SLUS977B September   2009  – August 2015

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Input Overvoltage Protection
      2. 8.3.2 Input Overcurrent Protection
      3. 8.3.3 Battery Overvoltage Protection
      4. 8.3.4 Thermal Protection
      5. 8.3.5 Enable Function
      6. 8.3.6 PGATE Output
    4. 8.4 Device Functional Modes
      1. 8.4.1 OPERATION Mode
      2. 8.4.2 POWER-DOWN Mode
      3. 8.4.3 POWER-ON RESET Mode
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Selection of RBAT
        2. 9.2.2.2 Selection of RCE
        3. 9.2.2.3 Selection of Input and Output Bypass Capacitors
        4. 9.2.2.4 Selection of the PGATE External MOSFET
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Community Resources
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

1 Features

  • Provides Protection for Three Variables:
    • Input Overvoltage
    • Input Overcurrent with Current Limiting
    • Battery Overvoltage
  • Maximum Input Voltage of 30 V
  • Supports Up to 1.5-A Input Current
  • Robust Against False Triggering Due to Current Transients
  • Thermal Shutdown
  • LDO Mode Voltage Regulation of 5 V
  • Available in Space-Saving Small 2 mm × 2 mm 8-Pin WSON Package

2 Applications

  • Mobile and Smart Phones
  • PDAs
  • MP3 Players
  • Low-Power Handheld Devices
  • Bluetooth™ Headsets

3 Description

The bq24308 device is a highly integrated circuit (IC) designed to provide protection to Li-ion batteries from failures of the charging circuit. The device continuously monitors the input voltage, the input current, and the battery voltage. In case of an input overvoltage condition, the device immediately removes power from the charging circuit by turning off an internal switch. In the case of an overcurrent condition, it limits the system current to a safe value for a blanking duration before turning the switch off. Battery voltage may also be monitored and if the battery voltage exceeds the specified value the internal switch is turned off. Additionally, the device also monitors its own die temperature and switches off if it becomes too hot.

The input overcurrent threshold can be increased using an external resistor. The device also offers optional protection against reverse voltage at the input using an external P-channel FET.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
bq24308 WSON (8) 2.00 mm × 2.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Typical Application Circuit

bq24308 app_sch_lus977.gif