General Description
The AAT3685 BatteryManager™ is a highly integrated single cell lithium-ion/polymer battery charger IC designed to operate with USB port or line adapter inputs. It requires the minimum number of external components.
The AAT3685 precisely regulates battery charge voltage and current for 4.2V lithium-ion/polymer battery cells. Regardless of the type of input power source (USB or adapter), the AAT3685 can be programmed for two separate constant current charge levels up to 1A. An optional Charge Reduction Loop is built in to allow users to charge the battery with available current from the charge supply, while keeping the port voltage regulated.

Features
• Adapter or USB Charger
    — Programmable up to 1A Max
• 4.0V to 5.5V Input Voltage Range
• High Level of Integration With Internal:
    — Charging Device
    — Reverse Blocking Diode
    — Current Sensing
• Automatic Recharge Sequencing
• Charge Reduction Loop
• Battery Temperature Monitoring
• Full Battery Charge Auto Turn-Off
• Over-Voltage Protection
• Emergency Thermal Protection
• Power On Reset and Soft Start
• Serial Interface Status Reporting
• 12-Pin 3x3mm TDFN Package

Applications
• Cellular Telephones
• Digital Still Cameras
• Hand-Held PCs
• MP3 Players
• Personal Data Assistants (PDAs)
• Other Lithium-Ion/Polymer Battery-Powered Devices