiCd)更高容量(liang)和更低放(fang)電(dian)(dian)(dian)率的電(dian)(dian)(dian)池(chi)。此外(wai)，這些應(ying)用需(xu)要快速充電(dian)(dian)(dian)，重量(liang)輕的電(dian)(dian)(dian)池(chi)。滿足此要求的電(dian)(dian)(dian)池(chi)技術包括鎳(nie)氫電(dian)(dian)(dian)池(chi)（NiMH),鋰離子電(dian)(dian)(dian)池(chi)(li-ion)和鋰聚(ju)合(he)物(wu)電(dian)(dian)(dian)池(chi)(Li-poly)。鎳(nie)氫電(dian)(dian)(dian)池(chi)（NiMH）具有高容量(liang)和快速充電(dian)(dian)(dian)的能力，但缺點是(shi)具有相對較高的放(fang)電(dian)(dian)(dian)速率，是(shi)鎳(nie)鎘電(dian)(dian)(dian)池(chi)（NiCd）的兩(liang)倍（表1）。

表1：化學成分類型的主電池參數

鋰(li)(li)-聚合物(wu)表現出更高的容(rong)量(liang)和比鎳鎘電池(chi)和鎳氫電池(chi)一個(ge)顯著較低放電率。此外，根據應用說明，鋰(li)(li)離(li)(li)子(zi)電池(chi)重(zhong)量(liang)更輕。結(jie)果，估計鋰(li)(li)離(li)(li)子(zi)電池(chi)每單位質量(liang)的鎳氫電池(chi)（NiMH）容(rong)量(liang)幾乎是(shi)其兩倍。

然而(er)，鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)也(ye)有幾個問(wen)題需要注(zhu)意。Maxim指出，鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)對(dui)過(guo)度充(chong)電(dian)(dian)(dian)(dian)和(he)充(chong)電(dian)(dian)(dian)(dian)不足(zu)非常(chang)敏感。過(guo)高的(de)電(dian)(dian)(dian)(dian)壓會(hui)對(dui)電(dian)(dian)(dian)(dian)池(chi)造(zao)成永久性損壞，但由于(yu)嚴(yan)重的(de)欠(qian)電(dian)(dian)(dian)(dian)壓而(er)反(fan)復放(fang)電(dian)(dian)(dian)(dian)會(hui)導致(zhi)容量損失。因(yin)此，為了保護(hu)電(dian)(dian)(dian)(dian)池(chi)，充(chong)電(dian)(dian)(dian)(dian)解決方案必須限(xian)制電(dian)(dian)(dian)(dian)池(chi)的(de)電(dian)(dian)(dian)(dian)流和(he)電(dian)(dian)(dian)(dian)壓以(yi)及放(fang)電(dian)(dian)(dian)(dian)時的(de)電(dian)(dian)(dian)(dian)荷。

因(yin)此，鋰(li)離子電(dian)池組通常包括(kuo)用于保護任(ren)何(he)形式的欠壓和過(guo)壓的電(dian)路，以及防止暴露于過(guo)電(dian)流的保險(xian)絲。根據(ju)Maxim的說法，這(zhe)些電(dian)池組還包括(kuo)一個開關，可(ke)在高壓引氣時打開電(dian)池。

此外，鋰(li)離子電(dian)(dian)(dian)(dian)池(chi)必(bi)須使用電(dian)(dian)(dian)(dian)流(liu)和(he)電(dian)(dian)(dian)(dian)壓(ya)源(yuan)的(de)(de)(de)組合(he)進行(xing)充電(dian)(dian)(dian)(dian)，這(zhe)與鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)（NiCd）和(he)鎳(nie)氫電(dian)(dian)(dian)(dian)池(chi)（NiMH）不(bu)(bu)同(tong)，鎳(nie)鎘電(dian)(dian)(dian)(dian)池(chi)（NiCd）和(he)鎳(nie)氫電(dian)(dian)(dian)(dian)池(chi)（NiMH）在充電(dian)(dian)(dian)(dian)時需(xu)要電(dian)(dian)(dian)(dian)流(liu)源(yuan)。為了在不(bu)(bu)損壞(huai)的(de)(de)(de)情況下(xia)最大(da)(da)化(hua)充電(dian)(dian)(dian)(dian)，大(da)(da)多(duo)數鋰(li)離子充電(dian)(dian)(dian)(dian)器在輸出電(dian)(dian)(dian)(dian)壓(ya)的(de)(de)(de)1％范圍內保持誤差。通(tong)常不(bu)(bu)推薦較低的(de)(de)(de)公差，因為它(ta)們難以維(wei)護并增加成本(ben)。通(tong)常，容量的(de)(de)(de)好處少于這(zhe)些努力。

單節鋰離子充電器

為移動電(dian)(dian)(dian)話和(he)其他(ta)類似(si)設備(bei)充(chong)(chong)電(dian)(dian)(dian)的(de)(de)首選(xuan)方法是(shi)(shi)(shi)使用(yong)一個稱為“支架(jia)充(chong)(chong)電(dian)(dian)(dian)器”的(de)(de)獨立設備(bei)來(lai)放置設備(bei)或(huo)電(dian)(dian)(dian)池組(zu)。根(gen)據Maxim的(de)(de)說(shuo)法，單節鋰離子或(huo)鋰聚合物(wu)充(chong)(chong)電(dian)(dian)(dian)器適(shi)合與搖籃一起使用(yong)。由于(yu)(yu)電(dian)(dian)(dian)池組(zu)或(huo)充(chong)(chong)電(dian)(dian)(dian)器單元是(shi)(shi)(shi)分開的(de)(de)，因(yin)此產生(sheng)的(de)(de)熱量不(bu)是(shi)(shi)(shi)問(wen)題(ti)，因(yin)為它沒有集成到設備(bei)中。在這種情況下，線性調節器使直(zhi)流電(dian)(dian)(dian)源和(he)電(dian)(dian)(dian)池之間的(de)(de)電(dian)(dian)(dian)壓差在線性范(fan)圍內通(tong)過(guo)傳輸晶(jing)體管。由于(yu)(yu)充(chong)(chong)電(dian)(dian)(dian)器用(yong)于(yu)(yu)較(jiao)小的(de)(de)空間，建(jian)議通(tong)風以防止因(yin)功耗而導致過(guo)熱。

Maxim的(de)線性單節鋰(li)(li)離子充(chong)電(dian)(dian)(dian)器采用MAX846A它(ta)被指定(ding)(ding)為(wei)。0.5％的(de)參(can)考(kao)精度可安全地對需(xu)要高電(dian)(dian)(dian)壓(ya)(ya)(ya)精度的(de)鋰(li)(li)離子電(dian)(dian)(dian)池(chi)充(chong)電(dian)(dian)(dian)。控制(zhi)低成本外(wai)部PNP晶體管（或P溝道(dao)MOSFET）的(de)電(dian)(dian)(dian)壓(ya)(ya)(ya)和電(dian)(dian)(dian)流調節環(huan)路彼(bi)此獨立工作。如圖1所示，飛兆半導體的(de)外(wai)部功(gong)率(lv)晶體管FZT749將電(dian)(dian)(dian)源電(dian)(dian)(dian)壓(ya)(ya)(ya)降(jiang)至電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)，并調節電(dian)(dian)(dian)路的(de)大部分(fen)功(gong)耗。因此，內部參(can)考(kao)更(geng)穩(wen)定(ding)(ding)，并提(ti)供更(geng)穩(wen)定(ding)(ding)的(de)電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)壓(ya)(ya)(ya)限(xian)制(zhi)。

圖1：線性(xing)單節鋰離子充(chong)電(dian)器MAX846A驅動(dong)外(wai)部(bu)功率晶(jing)體管(guan)（Q1），將電(dian)源電(dian)壓(ya)降至電(dian)池(chi)電(dian)壓(ya)。

在該電(dian)(dian)(dian)(dian)路中，R1和(he)R3決(jue)定(ding)輸(shu)(shu)出電(dian)(dian)(dian)(dian)流。R1檢測充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流，R3確(que)定(ding)電(dian)(dian)(dian)(dian)流調節的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)平。ISET端子(zi)的(de)(de)(de)(de)輸(shu)(shu)出電(dian)(dian)(dian)(dian)流等于CS +和(he)CS-之間電(dian)(dian)(dian)(dian)壓(ya)(ya)的(de)(de)(de)(de)1/1000。電(dian)(dian)(dian)(dian)流調節器將(jiang)ISET電(dian)(dian)(dian)(dian)壓(ya)(ya)控制(zhi)在2V。結果，電(dian)(dian)(dian)(dian)流限(xian)制(zhi)[2,000 /（R3 * R1）]為(wei)1A。如Maxim應用筆記所(suo)述，電(dian)(dian)(dian)(dian)壓(ya)(ya)和(he)電(dian)(dian)(dian)(dian)流限(xian)制(zhi)的(de)(de)(de)(de)控制(zhi)回路具有(you)單獨的(de)(de)(de)(de)補償點(dian)（CCV和(he)CCI），以(yi)(yi)簡化穩定(ding)這些限(xian)制(zhi)的(de)(de)(de)(de)任務。可以(yi)(yi)使用ISET和(he)VSET端子(zi)調整電(dian)(dian)(dian)(dian)流和(he)電(dian)(dian)(dian)(dian)壓(ya)(ya)限(xian)制(zhi)。

德州儀(yi)器(qi)還為空(kong)間受(shou)限的便攜式應用提供(gong)線性充(chong)(chong)電(dian)器(qi)。TI高度(du)集成的bq24040系列是用于單節(jie)鋰離(li)子和鋰聚(ju)合物電(dian)池的充(chong)(chong)電(dian)器(qi)IC。該充(chong)(chong)電(dian)器(qi)可以處理高輸(shu)入電(dian)壓范圍，可以通過USB端(duan)口或低成本AC適配器(qi)驅(qu)動。據TI稱，bq2404x器(qi)件分三個階段為電(dian)池充(chong)(chong)電(dian)：管理 – 恒(heng)定電(dian)流(liu)(liu) – 恒(heng)定電(dian)壓。在所(suo)有充(chong)(chong)電(dian)階段，內(nei)部(bu)控(kong)制環(huan)路監控(kong)IC結溫(wen)度(du)，并在內(nei)部(bu)溫(wen)度(du)超過一定水平(ping)時降低充(chong)(chong)電(dian)電(dian)流(liu)(liu)。

同樣，凌力爾特公司的(de)(de)(de)獨立(li)鋰離(li)子(zi)電(dian)(dian)池LTM8061針對單(dan)電(dian)(dian)池和(he)雙(shuang)電(dian)(dian)池鋰離(li)子(zi)和(he)鋰聚合物封(feng)裝(zhuang)進行了(le)優化，具有(you)4.1V，4.2V，8.2V和(he)8.4V的(de)(de)(de)固定浮動(dong)電(dian)(dian)壓選(xuan)項。充(chong)(chong)電(dian)(dian)器(qi)提供恒定電(dian)(dian)流和(he)恒定電(dian)(dian)壓充(chong)(chong)電(dian)(dian)特性(xing)，可以充(chong)(chong)電(dian)(dian)至2A。微型模塊（微型組件）在(zai)電(dian)(dian)池充(chong)(chong)電(dian)(dian)器(qi)的(de)(de)(de)規范集成的(de)(de)(de)DC和(he)DC控制器(qi)，功(gong)率晶體管，以及輸入和(he)輸出電(dian)(dian)容(rong)，所述補(bu)償部(bu)分，即(ji)完整的(de)(de)(de)包系統（SIP）填充(chong)(chong)溶液，其包含具有(you)小(xiao)LGA封(feng)裝(zhuang)的(de)(de)(de)電(dian)(dian)感器(qi)安裝(zhuang)在(zai)表(biao)面上它代表(biao)。因此，基于LTM8061的(de)(de)(de)單(dan)節(jie)鋰離(li)子(zi)充(chong)(chong)電(dian)(dian)器(qi)使用最(zui)少的(de)(de)(de)外(wai)部(bu)元件（圖2）。

圖2：μModule電池充電器LTM8061是一款用于單節鋰離子電池的全封裝(zhuang)系(xi)統（SiP）充電解決方案。

其他為(wei)單節(jie)鋰(li)離子和(he)鋰(li)聚(ju)合物(wu)封裝提供集成(cheng)充電器IC的供應商(shang)包括飛(fei)兆半(ban)導體，Intersil和(he)意法半(ban)導體。

為兩個或更多電池充電

圖3顯示了為兩個連接的鋰離子電池充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)類(lei)似電(dian)(dian)(dian)(dian)(dian)路。該電(dian)(dian)(dian)(dian)(dian)路采用(yong)(yong)Maxim MAX745，一種開關鋰離子電(dian)(dian)(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)(dian)(dian)器，可提(ti)(ti)供(gong)90％的(de)(de)(de)(de)效率(lv)。MAX745集(ji)成在(zai)所有(you)必要的(de)(de)(de)(de)用(yong)(yong)于鋰離子電(dian)(dian)(dian)(dian)(dian)池組(zu)的(de)(de)(de)(de)功能的(de)(de)(de)(de)沒有(you)被熱充(chong)電(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)芯片(pian)，提(ti)(ti)供(gong)高達(da)4A的(de)(de)(de)(de)受控(kong)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流，并提(ti)(ti)供(gong)調(diao)節的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)壓，在(zai)電(dian)(dian)(dian)(dian)(dian)池端子僅具有(you)的(de)(de)(de)(de)±0.75％的(de)(de)(de)(de)總誤差。MAX745采用(yong)(yong)廉(lian)價的(de)(de)(de)(de)1％電(dian)(dian)(dian)(dian)(dian)阻設置輸(shu)出電(dian)(dian)(dian)(dian)(dian)壓，并使用(yong)(yong)低成本N溝(gou)道MOSFET作為電(dian)(dian)(dian)(dian)(dian)源開關。電(dian)(dian)(dian)(dian)(dian)壓漂移(yi)和(he)充(chong)電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流通過兩個環路調(diao)節，可在(zai)電(dian)(dian)(dian)(dian)(dian)壓和(he)電(dian)(dian)(dian)(dian)(dian)流調(diao)節之間平滑(hua)切換。根據標準(zhun)的(de)(de)(de)(de)1％電(dian)(dian)(dian)(dian)(dian)阻，每個電(dian)(dian)(dian)(dian)(dian)池的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)池電(dian)(dian)(dian)(dian)(dian)壓調(diao)節限制(zhi)設置在(zai)4V和(he)4.4V之間。

圖(tu)3：MAX745是一(yi)款全(quan)功能開關充(chong)電器，用于為多個連接的(de)鋰離子電池充(chong)電。

德州儀器（TI）和凌(ling)力爾特公司(si)（Linear Technology）等廠(chang)商(shang)也(ye)提供為兩個連接(jie)的(de)鋰(li)離(li)子電(dian)(dian)池充電(dian)(dian)的(de)集成IC。選擇(ze)一個電(dian)(dian)池充電(dian)(dian)器IC的(de)應用，充電(dian)(dian)電(dian)(dian)流，充電(dian)(dian)技術(shu)，保護功能，USB兼容，成本之(zhi)前，多個電(dian)(dian)池鋰(li)離(li)子電(dian)(dian)池，設計師(shi)輸入電(dian)(dian)壓充電(dian)(dian)，并且像其他關(guan)鍵點您必須先查看要(yao)求。