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(qi)(qi)件用于由USB供(gong)(gong)電(dian)(dian)的便攜式設備，如媒體播(bo)放(fang)器(qi)(qi)、數(shu)碼(ma)相(xiang)機(ji)、PDA、個人導(dao)航器(qi)(qi)和(he)(he)智能電(dian)(dian)話。LTC4098的開關(guan)拓撲具有電(dian)(dian)源通路(PowerPath)控(kong)制，可(ke)無縫地(di)管理交流適配器(qi)(qi)或USB端(duan)口和(he)(he)設備的鋰離(li)子/聚合物電(dian)(dian)池(chi)之(zhi)間(jian)的電(dian)(dian)源流動，同時優先向(xiang)系統負(fu)載供(gong)(gong)電(dian)(dian)。就汽車、Firewire或其它高(gao)(gao)(gao)壓(ya)(ya)應用而(er)言(yan)，LTC4098對凌力爾(er)特(te)公司高(gao)(gao)(gao)達(da)38V工作(zuo)輸(shu)入(ru)(60V 瞬(shun)態)的伴(ban)隨開關(guan)穩(wen)壓(ya)(ya)器(qi)(qi)提供(gong)(gong)電(dian)(dian)池(chi)跟蹤(Bat-Track)控(kong)制，從而(er)最大限(xian)度地(di)提高(gao)(gao)(gao)了電(dian)(dian)池(chi)充電(dian)(dian)器(qi)(qi)的效率(lv)、最大限(xian)度地(di)減(jian)少(shao)了熱量，并(bing)可(ke)以在USB和(he)(he)較高(gao)(gao)(gao)壓(ya)(ya)電(dian)(dian)源之(zhi)間(jian)無縫轉換。

　　LTC4098僅(jin)需要(yao)一個外部NFET/電(dian)阻組(zu)合就可在USB輸入提(ti)供(gong)高達(da)66V的(de)(de)過壓(ya)保護(OVP)電(dian)路，以防止意外的(de)(de)高壓(ya)應用(yong)所引起的(de)(de)損壞。

　　LTC4098的(de)(de)“即(ji)時接通(tong)”工作確(que)保一插上電源就向系統負載供(gong)電，甚(shen)至(zhi)在電池(chi)沒電時也(ye)一樣。其內(nei)置(zhi)的(de)(de)理想二極(ji)管保證總是向VOUT提供(gong)充足(zu)的(de)(de)功率，即(ji)使(shi)LTC4098兩(liang)個輸入引腳功率不充足(zu)也(ye)一樣。該集成(cheng)電路的(de)(de)理想二極(ji)管控制器可用(yong)來(lai)驅動可選(xuan)PFET的(de)(de)柵極(ji)，從而將(jiang)對電池(chi)的(de)(de)阻(zu)抗降至(zhi)30mΩ或更低。

　　LTC4098的全功能單節鋰離子/聚合物電池充電器允許(xu)負載電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)超(chao)過從(cong)USB端口(kou)吸取的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，同時符合(he)USB負載規范。就快速充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)而言，該(gai)集(ji)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)路的(de)(de)開關輸入(ru)級幾乎將從(cong)USB端口(kou)獲(huo)得的(de)(de)所有(you)(you)2.5W功(gong)率都轉換成(cheng)系統電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，從(cong)而用(yong)限制到500mA的(de)(de)USB端口(kou)實(shi)現(xian)了高(gao)達700mA的(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)。用(yong)交流(liu)(liu)適(shi)配器供電(dian)(dian)(dian)(dian)(dian)(dian)時，還有(you)(you)1.5A充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)可(ke)用(yong)。另外(wai)，該(gai)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)器具有(you)(you)熱(re)量(liang)限制、可(ke)自動(dong)再充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)、用(yong)自動(dong)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)終止和固定(ding)持續(xu)時間(jian)安全定(ding)時器實(shi)現(xian)獨立(li)工作、能以(yi)(yi)低壓涓流(liu)(liu)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)、可(ke)檢測壞電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)并(bing)具有(you)(you)一(yi)個熱(re)敏電(dian)(dian)(dian)(dian)(dian)(dian)阻(zu)輸入(ru)以(yi)(yi)實(shi)現(xian)溫度(du)合(he)格的(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)。該(gai)集(ji)成(cheng)電(dian)(dian)(dian)(dian)(dian)(dian)路的(de)(de)其它特點包(bao)括：具有(you)(you)一(yi)個暫停LDO以(yi)(yi)防止設備(bei)連接到暫停USB端口(kou)時泄漏電(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)量(liang)。

　　LTC4098采(cai)用(yong)超薄(0.55mm)20引腳3mm x 4mm QFN封裝，保(bao)證在(zai)-40℃至(zhi)85℃的溫度范圍內工作(zuo)。以1,000片為(wei)單位(wei)批(pi)量購買，每片價格為(wei)2.50美元(yuan)。

　　LTC4098性能概要(yao)：

　　具電(dian)池跟蹤自(zi)適(shi)應(ying)輸出(chu)控制的開關穩壓(ya)器充分利用USB端口提(ti)供的有限功(gong)率為電(dian)池充電(dian)以及為應(ying)用提(ti)供電(dian)源

　　過壓(ya)保護(高達66V)防止器(qi)件損(sun)壞

　　電(dian)池跟蹤外部降壓(ya)型開關穩壓(ya)器控制在使用汽(qi)車(che)、Firewire和(he)其它高壓(ya)源(高達38V連續(xu)電(dian)壓(ya)，60V瞬(shun)態)時最大限度提(ti)高效率

　　180mΩ內部理想二(er)極管(guan)和外(wai)部理想二(er)極管(guan)控制器(qi)在輸入(ru)功率(lv)受限或不提供(gong)時可無縫地提供(gong)低損耗電(dian)源通路

　　全功能鋰離子/聚合物電池充電器

　　從交流(liu)適(shi)配器提供1.5A最(zui)大充電電流(liu)，并具熱(re)量(liang)限制

　　從500mA USB端口向系統負載提供700mA最大電流

　　轉換(huan)控制(zhi)降(jiang)低開(kai)關(guan)EMI

　　超薄(0.55mm) 20引線3mm x 4mm QFN封裝(zhuang)