SLUSDC7A March   2020  – November 2020 BQ25306

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 Timing Requirements
    7. 8.7 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 Device Power Up
        1. 9.3.1.1 Power-On-Reset (POR)
        2. 9.3.1.2 REGN Regulator Power Up
        3. 9.3.1.3 Charger Power Up
        4. 9.3.1.4 Charger Enable and Disable by EN Pin
        5. 9.3.1.5 Device Unplugged from Input Source
      2. 9.3.2 Battery Charging Management
        1. 9.3.2.1 Battery Charging Profile
        2. 9.3.2.2 Precharge
        3. 9.3.2.3 Charging Termination
        4. 9.3.2.4 Battery Recharge
        5. 9.3.2.5 Charging Safety Timer
        6. 9.3.2.6 Thermistor Temperature Monitoring
      3. 9.3.3 Charging Status Indicator (STAT)
      4. 9.3.4 Protections
        1. 9.3.4.1 Voltage and Current Monitoring
          1. 9.3.4.1.1 Input Over-Voltage Protection
          2. 9.3.4.1.2 Input Voltage Dynamic Power Management (VINDPM)
          3. 9.3.4.1.3 Input Current Limit
          4. 9.3.4.1.4 Cycle-by-Cycle Current Limit
        2. 9.3.4.2 Thermal Regulation and Thermal Shutdown
        3. 9.3.4.3 Battery Protection
          1. 9.3.4.3.1 Battery Over-Voltage Protection (VBAT_OVP)
          2. 9.3.4.3.2 Battery Short Circuit Protection
        4. 9.3.4.4 ICHG Pin Open and Short Protection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Disable Mode, HiZ Mode, Sleep Mode, Charge Mode, Termination Mode, and Fault Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Typical Application
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Charge Voltage Settings
          2. 10.2.1.2.2 Charge Current Setting
          3. 10.2.1.2.3 Inductor Selection
          4. 10.2.1.2.4 Input Capacitor
          5. 10.2.1.2.5 Output Capacitor
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Typical Application with External Power Path
        1. 10.2.2.1 Design Requirements
      3. 10.2.3 Typical Application with MCU Programmable Charge Current
        1. 10.2.3.1 Design Requirements
  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. 13.2 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

9.3.2.5 Charging Safety Timer

The device has built-in safety timer to prevent extended charging cycle due to abnormal battery conditions. The safety timer is 20 hours when the battery voltage is above VBAT_LOWV threshold and 2 hours below VBAT_LOWV threshold. When the safety timer expires, charge is suspended until the safety timer is reset. Safety timer is reset and charge starts under one of the following conditions:

  • Battery voltage falls below recharge threshold
  • VBUS voltage is recycled
  • EN pin is toggled
  • Battery voltage transits across VBAT_SHORT threshold
  • Battery voltage transits across VBAT_LOWV threshold

If the safety timer expires and the battery voltage is above recharge threshold, the charger is suspended and the STAT pin is open. If the safety timer expires and the battery voltage is below the recharge threshold, the charger is suspended and the STAT pin blinks to indicate a fault. The safety timer fault is cleared with safety timer reset.

During input current regulation, thermal regulation, the safety timer counts at half the original clock frequency and the safety timer is doubled. During TS fault, VBUS_OVP, VBAT_OVP, ICHG pin open and short, FB pin fault, and IC thermal shutdown faults, the safety timer is suspended. Once the fault(s) is clear, the safety timer resumes to count.