凌(ling)力爾特(te)公司(si) (Linear Technology Corporation) 推出大功(gong)率、I2C 控制和(he)高(gao)(gao)效率的(de)電源通路(lu) (PowerPath?) 管(guan)理(li)器、理(li)想二(er)極管(guan)控制器及磷酸鐵鋰(li) (LiFePO4) 電池充電器 LTC4156，該(gai)器件適用(yong)于單(dan)節電池設(she)(she)備，例如便攜(xie)式醫療和(he)工業設(she)(she)備、備份設(she)(she)備以(yi)及其他高(gao)(gao)功(gong)率密度(du)電池供電應用(yong)。該(gai) IC 可(ke)高(gao)(gao)效地從各種(zhong)電源傳(chuan)輸(shu)(shu)(shu)高(gao)(gao)達 15W 的(de)功(gong)率，同時最大限(xian)度(du)地降低(di)功(gong)耗并減(jian)輕熱量的(de)限(xian)制。LTC4156 的(de)開(kai)關電源通路(lu)拓撲結構可(ke)無縫地管(guan)理(li)從兩個(ge)輸(shu)(shu)(shu)入(ru)源 (例如：一(yi)個(ge)墻上適配器和(he) USB 端口) 至器件的(de)可(ke)再充 LiFePO4 電池的(de)功(gong)率輸(shu)(shu)(shu)送，并在輸(shu)(shu)(shu)入(ru)功(gong)率有限(xian)時優先向系統負載(zai)供電。

因為 LTC4156 節省(sheng)了功率，所以(yi)(yi)該器件允許輸出負載(zai)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)超過輸入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源吸取的電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，從而能最大限度地利(li)用可用功率給電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，而不會超出輸入電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源供(gong)(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)規(gui)范的要求。例如，當從一個(ge) 5V/2A 交流(liu)(liu)適配(pei)器供(gong)(gong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)時(shi)(shi)，該 IC 的開關穩壓器高(gao)效(xiao)地將(jiang)可用 10W的 90% 以(yi)(yi)上(shang)(shang)之(zhi)功率傳送出去，從而可提(ti)供(gong)(gong)高(gao)達 2.4A 的充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)流(liu)(liu)，并實現較快的充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)速度。與(yu)普(pu)通開關電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池充電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)器不同，LTC4156 的特點是即時(shi)(shi)接通工作，以(yi)(yi)確(que)保即使電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池已深度放電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)，一插上(shang)(shang)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源插頭時(shi)(shi)就有系統(tong)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源。該器件支持(chi) USB OTG (On-The-Go)，因此無需任何額外組(zu)件，就可以(yi)(yi)反過來(lai)向 USB 端口提(ti)供(gong)(gong)一個(ge) 5V 電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)源。

通過一個簡單的兩線 I2C 端口，可在電路板上調整很多系統控制參數，包括充電電流、輸入電流 (包括 USB 2.0 和 3.0 兼容設置) 和浮置電壓 (3.45V、3.55V、3.60V 和3.80V)。該通信總線也允許 LTC4156 提供狀態信息，例如電池溫度、輸入電源狀態、充電器狀態(tai)和故障狀態(tai)信息。

LTC4156 的自主(zhu)型(xing)全(quan)功能(neng)單節 LiFePO4 電(dian)(dian)(dian)池充電(dian)(dian)(dian)器能(neng)夠提供高達 3.5A 的充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)和 15 種充電(dian)(dian)(dian)電(dian)(dian)(dian)流(liu)設定(ding)值。該充電(dian)(dian)(dian)器具備自動再充電(dian)(dian)(dian)、失(shi)效電(dian)(dian)(dian)池檢測、可編(bian)程安全(quan)定(ding)時器、熱敏電(dian)(dian)(dian)阻適宜溫度充電(dian)(dian)(dian)、可編(bian)程充電(dian)(dian)(dian)結束指(zhi)示 / 終止(zhi)、以及可編(bian)程中斷發生等功能(neng)。

LTC4156 的(de)(de)雙路(lu)(lu)輸入(ru)、優先級多路(lu)(lu)復用(yong)過壓保護 (OVP) 電(dian)(dian)(dian)路(lu)(lu)可(ke)避免因意(yi)外施加高(gao)電(dian)(dian)(dian)壓而造(zao)(zao)成的(de)(de)任何損(sun)壞。其理想二(er)極管控制器可(ke)確保始終能夠向(xiang) VOUT 提(ti)供足夠的(de)(de)功率，即(ji)使在(zai)輸入(ru)功率不(bu)足或(huo)缺失的(de)(de)情(qing)況下也不(bu)例外。為最大限度地(di)減少當器件連(lian)接(jie)至一(yi)個暫停模式(shi) USB 端(duan)口時的(de)(de)漏電(dian)(dian)(dian)流，由一(yi)個布設在(zai) VBUS 與 VOUT 之間(jian)的(de)(de) LDO 給應用(yong)提(ti)供可(ke)容許的(de)(de)暫停模式(shi) USB 電(dian)(dian)(dian)流。為了消除從(cong)制造(zao)(zao)到銷售過程中的(de)(de)電(dian)(dian)(dian)池消耗，一(yi)種“裝(zhuang)運及貯存”特性(xing)可(ke)將已經(jing)很低的(de)(de)電(dian)(dian)(dian)池待機電(dian)(dian)(dian)流減小至接(jie)近于零。LTC4156 為 LTC4155 提(ti)供了補充(chong)，后者擁有針對鋰(li)離子 / 鋰(li)聚合物電(dian)(dian)(dian)池供電(dian)(dian)(dian)型(xing)系統的(de)(de)相同特性(xing)集。

LTC4156 采用扁平 (0.75mm) 28 引腳 4mm x 5mm QFN 封(feng)裝，保證在 -40°C 至(zhi) 125°C 的溫度范(fan)圍內工作(zuo)。千片(pian)(pian)批(pi)購價為每片(pian)(pian) 4.07 美元(yuan)。

照(zhao)片說(shuo)明：具 OVP 和 USB OTG 的高效率 I2C 電源(yuan)管理器及 3.5A LiFePO4 電池(chi)充(chong)電器

性能(neng)概要：LTC4156

?大功率、高效率開關型 LiFePO4 電池充電器能可提供 3.5A 充電電流

?單(dan)片開關(guan)穩壓(ya)器可(ke)對有限的(de)可(ke)用(yong)輸入功率之利(li)用(yong)進行優化

?雙(shuang)輸入過(guo)壓保(bao)護控(kong)制器

?優(you)先級多路復用適用于多輸(shu)入(ru)

?I2C/SMBus 控(kong)制(zhi)以(yi)實現最佳(jia)系統性能并提(ti)供(gong)狀(zhuang)態信息

?在(zai)電池電量很低時即時接通工作

?電(dian)(dian)池理想二極管控(kong)制器以實現電(dian)(dian)源管理

?從電池到 USB 端口提供 USB OTG 供電

?全功(gong)能磷酸(suan)鐵(tie)鋰充電器具(ju) 4 種浮置電壓設(she)置 (3.45V、3.55V、3.60V 和 3.80V)

?用交(jiao)流(liu)適配器提供(gong) 3.5A 最大充(chong)電(dian)電(dian)流(liu)

?支持 USB 2.0 和(he) USB 3.0 規范(fan)

?扁平 (0.75mm) 28 引線 4mm x 5mm QFN 封裝