4A 單片同步降壓型電池充電器 LT3651-4.2，該器(qi)件面(mian)向單節(jie)鋰(li)離子/聚合物電池應用(yong)(yong)。LT3651-4.2 接受(shou)高(gao)達 32V 的(de)輸入(ru)，并(bing)具(ju) 40V 最(zui)(zui)大絕(jue)對額定(ding)(ding)值(zhi)以增加系(xi)統裕(yu)度。充電電流可編程至高(gao)達 4A，而(er)且是動態可調節(jie)的(de)，而(er)充分集(ji)成(cheng)(cheng)的(de)同步(bu)電源電路最(zui)(zui)大限度地降低了功耗并(bing)節(jie)省(sheng)了電路板空間(jian)。用(yong)(yong)戶可選定(ding)(ding)時(shi)器(qi)或 C/10 終(zhong)止無需外部微控(kong)制器(qi)，簡化了設計。LT3651-4.2 不需要外部高(gao)準確度電阻器(qi)來(lai)設定(ding)(ding)浮置電壓，從而(er)進一步(bu)節(jie)省(sheng)了成(cheng)(cheng)本(ben)和空間(jian)。應用(yong)(yong)包括工業手持式儀表、12V 至 24V 汽車和重(zhong)型設備應用(yong)(yong)、臺式插座充電器(qi)以及筆記本(ben)或平板電腦。

　　LT3651-4.2 的(de)可編(bian)程(cheng)開關頻率 (200kHz 至 1MHz) 使設計(ji)師能平衡(heng)解決方案尺寸、功率損耗和濾波需求。同(tong)步工(gong)作實(shi)現(xian)了高達 90% 的(de)充電(dian)(dian)(dian)(dian)效率。最終浮置電(dian)(dian)(dian)(dian)壓(ya)準(zhun)確(que)度為(wei)(wei) ?0.5%，充電(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)流準(zhun)確(que)度為(wei)(wei) ?7.5%，以及 C/10 檢(jian)(jian)測準(zhun)確(que)度為(wei)(wei) ?4%。一(yi)旦充電(dian)(dian)(dian)(dian)終止，LT3651-4.2 就自動地(di)進入低電(dian)(dian)(dian)(dian)流備(bei)用模(mo)式，該模(mo)式將輸(shu)入電(dian)(dian)(dian)(dian)源電(dian)(dian)(dian)(dian)流降至 80uA。停機時，輸(shu)入偏置電(dian)(dian)(dian)(dian)流降至 15uA。由于(yu)在所(suo)有(you)非(fei)充電(dian)(dian)(dian)(dian)周期中僅從(cong)電(dian)(dian)(dian)(dian)池(chi)泄漏(lou) <1uA 的(de)電(dian)(dian)(dian)(dian)流，所(suo)以 LT3651-4.2 可最大限(xian)度地(di)延長電(dian)(dian)(dian)(dian)池(chi)壽(shou)命。就安全性(xing)和自主充電(dian)(dian)(dian)(dian)控制而言，該器件(jian)包括自動重啟和預(yu)處理、一(yi)個用于(yu)溫(wen)度合格充電(dian)(dian)(dian)(dian)的(de)熱敏電(dian)(dian)(dian)(dian)阻(zu)輸(shu)入、可編(bian)程(cheng)輸(shu)入電(dian)(dian)(dian)(dian)流限(xian)制、壞電(dian)(dian)(dian)(dian)池(chi)檢(jian)(jian)測以及二進制編(bian)碼的(de)狀態輸(shu)出引腳。

　　LT3651-4.2 采用扁平 (0.75mm) 36 引腳 5mm x 6mm QFN 封裝，同時提供 E 級和(he)I 級版本，保證工作在(zai) -40?C 至(zhi) 125?C 溫度范圍。千片批購價分別為每片 4.13 美元(yuan)和(he) 4.75 美元(yuan)。兩節(jie) 8.2V 和(he) 8.4V 版本以(yi)及一節(jie) 4.1V 版本計劃(hua)在(zai)未來 2 至(zhi) 3 個月內推出(chu)。

照片說明： 32V、4A 同步單片式單節鋰離子電池充電器