自主式高效率電源管理器、理想二極管控制器和電池充電器LTC4098 該器件用于由USB供(gong)電的(de)(de)便(bian)攜式設備(bei)，如媒體播放器、數碼相(xiang)機、PDA、個人導航器和智能(neng)電話。LTC4098的(de)(de)開關(guan)拓(tuo)撲具有電源通路(PowerPath)控(kong)制(zhi)，可無縫地管理交流適(shi)配器或USB端(duan)口和設備(bei)的(de)(de)鋰(li)離子/聚合物電池(chi)之間的(de)(de)電源流動，同時優先向系統負載供(gong)電。就汽車、Firewire或其它(ta)高壓(ya)應用而言，LTC4098對凌力爾特(te)公司高達38V工作輸入(ru)(60V 瞬態)的(de)(de)伴隨開關(guan)穩壓(ya)器提(ti)(ti)供(gong)電池(chi)跟蹤(Bat-Track)控(kong)制(zhi)，從(cong)而最大(da)限度地提(ti)(ti)高了(le)(le)電池(chi)充(chong)電器的(de)(de)效率、最大(da)限度地減少了(le)(le)熱量，并可以在USB和較(jiao)高壓(ya)電源之間無縫轉換。

　　LTC4098僅需要一個外(wai)部NFET/電阻組合就可在(zai)USB輸入提供高達(da)66V的(de)(de)(de)過(guo)壓保護(hu)(OVP)電路，以(yi)防(fang)止意外(wai)的(de)(de)(de)高壓應用所(suo)引起的(de)(de)(de)損壞(huai)。

　　LTC4098的(de)(de)“即時接通(tong)”工作(zuo)確(que)保(bao)一插上電源(yuan)就向(xiang)系統負載供(gong)電，甚至在電池(chi)沒電時也一樣(yang)。其(qi)內置的(de)(de)理想(xiang)二極管(guan)保(bao)證總是(shi)向(xiang)VOUT提供(gong)充足(zu)的(de)(de)功率，即使LTC4098兩個輸入引腳功率不充足(zu)也一樣(yang)。該(gai)集成電路的(de)(de)理想(xiang)二極管(guan)控制(zhi)器可(ke)用來(lai)驅動(dong)可(ke)選PFET的(de)(de)柵極，從(cong)而將對電池(chi)的(de)(de)阻抗降至30mΩ或更低(di)。

　　LTC4098的全功能單節鋰離子/聚合物電池充電器允(yun)許負載電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)超過從(cong)(cong)USB端口(kou)吸取(qu)的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，同時(shi)符合USB負載規范。就快速(su)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)而言，該集成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)(de)開(kai)關輸(shu)入級(ji)幾乎將(jiang)從(cong)(cong)USB端口(kou)獲得的(de)(de)所有(you)2.5W功率都(dou)轉換成(cheng)系統電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)，從(cong)(cong)而用(yong)(yong)限制(zhi)(zhi)到(dao)500mA的(de)(de)USB端口(kou)實(shi)現了高達700mA的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)。用(yong)(yong)交流(liu)適(shi)配器(qi)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)，還有(you)1.5A充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)可(ke)用(yong)(yong)。另外(wai)，該充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器(qi)具(ju)有(you)熱量限制(zhi)(zhi)、可(ke)自動(dong)(dong)再(zai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)、用(yong)(yong)自動(dong)(dong)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)終止(zhi)和固定持(chi)續(xu)時(shi)間安全定時(shi)器(qi)實(shi)現獨立工作、能以(yi)(yi)低壓涓流(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)、可(ke)檢測(ce)壞(huai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)并具(ju)有(you)一個(ge)(ge)熱敏電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)阻輸(shu)入以(yi)(yi)實(shi)現溫度(du)合格的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。該集成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路的(de)(de)其它(ta)特(te)點包括：具(ju)有(you)一個(ge)(ge)暫(zan)停LDO以(yi)(yi)防止(zhi)設備連(lian)接到(dao)暫(zan)停USB端口(kou)時(shi)泄漏電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)量。

　　LTC4098采(cai)用超薄(0.55mm)20引腳3mm x 4mm QFN封裝，保證在(zai)-40℃至85℃的溫度范圍(wei)內工(gong)作。以1,000片(pian)為單位批(pi)量購買，每片(pian)價格為2.50美(mei)元。

　　LTC4098性(xing)能概要：

　　具電(dian)池(chi)跟(gen)蹤(zong)自(zi)適(shi)應(ying)輸出控制的開(kai)關穩壓器充(chong)分(fen)利用(yong)USB端口(kou)提供的有限功率為電(dian)池(chi)充(chong)電(dian)以及為應(ying)用(yong)提供電(dian)源

　　過壓保護(高達66V)防止器(qi)件損壞(huai)

　　電(dian)(dian)池跟蹤外(wai)部降壓(ya)型(xing)開關穩(wen)壓(ya)器控制在(zai)使(shi)用汽車(che)、Firewire和其它高(gao)壓(ya)源(高(gao)達38V連續電(dian)(dian)壓(ya)，60V瞬態)時最(zui)大限(xian)度提(ti)高(gao)效率(lv)

　　180mΩ內部理(li)想二極管(guan)和(he)外部理(li)想二極管(guan)控制器在輸(shu)入功率(lv)受(shou)限(xian)或不提供時可無縫地提供低(di)損耗電源通路

　　全功能鋰離子/聚合物電池充電器

　　從(cong)交流適配(pei)器提供1.5A最(zui)大充電電流，并具(ju)熱量限制

　　從500mA USB端口向系統負載提供700mA最大電流

　　轉(zhuan)換控制(zhi)降低開關EMI

　　超(chao)薄(0.55mm) 20引線3mm x 4mm QFN封裝