Linear 公司的LTC4155是集成了I2C控制和USB OTG双路输入电源管理器和3.5A锂电池充电器,输入电源5V如USB端口和适配器,主要用在平板电脑,超薄移动电脑,智能手机,数码相机,GPS,PDA,视频媒体播放器以及手持媒体设备.本文介绍了LTC4155主要特性,方框图以及多种应用电路.
Dual Input Power Manager/3.5A Li-Ion Battery Charger with I2C Control and USB OTG
The LTC®4155 is a 15 watt I2C controlled power manager with PowerPath™ instant-on operation, high efficiency switching battery charging and USB compatibility. The LTC4155 seamlessly manages power distribution from two 5V sources, such as a USB port and a wall adapter, to a single-cell rechargeable Lithium-Ion/Polymer battery and a system load.
The LTC4155’s switching battery charger automatically limits its input current for USB compatibility, or may draw up to 3A from a high power wall adapter. The high efficiency step-down switching charger is designed to provide maximum power to the application and reduced heat in high power density applications.
I2C adjustability of input current, charge current, battery float voltage, charge termination, and many other parameters allows maximum flexibility. I2C status reporting of key system and charge parameters facilitates intelligent control decisions. USB On-The-Go support provides 5V power back to the USB port without any additional components.
A dual-input, priority multiplexing, overvoltage protection circuit guards the LTC4155 from high voltage damage on the VBUS pin.
The LTC4155 is available in the low profile 28-lead 4mm x5mmx0.75mm QFN surface mount package.

LTC4155主要特性:
High Efficiency Charger Capable of 3.5A Charge Current
Monolithic Switching Regulator Makes Optimal Use of Limited Power and Thermal Budget
Dual Input Overvoltage Protection Controller
Priority Multiplexing for Multiple Inputs
I2C/SMBus Control and Status Feedback
NTC Thermistor ADC for Temperature Dependent Charge Algorithms (JEITA)
Instant-On Operation with Low Battery
Battery Ideal Diode Controller for Power Management
USB On-The-Go Power Delivery to the USB Port
Full Featured Li-Ion/Polymer Battery Charger with Four Float Voltage Settings
28-Lead 4mmx5mm QFN Package

LTC4155应用:
Tablet PCs
Ultra Mobile PCs
Video Media Players
Digital Cameras, GPS, PDAs
Smart Phones
Portable Medical Devices

图1. LTC4155方框图

图2. LTC4155双输入正负电源保护电路图

图3. LTC4155最少元件的单个USB输入应用电路图

图4. LTC4155单输入过压保护(USB输入电流100mA)应用电路图


图5. LTC4155单输入欠压/过压保护(USB输入电流默认)应用电路图

图4. LTC4155双输入欠压/过压保护(USB输入电流100mA)应用电路图