SLUSCC8C July   2015  – October 2022 BQ25895M

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 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 Timing Requirements
    7. 7.7 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Functional Block Diagram
    2. 8.2 Feature Description
      1. 8.2.1  Device Power-On-Reset (POR)
      2. 8.2.2  Device Power Up from Battery without Input Source
      3. 8.2.3  Device Power Up from Input Source
        1. 8.2.3.1 Power Up REGN Regulation (LDO)
        2. 8.2.3.2 Poor Source Qualification
        3. 8.2.3.3 Input Source Type Detection
          1. 8.2.3.3.1 D+/D– Detection Sets Input Current Limit
          2. 8.2.3.3.2 Force Input Current Limit Detection
        4. 8.2.3.4 Input Voltage Limit Threshold Setting (VINDPM Threshold)
        5. 8.2.3.5 Converter Power-Up
      4. 8.2.4  Input Current Optimizer (ICO)
      5. 8.2.5  Boost Mode Operation from Battery
      6. 8.2.6  Power Path Management
        1. 8.2.6.1 Narrow VDC Architecture
        2. 8.2.6.2 Dynamic Power Management
        3. 8.2.6.3 Supplement Mode
      7. 8.2.7  Battery Charging Management
        1. 8.2.7.1 Autonomous Charging Cycle
        2. 8.2.7.2 Battery Charging Profile
        3. 8.2.7.3 Charging Termination
        4. 8.2.7.4 Resistance Compensation (IRCOMP)
        5. 8.2.7.5 Thermistor Qualification
          1. 8.2.7.5.1 Cold/Hot Temperature Window in Charge Mode
          2. 8.2.7.5.2 Cold/Hot Temperature Window in Boost Mode
        6. 8.2.7.6 Charging Safety Timer
      8. 8.2.8  Battery Monitor
      9. 8.2.9  Status Outputs (STAT, and INT)
        1. 8.2.9.1 Charging Status Indicator (STAT)
        2. 8.2.9.2 Interrupt to Host (INT)
      10. 8.2.10 BATET (Q4) Control
        1. 8.2.10.1 BATFET Disable Mode (Shipping Mode)
        2. 8.2.10.2 BATFET Enable (Exit Shipping Mode)
        3. 8.2.10.3 BATFET Full System Reset
      11. 8.2.11 Current Pulse Control Protocol
      12. 8.2.12 Input Current Limit on ILIM
      13. 8.2.13 Thermal Regulation and Thermal Shutdown
        1. 8.2.13.1 Thermal Protection in Buck Mode
        2. 8.2.13.2 Thermal Protection in Boost Mode
      14. 8.2.14 Voltage and Current Monitoring in Buck and Boost Mode
        1. 8.2.14.1 Voltage and Current Monitoring in Buck Mode
          1. 8.2.14.1.1 Input Overvoltage (ACOV)
          2. 8.2.14.1.2 System Overvoltage Protection (SYSOVP)
        2. 8.2.14.2 Current Monitoring in Boost Mode
          1. 8.2.14.2.1 Boost Mode Overvoltage Protection
      15. 8.2.15 Battery Protection
        1. 8.2.15.1 Battery Overvoltage Protection (BATOVP)
        2. 8.2.15.2 Battery Over-Discharge Protection
        3. 8.2.15.3 System Overcurrent Protection
      16. 8.2.16 Serial Interface
        1. 8.2.16.1 Data Validity
        2. 8.2.16.2 START and STOP Conditions
        3. 8.2.16.3 Byte Format
        4. 8.2.16.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 8.2.16.5 Target Address and Data Direction Bit
        6. 8.2.16.6 Single Read and Write
        7. 8.2.16.7 Multi-Read and Multi-Write
    3. 8.3 Device Functional Modes
      1. 8.3.1 Host Mode and Default Mode
    4. 8.4 Register Maps
      1. 8.4.1  REG00
      2. 8.4.2  REG01
      3. 8.4.3  REG02
      4. 8.4.4  REG03
      5. 8.4.5  REG04
      6. 8.4.6  REG05
      7. 8.4.7  REG06
      8. 8.4.8  REG07
      9. 8.4.9  REG08
      10. 8.4.10 REG09
      11. 8.4.11 REG0A
      12. 8.4.12 REG0B
      13. 8.4.13 REG0C
      14. 8.4.14 REG0D
      15. 8.4.15 REG0E
      16. 8.4.16 REG0F
      17. 8.4.17 REG10
      18. 8.4.18 REG11
      19. 8.4.19 REG12
      20. 8.4.20 REG13
      21. 8.4.21 REG14
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection
        2. 9.2.2.2 Buck Input Capacitor
        3. 9.2.2.3 System Output Capacitor
      3. 9.2.3 Application Curves
    3. 9.3 System Examples
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    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

8.2.5 Boost Mode Operation from Battery

The device supports boost converter operation to deliver power from the battery to other portable devices through PMID pin. The boost mode output current rating supports maximum output current up to 3.1 A (down-to VOTG_BAT1) or 2.4A (down-to VOTG_BAT2) to charge smartphone and tablet at fast charging rate. The boost operation can be enabled if the conditions are valid:

  1. BAT above VOTG_BAT_EN
  2. VBUS less than BAT+VSLEEP (in sleep mode)
  3. Boost mode operation is enabled (OTG pin HIGH and OTG_CONFIG bit =1)
  4. Voltage at TS (thermistor) pin is within range configured by Boost Mode Temperature Monitor as configured by BHOT and BCOLD bits
  5. After 30 ms delay from boost mode enable

In boost mode, the device employs a 500 KHz or 1.5 MHz (selectable using BOOST_FREQ bit) step-up switching regulator based on system requirements. To avoid frequency change during boost mode operations, write to boost frequency configuration bit (BOOST_FREQ) is ignored when OTG_CONFIG is set. To improve boost mode light-load efficiency, the device by default switches to PFM control at light load. The PFM mode can be disabled by setting PFM_OTG_DIS bit in i2C.

During boost mode, the status register VBUS_STAT bits is set to 111, the VBUS output is 5.126V by default (selectable via BOOSTV register bits). The boost output is maintained when BAT is above VOTG_BAT threshold

In additon, the MIN_VBAT_SEL bit can be changed to select the minimum battery voltage threshold to automatically exit boost mode.