SLUSA44A March   2010  – July 2015

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Output Voltage Regulation
      2. 7.3.2  Output Current Regulation
      3. 7.3.3  Power Up
      4. 7.3.4  Enable and Disable Charging
      5. 7.3.5  Automatic Internal Soft-Start Charger Current
      6. 7.3.6  Converter Operation
      7. 7.3.7  Synchronous and Nonsynchronous Operation
      8. 7.3.8  Input Overvoltage Protection (ACOV)
      9. 7.3.9  Output Overvoltage Protection
      10. 7.3.10 Cycle-by-Cycle Charge Overcurrent Protection
      11. 7.3.11 Thermal Shutdown Protection
      12. 7.3.12 Temperature Qualification
      13. 7.3.13 CE (Charge Enable)
      14. 7.3.14 PG Output
      15. 7.3.15 Charge Status Outputs
    4. 7.4 Device Functional Modes
      1. 7.4.1 Constant Current Mode
      2. 7.4.2 Constant Voltage Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Inductor Selection
        2. 8.2.2.2 Input Capacitor
        3. 8.2.2.3 Output Capacitor
        4. 8.2.2.4 Power MOSFETs Selection
        5. 8.2.2.5 Input Filter Design
        6. 8.2.2.6 Inductor, Capacitor, and Sense Resistor Selection Guidelines
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9 Power Supply Recommendations

For proper operation of bq24640, VCC must be from 5 V to 28 V. To begin charging, VCC must be higher than SRN by at least 500 mV (otherwise, the device will be in sleep mode). TI recommends an input voltage of at least 1.5 V to 2 V higher than the super capacitor voltage, taking into consideration the DC losses in the high-side FET (Rdson), inductor (DCR), the input diode drop, and current-sense resistor (between SRP and SRN). Power limit for the input supply must be greater than the maximum power required for super capacitor charging.