SLUSE31A April   2020  – February 2021 BQ25968

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Charging System
      2. 9.3.2  Battery Charging Profile
      3. 9.3.3  Control State Diagram for System Implementation
      4. 9.3.4  Device Power Up
      5. 9.3.5  Switched Cap Function
        1. 9.3.5.1 Theory of Operation
      6. 9.3.6  Charging Start-Up
      7. 9.3.7  Integrated 16-Bit ADC for Monitoring and Smart Adapter Feedback
      8. 9.3.8  Device Internal Thermal Shutdown, TSBUS, and TSBAT Temperature Monitoring
      9. 9.3.9  INT Pin, STAT, FLAG, and MASK Registers
      10. 9.3.10 CDRVH and CDRVL_ADDRMS Functions
      11. 9.3.11 Parallel Operation Using Master and Slave Modes
    4. 9.4 Device Functional Modes
      1. 9.4.1 Device Modes and Protection Status
        1. 9.4.1.1 Input Overvoltage, Overcurrent, Undercurrent and Short-Circuit Protection
        2. 9.4.1.2 Battery Overvoltage and Overcurrent Protection
        3. 9.4.1.3 Cycle-by-Cycle Current Limit
    5. 9.5 Programming
      1. 9.5.1 F/S Mode Protocol
    6. 9.6 Register Maps
      1. 9.6.1 Customer Registers
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Standalone Application Information (for use with switching charger)
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Parallel BQ25968 for Higher Power Applications
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curve
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Device Nomenclature
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.2 Battery Charging Profile

The system will have a specific battery charging profile that is unique due to the switched cap architecture. During the trickle charge and precharge of the battery up to 3.5 V, the charging will be controlled by the primary charger (BQ25890 in Figure 9-1). Once the battery voltage reaches 3.5 V, the adapter can negotiate for a higher bus voltage, enable the BQ25968 charging, and regulate the current on VBUS to charge the battery. In the CC phase, the protection in the BQ25968 will not regulate the battery voltage, but will provide feedback to the system to increase/decrease current as needed, as well as disable the output if the voltage is exceeded. Once the CV point is reached, the BQ25968 will provide feedback to the adapter to reduce the current, effectively tapering the current until a point where the primary charger takes over again. This charging profile is shown in Figure 9-2.

GUID-CF94578D-D8D7-4F1B-B646-65BBB4B84383-low.gifFigure 9-2 BQ25968 System Charging Profile