1 Features

• Small 3.5-mm × 4.5-mm QFN Package
• Designed for Single-Cell Li-Ion- or Li-Polymer-Based Portable Applications
• Integrated Dynamic Power-Path Management (DPPM) Feature Allowing the AC Adapter or the USB Port to Simultaneously Power the System and Charge the Battery
• Power Supplement Mode Allows Battery to Supplement the USB or AC Input Current
• Autonomous Power Source Selection (AC Adapter or USB)
• Integrated USB Charge Control With Selectable 100-mA and 500-mA Maximum Input Current Regulation Limits
• Dynamic Total Current Management
  for USB
• Supports Up to 2-A Total Current
• 3.3-V Integrated LDO Output
• Thermal Regulation for Charge Control
• Charge Status Outputs for LED or System Interface Indicates Charge and Fault Conditions
• Reverse Current, Short-Circuit, and Thermal Protection
• Power Good (AC Adapter and USB Port Present) Status Outputs
• Charge Voltage Options: 4.1 V, 4.2 V, or 4.36 V

2 Applications

• Smart Phones and PDAs
• MP3 Players
• Digital Cameras Handheld Devices
• Internet Appliances

3 Description

The bqTINY™ III-series of devices are highly integrated Li-ion linear chargers and system power-path management devices targeted at space-limited portable applications. The bqTINY III-series offer integrated USB-port and DC supply (AC adapter), power-path management with autonomous power-source selection, power FETs and current sensors, high accuracy current and voltage regulation, charge status, and charge termination, in a single monolithic device.

The bqTINY III-series powers the system while independently charging the battery. This feature reduces the charge and discharge cycles on the battery, allows for proper charge termination and allows the system to run with an absent or defective battery pack. This feature also allows for the system to instantaneously turn on from an external power source in the case of a deeply discharged battery pack. The IC design is focused on supplying continuous power to the system when available from the AC, USB, or battery sources.

1. For all available packages, see the orderable addendum at the end of the datasheet.

4 Power Flow Diagram

1. See Figure 2 and Functional Block Diagram for more detailed feature information.

2. P-FET back gate body diodes are disconnected to prevent body diode conduction.