便攜式(shi)電(dian)(dian)(dian)源的(de)(de)應用(yong)范(fan)圍很(hen)廣，也很(hen)多樣(yang)(yang)化。產品包括消耗uW級平均功率的(de)(de)無線傳感(gan)器節點以(yi)及可用(yong)小(xiao)車推(tui)著(zhu)的(de)(de)、電(dian)(dian)(dian)池(chi)(chi)組耗電(dian)(dian)(dian)數百瓦-時的(de)(de)醫療或數據(ju)采集系統。不(bu)(bu)過，盡管(guan)應用(yong)種類很(hen)多，仍然(ran)出現了(le)幾個趨勢，設計師日益需要(yao)(yao)給產品提供(gong)更大的(de)(de)功率，以(yi)支持不(bu)(bu)斷增多的(de)(de)功能，同時也在考慮怎樣(yang)(yang)用(yong)任何可用(yong)電(dian)(dian)(dian)源給電(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)。要(yao)(yao)滿足第一種需求(qiu)，就要(yao)(yao)提高(gao)電(dian)(dian)(dian)池(chi)(chi)容量(liang)(liang)。不(bu)(bu)幸的(de)(de)是，用(yong)戶大多比較心急，容量(liang)(liang)提高(gao)以(yi)后(hou)，還必須在一個合(he)理的(de)(de)時間內充滿電(dian)(dian)(dian)，這就導致要(yao)(yao)增大充電(dian)(dian)(dian)電(dian)(dian)(dian)流。要(yao)(yao)滿足第二種需求(qiu)，就要(yao)(yao)求(qiu)電(dian)(dian)(dian)池(chi)(chi)充電(dian)(dian)(dian)解決(jue)方案提供(gong)極大的(de)(de)靈活(huo)性。本文(wen)將更詳(xiang)細地討論這些問(wen)題。

　　更大的功率

　　考慮一下(xia)新式(shi)(shi)(shi)(shi)(shi)手持(chi)式(shi)(shi)(shi)(shi)(shi)設(she)(she)備(bei)，面向(xiang)消費者的(de)設(she)(she)備(bei)和(he)工業設(she)(she)備(bei)都可能包括蜂窩電(dian)(dian)(dian)話調制解調器、Wi-Fi模塊、藍牙模塊、大尺寸(cun)背光照明顯示屏…等等。很(hen)多(duo)(duo)手持(chi)式(shi)(shi)(shi)(shi)(shi)設(she)(she)備(bei)的(de)電(dian)(dian)(dian)源(yuan)(yuan)架(jia)構都與蜂窩電(dian)(dian)(dian)話的(de)非(fei)常相(xiang)似。一般情況下(xia)，用一個(ge)3.7V的(de)鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)池作(zuo)為(wei)主電(dian)(dian)(dian)源(yuan)(yuan)，因為(wei)鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)池按重量和(he)按體積的(de)能量密度都很(hen)高(gao)(單位分別為(wei)Wh/kg和(he)Wh/m3)。過(guo)去(qu)，很(hen)多(duo)(duo)大功率設(she)(she)備(bei)都采(cai)用7.4V鋰(li)離子(zi)(zi)(zi)電(dian)(dian)(dian)池，以降低(di)電(dian)(dian)(dian)流(liu)要求，不(bu)過(guo)低(di)價5V電(dian)(dian)(dian)源(yuan)(yuan)管理IC的(de)上市(shi)已(yi)經(jing)促(cu)使越來(lai)越多(duo)(duo)的(de)手持(chi)式(shi)(shi)(shi)(shi)(shi)設(she)(she)備(bei)采(cai)用了(le)電(dian)(dian)(dian)壓更低(di)的(de)架(jia)構。平板(ban)電(dian)(dian)(dian)腦很(hen)好地說(shuo)明了(le)這(zhe)一點(dian)：一個(ge)典(dian)型的(de)平板(ban)電(dian)(dian)(dian)腦有極多(duo)(duo)的(de)功能以及(ji)非(fei)常大的(de)顯示屏(就便攜式(shi)(shi)(shi)(shi)(shi)設(she)(she)備(bei)而言)。用3.7V電(dian)(dian)(dian)池供電(dian)(dian)(dian)時，其容(rong)量必須(xu)以數(shu)千(qian)毫安(an)-小時計算。為(wei)了(le)在幾個(ge)小時內(nei)給這(zhe)樣一個(ge)電(dian)(dian)(dian)池充滿電(dian)(dian)(dian)，需要數(shu)千(qian)mA的(de)充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)。

　　然而(er)，如果(guo)沒有大電(dian)(dian)流(liu)(liu)交流(liu)(liu)適(shi)配器(qi)(qi)，盡管充(chong)電(dian)(dian)電(dian)(dian)流(liu)(liu)這么高，也不能防止消費者用USB端(duan)(duan)口(kou)(kou)給(gei)大功(gong)(gong)率設備(bei)充(chong)電(dian)(dian)的(de)想法。為(wei)了滿足(zu)這種需(xu)求，當交流(liu)(liu)適(shi)配器(qi)(qi)可用時，電(dian)(dian)池(chi)充(chong)電(dian)(dian)器(qi)(qi)必(bi)(bi)須能以大電(dian)(dian)流(liu)(liu)(>2A)充(chong)電(dian)(dian)，而(er)在沒有交流(liu)(liu)適(shi)配器(qi)(qi)可用時，電(dian)(dian)池(chi)充(chong)電(dian)(dian)器(qi)(qi)必(bi)(bi)須仍能高效(xiao)地(di)利(li)用USB端(duan)(duan)口(kou)(kou)提供(gong)2.5W至4.5W功(gong)(gong)率。此外(wai)，器(qi)(qi)件(jian)必(bi)(bi)須保(bao)護(hu)敏(min)感的(de)下(xia)游(you)低壓組(zu)件(jian)免受可能出現過壓情況所導致(zhi)的(de)損壞，同時必(bi)(bi)須無(wu)縫地(di)將大電(dian)(dian)流(liu)(liu)從USB輸(shu)入(ru)、交流(liu)(liu)適(shi)配器(qi)(qi)或電(dian)(dian)池(chi)傳(chuan)送到負載，并最大限度地(di)降(jiang)低功(gong)(gong)耗(hao)。另(ling)外(wai)，該IC還(huan)必(bi)(bi)須安全地(di)管理電(dian)(dian)池(chi)充(chong)電(dian)(dian)算法，并監視關鍵的(de)系統參數。

　　戰(zhan)勝單節電(dian)池供電(dian)的便攜式產品在功率方面的挑(tiao)戰(zhan)

　　盡管看(kan)似不可(ke)(ke)能找到能滿足上述要求的(de)(de)(de)單個IC，不過看(kan)一(yi)(yi)(yi)下LTC4155，這是一(yi)(yi)(yi)個大(da)功(gong)率(lv)(lv)、I2C控(kong)制的(de)(de)(de)高效(xiao)率(lv)(lv)電(dian)(dian)(dian)(dian)源通路(lu)(PowerPath?)管理器(qi)(qi)、理想二極管控(kong)制器(qi)(qi)和(he)鋰離(li)子電(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)器(qi)(qi)。該(gai)IC用(yong)來從各種5V電(dian)(dian)(dian)(dian)源高效(xiao)地傳送(song)高達3A的(de)(de)(de)電(dian)(dian)(dian)(dian)流(liu)(liu)，可(ke)(ke)產生超(chao)過3.5A的(de)(de)(de)可(ke)(ke)用(yong)電(dian)(dian)(dian)(dian)流(liu)(liu)，以(yi)供(gong)電(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)和(he)系(xi)統使用(yong)(參(can)見圖1)。LTC4155的(de)(de)(de)效(xiao)率(lv)(lv)為88%至94%，因此即(ji)使電(dian)(dian)(dian)(dian)流(liu)(liu)值這么(me)大(da)，該(gai)IC仍然可(ke)(ke)以(yi)減輕熱量預算限制(參(can)見圖2)。LTC4155的(de)(de)(de)開(kai)關式(shi)電(dian)(dian)(dian)(dian)源通路(lu)拓撲無縫地管理從兩種輸入電(dian)(dian)(dian)(dian)源(例如一(yi)(yi)(yi)個交流(liu)(liu)適配(pei)器(qi)(qi)和(he)一(yi)(yi)(yi)個USB端口)到設(she)備(bei)中可(ke)(ke)再充電(dian)(dian)(dian)(dian)鋰離(li)子電(dian)(dian)(dian)(dian)池的(de)(de)(de)配(pei)電(dian)(dian)(dian)(dian)，同時當(dang)輸入功(gong)率(lv)(lv)有限時，優先(xian)為系(xi)統負載供(gong)電(dian)(dian)(dian)(dian)。

圖1：LTC4155的典型應用電路(lu)

圖(tu)2：LTC4155的典型效率(lv)

　　與典型的(de)線性模式充(chong)(chong)電(dian)器(qi)相比，LTC4155中開(kai)關穩(wen)壓器(qi)的(de)作用就像一(yi)個變(bian)壓器(qi)，允許VOUT上(shang)的(de)負(fu)載電(dian)流(liu)(liu)超(chao)過輸入電(dian)源吸取(qu)的(de)電(dian)流(liu)(liu)，并(bing)極大地(di)提高電(dian)池充(chong)(chong)電(dian)的(de)可用功率。前述例子說明了LTC4155怎樣才(cai)能以高達(da)3.5A的(de)電(dian)流(liu)(liu)高效(xiao)率地(di)充(chong)(chong)電(dian)，以實現更快的(de)充(chong)(chong)電(dian)時(shi)間。與普通的(de)開(kai)關型電(dian)池充(chong)(chong)電(dian)器(qi)不同，LTC4155可即時(shi)接通工作，以確保即使電(dian)池沒(mei)電(dian)或已深度放(fang)電(dian)，當一(yi)插(cha)上(shang)電(dian)源插(cha)頭(tou)，系(xi)統(tong)電(dian)源也(ye)立即可用。

　　盡管是(shi)以(yi)(yi)很高的(de)速率(lv)(lv)給電(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)，監視(shi)電(dian)(dian)(dian)(dian)池(chi)是(shi)否安(an)全也是(shi)很重要的(de)。當(dang)電(dian)(dian)(dian)(dian)池(chi)溫(wen)(wen)度(du)降(jiang)至低于(yu)0°C或升至高于(yu)40°C[由一個(ge)(ge)外部負溫(wen)(wen)度(du)系數(NTC)熱敏(min)電(dian)(dian)(dian)(dian)阻(zu)測量]時，LTC4155將自動停止充電(dian)(dian)(dian)(dian)。除了這種自主式功能(neng)，LTC4155還(huan)提供一個(ge)(ge)7位(wei)擴展標度(du)模數轉換(huan)器(ADC)，以(yi)(yi)大約1°C的(de)分辨(bian)率(lv)(lv)監視(shi)電(dian)(dian)(dian)(dian)池(chi)溫(wen)(wen)度(du)(參見圖3)。結合4個(ge)(ge)可(ke)用(yong)的(de)浮(fu)置(zhi)電(dian)(dian)(dian)(dian)壓設定(ding)值和(he)15個(ge)(ge)電(dian)(dian)(dian)(dian)池(chi)充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流設定(ding)值，該ADC可(ke)基于(yu)電(dian)(dian)(dian)(dian)池(chi)溫(wen)(wen)度(du)來(lai)建立定(ding)制的(de)充電(dian)(dian)(dian)(dian)算法。

圖3：7位(wei)熱(re)敏電阻器ADC顯(xian)示LTC4155的預置溫度跳變(bian)點(dian)

　　通過一個簡單的兩線I2C端口可獲得NTCADC的結果，從而能調節充電電流和電壓的設定值。該I2C端口通過控制16個輸入電流的設定值(包括USB2.0和3.0兼容設置)，還可提供USB兼容性。該通信總線允許LTC4155指示額外的狀態信息，例如輸入電源狀態、充電器狀態和故(gu)障狀態。由于支持USBOTG，因此無需(xu)任(ren)何(he)額外的組件，就可以反過(guo)來(lai)向USB端口(kou)提供5V電源。

　　LTC4155的(de)雙路(lu)(lu)輸(shu)入(ru)、優(you)先(xian)級(ji)(ji)(ji)多路(lu)(lu)復用器(qi)可根據用戶定義的(de)優(you)先(xian)級(ji)(ji)(ji)(默認的(de)優(you)先(xian)級(ji)(ji)(ji)為適(shi)(shi)配器(qi)輸(shu)入(ru))自主地選擇最(zui)合適(shi)(shi)的(de)輸(shu)入(ru)(即墻(qiang)上適(shi)(shi)配器(qi)或(huo)USB)。過(guo)壓保(bao)護(hu)(OVP)電路(lu)(lu)同時(shi)保(bao)護(hu)兩(liang)個輸(shu)入(ru)，以免這些(xie)輸(shu)入(ru)因無意(yi)間加上的(de)高壓或(huo)反(fan)向電壓而(er)損壞(huai)。LTC4155的(de)理想二極管控制(zhi)器(qi)保(bao)證即使輸(shu)入(ru)功(gong)(gong)(gong)率(lv)不足或(huo)未(wei)提供輸(shu)入(ru)功(gong)(gong)(gong)率(lv)時(shi)，也始終可向VOUT提供足夠的(de)功(gong)(gong)(gong)率(lv)。

　　就平板電(dian)(dian)(dian)腦、工業條(tiao)碼(ma)掃描器等(deng)很多便(bian)攜(xie)式應用(yong)(yong)而言(yan)，能管理兩(liang)個輸入(例如USB和交流(liu)適配器)就足(zu)夠了。不(bu)過，便(bian)攜(xie)式設(she)備的設(she)計(ji)師一(yi)直(zhi)在尋求(qiu)用(yong)(yong)任(ren)何可用(yong)(yong)電(dian)(dian)(dian)源都能給電(dian)(dian)(dian)池充電(dian)(dian)(dian)的方法

　　多種輸入源

　　用(yong)(yong)戶要(yao)(yao)用(yong)(yong)多(duo)(duo)種輸入(ru)源(yuan)給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)有幾個(ge)(ge)原因(yin)。有些應用(yong)(yong)也許需(xu)要(yao)(yao)擺(bai)脫電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)網(wang)的(de)(de)(de)(de)束縛，而靠太陽能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)板(ban)供電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。另(ling)一(yi)些應用(yong)(yong)則可(ke)能(neng)(neng)(neng)要(yao)(yao)求(qiu)(qiu)能(neng)(neng)(neng)方便地用(yong)(yong)交流(liu)適配器、汽車電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)或(huo)(huo)高(gao)壓工業及電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)信電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。無論出于何種原因(yin)，這(zhe)要(yao)(yao)求(qiu)(qiu)都給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)系統(tong)增(zeng)加了(le)極大的(de)(de)(de)(de)負擔。大多(duo)(duo)數電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器都利用(yong)(yong)降(jiang)壓型(開關或(huo)(huo)線性)架(jia)構，用(yong)(yong)高(gao)于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)最高(gao)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓源(yuan)給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)。以前(qian)的(de)(de)(de)(de)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器產品輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓一(yi)般(ban)限制(zhi)為大約(yue)30V。這(zhe)樣的(de)(de)(de)(de)限制(zhi)使設計(ji)(ji)師無法將(jiang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)信電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)或(huo)(huo)者(zhe)具(ju)42V開路(lu)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓的(de)(de)(de)(de)太陽能(neng)(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)板(ban)作(zuo)為可(ke)行的(de)(de)(de)(de)輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)。在(zai)有些情(qing)況(kuang)下，希(xi)望使用(yong)(yong)的(de)(de)(de)(de)輸入(ru)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源(yuan)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓涵蓋了(le)高(gao)于和低于電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)壓的(de)(de)(de)(de)范圍。設計(ji)(ji)一(yi)款應對此類難題(ti)的(de)(de)(de)(de)解決方案(an)通常需(xu)要(yao)(yao)混合使用(yong)(yong)高(gao)精(jing)度的(de)(de)(de)(de)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)檢(jian)測(ce)放大器、ADC、一(yi)個(ge)(ge)用(yong)(yong)于控制(zhi)充(chong)(chong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)的(de)(de)(de)(de)微(wei)處理(li)器、一(yi)個(ge)(ge)高(gao)性能(neng)(neng)(neng)DC/DC轉換器以及一(yi)個(ge)(ge)理(li)想二極管或(huo)(huo)多(duo)(duo)路(lu)復用(yong)(yong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)路(lu)。

　　強大的(de)充電解決方案(an)提供無與倫比(bi)的(de)靈活性

　　LTC4000可將任何外部補償的DC/DC電源轉換成具電源通路(PowerPath?)控制的全功能電池充電器。可由LTC4000驅動的典型DC/DC轉換器拓撲包括但不限于：降壓、升壓、降壓-升壓、SEPIC和反激式拓撲。該器件提供精確的輸入和充電電流調節，在3V至60V的寬輸入和輸出電壓范圍內工作，實現了與各種不同的輸入電壓源、以及不同尺寸和化學組成的電池組的兼容性。由于該器件的通用型配置，因此其典型應用十分廣泛，包括高功率電池充電器系統、高性能便(bian)攜式儀(yi)器、電池(chi)(chi)后備系統、配有工業電池(chi)(chi)的設備以及筆記(ji)本/小型筆記(ji)本電腦(nao)。

　　除了(le)可以(yi)(yi)與(yu)(yu)很多不同的DC/DC拓撲(pu)結合，LTC4000的高(gao)壓能力還允許該器件構成(cheng)強大和幾乎(hu)可使(shi)用任何(he)輸入電(dian)(dian)(dian)(dian)(dian)源(yuan)(參(can)見圖4和圖5)的電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)解決方案。為了(le)確(que)保來自(zi)這些(xie)輸入的功(gong)(gong)率傳送給合適的負(fu)載，LTC4000采用了(le)一(yi)(yi)種智能電(dian)(dian)(dian)(dian)(dian)源(yuan)通路拓撲(pu)，當輸入功(gong)(gong)率有限時(shi)，該拓撲(pu)可優先為系(xi)(xi)統負(fu)載供(gong)電(dian)(dian)(dian)(dian)(dian)。LTC4000控制外(wai)部PFET，以(yi)(yi)提(ti)供(gong)低損耗(hao)反(fan)向電(dian)(dian)(dian)(dian)(dian)流保護、電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)的低損耗(hao)充電(dian)(dian)(dian)(dian)(dian)和放電(dian)(dian)(dian)(dian)(dian)以(yi)(yi)及即時(shi)接通工作，這樣就可以(yi)(yi)確(que)保即使(shi)在電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)沒電(dian)(dian)(dian)(dian)(dian)或(huo)深度放電(dian)(dian)(dian)(dian)(dian)時(shi)，當一(yi)(yi)插上(shang)電(dian)(dian)(dian)(dian)(dian)源(yuan)，系(xi)(xi)統電(dian)(dian)(dian)(dian)(dian)源(yuan)就能立(li)即可用。外(wai)部檢測電(dian)(dian)(dian)(dian)(dian)阻(zu)器提(ti)供(gong)輸入電(dian)(dian)(dian)(dian)(dian)流和電(dian)(dian)(dian)(dian)(dian)池(chi)(chi)(chi)充電(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)流信息，從而使(shi)LTC4000能與(yu)(yu)涵(han)蓋mW至(zhi)kW功(gong)(gong)率范圍的轉換器一(yi)(yi)起使(shi)用。

圖4：LTC4000和LTC3789：6V至36V_IN、4節(jie)5A鋰離子電(dian)池充(chong)電(dian)器

圖5：圖4電路中系統負載(zai)為(wei)4A時效率(lv)隨VIN的變化

　　LTC4000的全功能電池充電控制器可為各種化學組成的電池充電，包括鋰離子/聚合物/磷酸、密封鉛酸(SLA)和鎳化學組成。該電池充電器還提(ti)供精確的電流(liu)檢(jian)測功能，從而在大電流(liu)應用情況下允許較低的檢(jian)測電壓。

　　結論

　　新式(shi)便(bian)攜(xie)式(shi)產(chan)品設計師的(de)(de)工(gong)作極富挑戰(zhan)性(xing)(xing)(xing)，尤(you)其(qi)是涉及(ji)到(dao)電源(yuan)(yuan)時(shi)。客(ke)戶不斷(duan)要求更多(duo)功(gong)(gong)能(neng)以導(dao)致需要更大(da)的(de)(de)功(gong)(gong)率，結(jie)果是電池越來越大(da)。同時(shi)，客(ke)戶希望可(ke)方(fang)便(bian)地用幾乎任(ren)何可(ke)用的(de)(de)電源(yuan)(yuan)給這些電池充電。盡管便(bian)攜(xie)式(shi)電源(yuan)(yuan)領(ling)域的(de)(de)這些趨勢造成了設計挑戰(zhan)，但(dan)是LTC4155和LTC4000讓設計工(gong)作變得簡單(dan)多(duo)了。在低壓系統中，LTC4155高(gao)(gao)效率地提(ti)供(gong)高(gao)(gao)達3.5A的(de)(de)充電電流，而且(qie)提(ti)供(gong)很多(duo)高(gao)(gao)性(xing)(xing)(xing)能(neng)功(gong)(gong)能(neng)。LTC4000可(ke)構成強大(da)的(de)(de)充電解決方(fang)案，而且(qie)幾乎可(ke)使用任(ren)何輸入，從而提(ti)供(gong)了無(wu)與倫比的(de)(de)性(xing)(xing)(xing)能(neng)和靈活性(xing)(xing)(xing)。