USB電源管理器和鋰離子電池充電器LTC4098
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(yong)于(yu)由USB供電(dian)(dian)的(de)(de)便攜式(shi)設備(bei),如媒體播放器(qi)、數(shu)碼相機(ji)、PDA、個人(ren)導航器(qi)和(he)智能電(dian)(dian)話。LTC4098的(de)(de)開關拓撲具(ju)有(you)電(dian)(dian)源(yuan)(yuan)(yuan)通路(PowerPath)控制,可無(wu)縫地(di)管理交(jiao)流適配器(qi)或USB端口和(he)設備(bei)的(de)(de)鋰離子/聚合(he)物電(dian)(dian)池(chi)(chi)之間的(de)(de)電(dian)(dian)源(yuan)(yuan)(yuan)流動,同時優(you)先向系統負(fu)載(zai)供電(dian)(dian)。就汽車、Firewire或其它高(gao)壓(ya)應用(yong)而(er)言,LTC4098對凌力爾特(te)公司高(gao)達38V工作(zuo)輸(shu)入(ru)(60V 瞬態)的(de)(de)伴隨開關穩壓(ya)器(qi)提供電(dian)(dian)池(chi)(chi)跟(gen)蹤(Bat-Track)控制,從而(er)最大限度地(di)提高(gao)了電(dian)(dian)池(chi)(chi)充電(dian)(dian)器(qi)的(de)(de)效率、最大限度地(di)減少了熱量,并可以在USB和(he)較(jiao)高(gao)壓(ya)電(dian)(dian)源(yuan)(yuan)(yuan)之間無(wu)縫轉換(huan)。
LTC4098僅需要一個(ge)外部(bu)NFET/電阻組(zu)合就可在USB輸(shu)入(ru)提供高(gao)達66V的(de)過(guo)壓保護(hu)(OVP)電路,以防止意外的(de)高(gao)壓應用所引(yin)起的(de)損壞。
LTC4098的(de)(de)“即(ji)時(shi)接通”工作確保一插上電源就向系統負載供電,甚至在電池沒電時(shi)也一樣。其內置的(de)(de)理(li)想二極(ji)管保證(zheng)總是向VOUT提供充足的(de)(de)功(gong)率,即(ji)使LTC4098兩個輸入(ru)引腳功(gong)率不充足也一樣。該集成電路的(de)(de)理(li)想二極(ji)管控制(zhi)器可用來(lai)驅動可選PFET的(de)(de)柵(zha)極(ji),從而將對電池的(de)(de)阻抗(kang)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)流(liu)(liu)超過從(cong)USB端(duan)口(kou)(kou)吸取的電(dian)(dian)(dian)流(liu)(liu),同時(shi)符合(he)USB負載規范。就(jiu)快(kuai)速(su)充(chong)電(dian)(dian)(dian)而言,該集成(cheng)電(dian)(dian)(dian)路的開關輸(shu)入(ru)級幾乎將從(cong)USB端(duan)口(kou)(kou)獲(huo)得(de)的所(suo)有2.5W功率(lv)都轉換成(cheng)系統電(dian)(dian)(dian)流(liu)(liu),從(cong)而用(yong)限制到(dao)500mA的USB端(duan)口(kou)(kou)實(shi)現了(le)高達(da)700mA的電(dian)(dian)(dian)流(liu)(liu)。用(yong)交(jiao)流(liu)(liu)適配器(qi)供電(dian)(dian)(dian)時(shi),還有1.5A充(chong)電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)(liu)可用(yong)。另外,該充(chong)電(dian)(dian)(dian)器(qi)具(ju)有熱量限制、可自(zi)動再充(chong)電(dian)(dian)(dian)、用(yong)自(zi)動充(chong)電(dian)(dian)(dian)終止和固定持續時(shi)間安全定時(shi)器(qi)實(shi)現獨(du)立(li)工作、能以低壓涓流(liu)(liu)充(chong)電(dian)(dian)(dian)、可檢測壞電(dian)(dian)(dian)池并(bing)具(ju)有一個熱敏電(dian)(dian)(dian)阻輸(shu)入(ru)以實(shi)現溫度合(he)格的充(chong)電(dian)(dian)(dian)。該集成(cheng)電(dian)(dian)(dian)路的其它特點包括:具(ju)有一個暫停LDO以防(fang)止設備連接(jie)到(dao)暫停USB端(duan)口(kou)(kou)時(shi)泄(xie)漏電(dian)(dian)(dian)池電(dian)(dian)(dian)量。
LTC4098采(cai)用超薄(bo)(0.55mm)20引腳3mm x 4mm QFN封裝,保證在-40℃至85℃的溫度范圍內(nei)工作。以(yi)1,000片為單(dan)位批量購(gou)買,每片價格(ge)為2.50美元。
LTC4098性能(neng)概要:
具(ju)電池跟蹤(zong)自適應輸出控制的開關穩壓器充分利用(yong)USB端口提(ti)供(gong)的有限功(gong)率為電池充電以及(ji)為應用(yong)提(ti)供(gong)電源(yuan)
過壓保護(高達66V)防止器件損壞
電池跟蹤外部(bu)降壓(ya)(ya)(ya)型(xing)開關穩(wen)壓(ya)(ya)(ya)器控制在使用汽車、Firewire和其它高(gao)壓(ya)(ya)(ya)源(yuan)(高(gao)達(da)38V連(lian)續電壓(ya)(ya)(ya),60V瞬態)時最(zui)大限度(du)提高(gao)效(xiao)率
180mΩ內部(bu)理想(xiang)二(er)極(ji)管和外(wai)部(bu)理想(xiang)二(er)極(ji)管控制(zhi)器在(zai)輸(shu)入(ru)功率(lv)受限(xian)或不提(ti)(ti)供時可無(wu)縫地提(ti)(ti)供低損耗電(dian)源通路
全功能鋰離子/聚合物電池充電器
從交流適配器提供1.5A最大充(chong)電電流,并具熱量限制
從500mA USB端口向系統負載提供(gong)700mA最(zui)大電流
轉(zhuan)換(huan)控制降低(di)開關EMI
超薄(0.55mm) 20引線3mm x 4mm QFN封裝