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)件(jian)用于由USB供電(dian)(dian)(dian)的(de)便攜式設(she)備(bei)，如媒體播(bo)放器(qi)、數(shu)碼相(xiang)機、PDA、個人導航(hang)器(qi)和(he)智能電(dian)(dian)(dian)話。LTC4098的(de)開關拓撲具有(you)電(dian)(dian)(dian)源(yuan)通路(PowerPath)控制(zhi)，可無縫(feng)地管(guan)理交(jiao)流適(shi)配器(qi)或USB端(duan)口和(he)設(she)備(bei)的(de)鋰(li)離子/聚合物(wu)電(dian)(dian)(dian)池之間的(de)電(dian)(dian)(dian)源(yuan)流動(dong)，同時優先向系統(tong)負(fu)載供電(dian)(dian)(dian)。就汽車、Firewire或其它高(gao)壓(ya)應(ying)用而言，LTC4098對凌力(li)爾特公司高(gao)達38V工作輸入(60V 瞬態(tai))的(de)伴隨(sui)開關穩壓(ya)器(qi)提供電(dian)(dian)(dian)池跟蹤(Bat-Track)控制(zhi)，從而最大限(xian)(xian)度(du)地提高(gao)了電(dian)(dian)(dian)池充(chong)電(dian)(dian)(dian)器(qi)的(de)效率、最大限(xian)(xian)度(du)地減少了熱量，并可以在USB和(he)較高(gao)壓(ya)電(dian)(dian)(dian)源(yuan)之間無縫(feng)轉換。

　　LTC4098僅需要一個(ge)外(wai)部NFET/電(dian)阻組合就(jiu)可在USB輸入提供高達66V的過(guo)壓(ya)保護(OVP)電(dian)路，以防止意外(wai)的高壓(ya)應用(yong)所引(yin)起的損壞。

　　LTC4098的“即時接通”工作確(que)保(bao)一(yi)(yi)插上(shang)電(dian)源就(jiu)向系(xi)統負載供(gong)電(dian)，甚至在電(dian)池(chi)沒電(dian)時也(ye)一(yi)(yi)樣(yang)。其內(nei)置的理想(xiang)二極管保(bao)證總(zong)是向VOUT提供(gong)充足(zu)的功率(lv)，即使LTC4098兩個輸入引腳功率(lv)不充足(zu)也(ye)一(yi)(yi)樣(yang)。該集成電(dian)路的理想(xiang)二極管控制器可用來驅動可選PFET的柵極，從而將對(dui)電(dian)池(chi)的阻抗降至30mΩ或更低。

　　LTC4098的全功能單節鋰離子/聚合物電池充電器允許負載電(dian)(dian)(dian)流(liu)(liu)(liu)超過從(cong)USB端(duan)口吸取(qu)的電(dian)(dian)(dian)流(liu)(liu)(liu)，同時符合USB負載規(gui)范。就快速充(chong)電(dian)(dian)(dian)而言，該集成(cheng)電(dian)(dian)(dian)路的開(kai)關(guan)輸入級幾乎將從(cong)USB端(duan)口獲(huo)得的所(suo)有(you)2.5W功率都轉換成(cheng)系統電(dian)(dian)(dian)流(liu)(liu)(liu)，從(cong)而用(yong)限(xian)制到500mA的USB端(duan)口實(shi)現(xian)了(le)高達(da)700mA的電(dian)(dian)(dian)流(liu)(liu)(liu)。用(yong)交(jiao)流(liu)(liu)(liu)適配器(qi)(qi)供電(dian)(dian)(dian)時，還有(you)1.5A充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)(liu)可(ke)用(yong)。另外，該充(chong)電(dian)(dian)(dian)器(qi)(qi)具有(you)熱量限(xian)制、可(ke)自動(dong)再充(chong)電(dian)(dian)(dian)、用(yong)自動(dong)充(chong)電(dian)(dian)(dian)終止和固(gu)定(ding)持(chi)續時間(jian)安全定(ding)時器(qi)(qi)實(shi)現(xian)獨立(li)工(gong)作、能以(yi)低壓涓流(liu)(liu)(liu)充(chong)電(dian)(dian)(dian)、可(ke)檢測壞電(dian)(dian)(dian)池(chi)并具有(you)一(yi)(yi)個熱敏電(dian)(dian)(dian)阻輸入以(yi)實(shi)現(xian)溫度合格的充(chong)電(dian)(dian)(dian)。該集成(cheng)電(dian)(dian)(dian)路的其它特(te)點包(bao)括：具有(you)一(yi)(yi)個暫(zan)停LDO以(yi)防止設(she)備連接到暫(zan)停USB端(duan)口時泄(xie)漏電(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)量。

　　LTC4098采用超(chao)薄(0.55mm)20引腳3mm x 4mm QFN封裝，保證(zheng)在(zai)-40℃至85℃的溫度(du)范圍內(nei)工(gong)作。以1,000片為(wei)單位批量購(gou)買(mai)，每片價(jia)格為(wei)2.50美(mei)元。

　　LTC4098性(xing)能概要：

　　具電(dian)(dian)池跟(gen)蹤(zong)自適應輸出控制的開關穩壓器充分利用USB端口(kou)提(ti)供的有限功率為(wei)電(dian)(dian)池充電(dian)(dian)以及為(wei)應用提(ti)供電(dian)(dian)源

　　過(guo)壓保護(高(gao)達66V)防止器件(jian)損(sun)壞

　　電池跟(gen)蹤外(wai)部(bu)降壓(ya)(ya)型開(kai)關穩(wen)壓(ya)(ya)器控制(zhi)在(zai)使用汽車、Firewire和其它高壓(ya)(ya)源(高達(da)38V連續電壓(ya)(ya)，60V瞬(shun)態)時最大限度提高效率(lv)

　　180mΩ內部(bu)理想二極管(guan)和外部(bu)理想二極管(guan)控制器在(zai)輸入(ru)功率(lv)受限(xian)或不提(ti)供(gong)時可(ke)無縫地提(ti)供(gong)低損(sun)耗電源通路

　　全功能鋰離子/聚合物電池充電器

　　從交流(liu)適配器提供1.5A最大充電(dian)電(dian)流(liu)，并具熱(re)量限制

　　從500mA USB端口向系統負載提供700mA最大電流(liu)

　　轉換控制降(jiang)低開關EMI

　　超薄(bo)(0.55mm) 20引(yin)線3mm x 4mm QFN封裝