Linear 公司的LTC4155是集成了I2C控制和USB OTG雙路輸入電源管理器和3.5A鋰電池充電器,輸入電源5V如USB端口和適配器,主要用在平板電腦,超薄移動(dòng)電腦,智能手機,數碼相機,GPS,PDA,視頻媒體播放器以及手持媒體設備.本文介紹了LTC4155主要特性,方框圖以及多種應用電路.
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應用:
Tablet PCs
Ultra Mobile PCs
Video Media Players
Digital Cameras, GPS, PDAs
Smart Phones
Portable Medical Devices

圖1. LTC4155方框圖

圖2. LTC4155雙輸入正負電源保護電路圖

圖3. LTC4155最少元件的單個(gè)USB輸入應用電路圖

圖4. LTC4155單輸入過(guò)壓保護(USB輸入電流100mA)應用電路圖


圖5. LTC4155單輸入欠壓/過(guò)壓保護(USB輸入電流默認)應用電路圖

圖4. LTC4155雙輸入欠壓/過(guò)壓保護(USB輸入電流100mA)應用電路圖