LTC3557EUF

FEATURES

APPLICATIONS

DESCRIPTION

USB Power Manager with

Li-Ion Charger and Three

Step-Down Regulators

The LTC.3557/LTC3557-1 is a highly integrated power

management and battery charger IC for single cell Li-Ion/

Polymer battery applications. It includes a PowerPathTM

manager with automatic load prioritization, a battery

charger, an ideal diode and numerous internal protection

features. Designed specifi cally for USB applications, the

LTC3557/LTC3557-1 power manager automatically limits

input current to a maximum of either 100mA or 500mA

for USB applications or 1A for wall adapter powered

applications. Battery charge current is automatically

reduced such that the sum of the load current and the

charge current does not exceed the programmed input

current limit. The LTC3557/LTC3557-1 also includes three

adjustable synchronous step-down switching regulators

and a high voltage buck regulator output controller with

Bat-Track that allows effi cient charging from supplies as

high as 38V. The LTC3557/LTC3557-1 is available in a low

profi le 4mm Å~ 4mm Å~ 0.75mm 28-pin QFN package.

■ Seamless Transition Between Input Power Sources:

Li-Ion Battery, USB, 5V Wall Adapter or High

Voltage Buck Regulator with Bat-TrackTM

■ 200mΩ Internal Ideal Diode Plus Optional External

Ideal Diode Controller Provides Low Loss Power

Path When Input Current is Limited or Unavailable

■ Triple Adjustable High Effi ciency Step-Down

Switching Regulators (600mA, 400mA, 400mA IOUT)

■ Pin Selectable Burst Mode. Operation

■ Full Featured Li-Ion/Polymer Battery Charger

■ 1.5A Maximum Charge Current with Thermal Limiting

■ Battery Float Voltage:

4.2V (LTC3557)

4.1V (LTC3557-1)

■ Low Profi le 4mm Å~ 4mm 28-Pin QFN Package

■ HDD-Based MP3 Players

■ PDA, PMP, PND/GPS

■ USB-Based Handheld Products

+

100mA/500mA

1000mA

HV SUPPLY

8V TO 38V

(TRANSIENTS

TO 60V)

USB OR

5V ADAPTER

CHARGE

RST

CC/CV

CHARGER

ALWAYS ON LDO

LTC3557/LTC3557-1

TRIPLE HIGH EFFICIENCY

STEP-DOWN

SWITCHING REGULATORS

HIGH VOLTAGE

BUCK DC/DC

0V

3.3V/25mA

SINGLE CELL

Li-Ion

VOUT

0.8V to 3.6V/600mA

0.8V to 3.6V/400mA

0.8V to 3.6V/400mA

NTC

35571 TA01a

, LT, LTC, LTM and Burst Mode are registered trademarks of Linear Technology

Corporation. Bat-Track and PowerPath are trademarks of Linear Technology Corporation.

All other trademarks are the property of their respective owners.

Protected by U.S. Patents, including 6522118, 6700364. Other patents pending.

产品特点
应用
说明
用USB电源管理器
锂离子电池充电器和三个
降压型稳压器
该LTC®3557/ LTC3557-1是一个高度集成的电源
适用于单节锂离子/管理和电池充电器IC
聚合物电池应用。它包括一个PowerPathTM
经理自动负载优先级，电池
充电器，一个理想二极管和众多的内部保护
产品特点。设计specifi为美云USB应用，
LTC3557/ LTC3557-1电源管理器会自动限制
到最大为100mA或500mA的输入电流
对于USB应用程序或1A的墙上适配器供电
应用。电池充电电流会自动
降低，使得负载电流之和的
充电电流不超过设定的输入
电流限制。的LTC3557/ LTC3557-1还包括三个
可调同步降压型开关稳压器
并配有高电压降压型稳压器输出控制器
电池跟踪，使艾菲cient充电的电源如
高达38V。的LTC3557/ LTC3557-1处于低可用
的简介型4mm x型4mm x0.75毫米28引脚QFN封装。
■输入电源之间无缝切换：
锂离子电池，USB，5V墙上适配器或高
电压降压稳压器与蝙蝠TrackTM
■在200mΩ内部理想二极管加上可选的外部
理想二极管控制器提供低损耗电源
路径当输入电流受限或不可用
■三重可调式高效率艾菲降压
开关稳压器（600毫安，400毫安，400毫安IOUT）
■引脚可选的突发模式工作
■全功能锂离子/聚合物电池充电器
■1.5A最大充电电流和热限制
■电池浮动电压：
4.2V（LTC3557）
4.1V（LTC3557-1）
■低的简介采用4mm x4毫米28引脚QFN封装
■基于硬盘的MP3播放器
■PDA，PMP，PND/ GPS
■基于USB的手持式产品
+
百毫安/500毫安
千毫安
HV SUPPLY
8V至38V
（瞬变
至60V）
USB OR
5V适配器
CHARGE
RST
CC/ CV
充电器
ALWAYS ON LDO
LTC3557/ LTC3557-1
TRIPLE高效率
STEP-DOWN
开关稳压器
高压
降压DC / DC
0V
3.3V/25毫安
单CELL
锂离子电池
VOUT
0.8V至3.6V/600毫安
0.8V至3.6V/400毫安
0.8V至3.6V/400毫安
NTC
35571 TA01a
，LT，LTC，LTM和Burst Mode是注册和凌特公司的商标
公司。蝙蝠跟踪和PowerPath的是凌特公司的商标。
所有其他商标均为其各自所有者的财产。
美国专利，其中包括6522118，6700364.其他未决专利保护。