SLUSBH2G March   2013  – March 2019

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application Schematic
      2.      Charger Efficiency vs Input Voltage
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Electrical Characteristics
    7. 6.7 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 Maximum Power Point Tracking
      2. 7.3.2 Battery Undervoltage Protection
      3. 7.3.3 Battery Overvoltage Protection
      4. 7.3.4 Battery Voltage within Operating Range (VBAT_OK Output)
      5. 7.3.5 Storage Element / Battery Management
      6. 7.3.6 Programming OUT Regulation Voltage
      7. 7.3.7 Step Down (Buck) Converter
      8. 7.3.8 Nano-Power Management and Efficiency
    4. 7.4 Device Functional Modes
      1. 7.4.1 Main Boost Charger Disabled (Ship Mode) - (VSTOR > VSTOR_CHGEN and EN = HIGH)
      2. 7.4.2 Cold-Start Operation (VSTOR < VSTOR_CHGEN, VIN_DC > VIN(CS) and PIN > PIN(CS), EN = don't care)
      3. 7.4.3 Main Boost Charger Enabled (VSTOR > VSTOR_CHGEN and EN = LOW )
        1. 7.4.3.1 Buck Converter Enabled (VSTOR > VBAT_UV, EN = LOW and VOUT_EN = HIGH )
      4. 7.4.4 Thermal Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Energy Harvester Selection
      2. 8.1.2 Storage Element Selection
      3. 8.1.3 Inductor Selection
        1. 8.1.3.1 Boost Charger Inductor Selection
        2. 8.1.3.2 Buck Converter Inductor Selection
      4. 8.1.4 Capacitor Selection
        1. 8.1.4.1 VREF_SAMP Capacitance
        2. 8.1.4.2 VIN_DC Capacitance
        3. 8.1.4.3 VSTOR Capacitance
        4. 8.1.4.4 VOUT Capacitance
        5. 8.1.4.5 Additional Capacitance on VSTOR or VBAT
    2. 8.2 Typical Applications
      1. 8.2.1 Solar Application Circuit
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
      2. 8.2.2 TEG Application Circuit
        1. 8.2.2.1 Design Requirements
        2. 8.2.2.2 Detailed Design Procedure
        3. 8.2.2.3 Application Curves
      3. 8.2.3 Piezoelectric Application Circuit
        1. 8.2.3.1 Design Requirements
        2. 8.2.3.2 Detailed Design Procedure
        3. 8.2.3.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  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 Receiving Notification of Documentation Updates
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.4 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 bq25570 uses an integrated temperature sensor to monitor the junction temperature of the device. Once the temperature threshold is exceeded, the boost charger and buck converter are disabled. Once the temperature of the device drops below this threshold, the boost charger and buck converter resume operation. To avoid unstable operation near the overtemperature 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 charger is disabled. However, if the supply voltage drops to the VBAT_UV setting, the switch between VBAT and VSTOR will open and protect the battery even if the device is in thermal shutdown.