SLUS893B March   2010  – June 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  Battery Voltage Regulation
      2. 8.3.2  Battery Current Regulation
      3. 8.3.3  Precharge
      4. 8.3.4  Charge Termination, Recharge, and Safety Timer
      5. 8.3.5  Power Up
      6. 8.3.6  Enable and Disable Charging
      7. 8.3.7  Automatic Internal Soft-Start Charger Current
      8. 8.3.8  Converter Operation
      9. 8.3.9  Synchronous and Nonsynchronous Operation
      10. 8.3.10 Cycle-by-Cycle Charge Undercurrent
      11. 8.3.11 Input Overvoltage Protection (ACOV)
      12. 8.3.12 Input Undervoltage Lockout (UVLO)
      13. 8.3.13 Battery Overvoltage Protection
      14. 8.3.14 Cycle-by-Cycle Charge Overcurrent Protection
      15. 8.3.15 Thermal Shutdown Protection
      16. 8.3.16 Temperature Qualification
      17. 8.3.17 Timer Fault Recovery
      18. 8.3.18 PG Output
      19. 8.3.19 CE (Charge Enable)
      20. 8.3.20 Charge Status Outputs
      21. 8.3.21 Battery Detection
    4. 8.4 Device Functional Modes
  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 Inductor Selection
        2. 9.2.2.2 Input Capacitor
        3. 9.2.2.3 Output Capacitor
        4. 9.2.2.4 Power MOSFET Selection
        5. 9.2.2.5 Input Filter Design
        6. 9.2.2.6 Inductor, Capacitor, and Sense Resistor Selection Guidelines
        7. 9.2.2.7 Maximum Output Capacitance
      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 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • 300-kHz NMOS-NMOS Synchronous Buck Converter
  • Stand-Alone Charger Designed Specifically for Lithium Phosphate
  • 5-V to 28-V VCC Operating Range, Supports 1 to 7 Battery Cells
  • High-Accuracy Voltage and Current Regulation
    • ±0.5% Charge Voltage Accuracy
    • ±3% Charge Current Accuracy
  • Integration
    • Internal Loop Compensation
    • Internal Soft Start
  • Safety
    • Input Overvoltage Protection
    • Battery Thermistor Sense Suspend Charge at Hot/Cold Charge Suspend and Automatically ICHARGE/8 at WARM/COOL
    • Battery Detection
    • Built-In Safety Timer
    • Charge Overcurrent Protection
    • Battery Short Protection
    • Battery Overvoltage Protection
    • Thermal Shutdown
  • Status Outputs
    • Adapter Present
    • Charger Operation Status
  • Charge Enable Pin
  • 6-V Gate Drive for Synchronous Buck Converter
  • 30-ns Driver Dead Time and 99.95% Maximum Effective Duty Cycle
  • 16-Pin 3.5-mm × 3.5-mm QFN Package
  • Energy Star Low Iq
    • < 15-μA Off-State Battery Discharge Current
    • < 1.5-mA Off-State Input Quiescent Current

2 Applications

  • Power Tools and Portable Equipment
  • Personal Digital Assistants
  • Handheld Terminals
  • Industrial and Medical Equipment
  • Netbooks, Mobile Internet Devices, and Ultramobile PCs

3 Description

The bq24620 device is a highly integrated lithium phosphate switched-mode battery charge controller. The device offers a constant-frequency synchronous switching PWM controller with high-accuracy charge current and voltage regulation, charge preconditioning, termination, and charge status monitoring.

The bq24620 charges the battery in three phases: preconditioning, constant current, and constant voltage.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
bq24620 VQFN (16) 3.50 mm × 3.50 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

bq24620 Simplified schematic.gif

4 Revision History

Changes from A Revision (October 2011) to B Revision

  • Added ESD Ratings table, Feature Description section, Device Functional Modes, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo

Changes from * Revision (March 2010) to A Revision

  • Changed description for PH and BTST pinsGo
  • Replaced Thermal Information tableGo
  • Corrected Equation 11Go