SLUSAH0F October   2011  – November 2019 BQ25504

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Solar Application Circuit
  4. Revision History
  5. Description (continued)
  6. Pin Configuration and Functions
    1.     Pin Functions
  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. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Maximum Power Point Tracking
      2. 8.3.2 Battery Undervoltage Protection
      3. 8.3.3 Battery Overvoltage Protection
      4. 8.3.4 Battery Voltage in Operating Range (VBAT_OK Output)
      5. 8.3.5 Nano-Power Management and Efficiency
    4. 8.4 Device Functional Modes
      1. 8.4.1 Cold-Start Operation (VSTOR < VSTOR_CHGEN, VIN_DC > VIN(CS) and PIN > PIN(CS))
      2. 8.4.2 Main Boost Charger Enabled (VSTOR > VSTOR_CHGEN, VIN_DC > VIN(DC) and EN = LOW )
      3. 8.4.3 Thermal Shutdown
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Storage Element Selection
      2. 9.1.2 Inductor Selection
      3. 9.1.3 Capacitor Selection
        1. 9.1.3.1 VREF_SAMP Capacitance
        2. 9.1.3.2 VIN_DC Capacitance
        3. 9.1.3.3 VSTOR Capacitance
        4. 9.1.3.4 Additional Capacitance on VSTOR or VBAT
    2. 9.2 Typical Applications
      1. 9.2.1 Solar Application Circuit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 TEG Application Circuit
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
      3. 9.2.3 MPPT Disabled, Low Impedance Source Application Circuit
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Thermal Considerations
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Zip Files
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Support Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Thermal Shutdown

Rechargeable Li-ion batteries need protection from damage due to operation at elevated temperatures. The application should provide this battery protection and ensure that the ambient temperature is never elevated greater than the expected operational range of 85°C.

The BQ25504 uses an integrated temperature sensor to monitor the junction temperature of the device. If the OT_PROG pin is tied low, then the temperature threshold for thermal protection is set to TSD_ProtL which is 65°C typically. If the OT_PROG is tied high, then the temperature is set to TSD_ProtH which is 120°C typically. Once the temperature threshold is exceeded, the boost converter/charger is disabled and charging ceases. Once the temperature of the device drops below this threshold, the boost converter and or charger can resume operation. To avoid unstable operation near the overtemp threshold, a built-in hysteresis of approximately 5°C has been implemented. Care should be taken to not over discharge the battery in this condition since the boost converter/charger is disabled. However, if the supply voltage drops to the VBAT_UV setting, then the switch between VBAT and VSTOR will open and protect the battery even if the device is in thermal shutdown.