SLVSDU0B September   2017  – September 2019 BQ25910

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Simplified Schematic
  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 Timing Requirements
    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  Device Power-On-Reset (POR)
      2. 7.3.2  Device Power Up from Battery without Input Source
      3. 7.3.3  Device Power Up from Input Source
      4. 7.3.4  Power Up REGN LDO
      5. 7.3.5  Poor Source Qualification
      6. 7.3.6  Converter Power-Up
      7. 7.3.7  Three-Level Buck Converter Theory of Operation
      8. 7.3.8  Host Mode and Default Mode
        1. 7.3.8.1 Host Mode and Default Mode in BQ25910
      9. 7.3.9  Battery Charging Management
        1. 7.3.9.1 Autonomous Charging Cycle
      10. 7.3.10 Master Charger and Parallel Charger Interactions
      11. 7.3.11 Battery Charging Profile
        1. 7.3.11.1 Charging Termination
        2. 7.3.11.2 Differential Battery Voltage Remote Sensing
        3. 7.3.11.3 Charging Safety Timer
    4. 7.4 Device Functional Modes
      1. 7.4.1 Lossless Current Sensing
      2. 7.4.2 Dynamic Power Management
      3. 7.4.3 Interrupt to Host (INT)
      4. 7.4.4 Protections
        1. 7.4.4.1 Voltage and Current Monitoring
          1. 7.4.4.1.1 Input Over-Voltage (VVBUS_OV)
          2. 7.4.4.1.2 Input Under-Voltage (VPOORSRC)
          3. 7.4.4.1.3 Flying Capacitor Over- or Under-Voltage Protection (VCFLY_OVP and VCFLY_UVP)
          4. 7.4.4.1.4 Over Current Protection
        2. 7.4.4.2 Thermal Regulation and Thermal Shutdown
        3. 7.4.4.3 Battery Protection
          1. 7.4.4.3.1 Battery Over-Voltage Protection (BATOVP)
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
      2. 7.5.2 Data Validity
      3. 7.5.3 START and STOP Conditions
      4. 7.5.4 Byte Format
      5. 7.5.5 Acknowledge (ACK) and Not Acknowledge (NACK)
      6. 7.5.6 Slave Address and Data Direction Bit
      7. 7.5.7 Single Read and Write
      8. 7.5.8 Multi-Read and Multi-Write
    6. 7.6 Register Maps
      1. 7.6.1 I2C Registers
        1. 7.6.1.1  Battery Voltage Regulation Limit Register (Address = 0h) [reset = AAh]
          1. Table 5. REG00 Register Field Descriptions
        2. 7.6.1.2  Charger Current Limit Register (Address = 1h) [reset = 46h]
          1. Table 6. REG01 Register Field Descriptions
        3. 7.6.1.3  Input Voltage Limit Register (Address = 2h) [reset = 04h]
          1. Table 7. REG02 Register Field Descriptions
        4. 7.6.1.4  Input Current Limit Register (Address = 3h) [reset = 13h]
          1. Table 8. REG03 Register Field Descriptions
        5. 7.6.1.5  Reserved Register (Address = 4h) [reset = 03h]
          1. Table 9. REG04 Register Field Descriptions
        6. 7.6.1.6  Charger Control 1 Register (Address = 5h) [reset = 9Dh]
          1. Table 10. REG05 Register Field Descriptions
        7. 7.6.1.7  Charger Control 2 Register (Address = 6h) [reset = 33h]
          1. Table 11. REG06 Register Field Descriptions
        8. 7.6.1.8  INT Status Register (Address = 7h) [reset = X]
          1. Table 12. REG07 Register Field Descriptions
        9. 7.6.1.9  FAULT Status Register (Address = 8h) [reset = X]
          1. Table 13. REG08 Register Field Descriptions
        10. 7.6.1.10 INT Flag Status Register (Address = 9h) [reset = 00h]
          1. Table 14. REG09 Register Field Descriptions
        11. 7.6.1.11 FAULT Flag Register (Address = Ah) [reset = 00h]
          1. Table 15. REG0A Register Field Descriptions
        12. 7.6.1.12 INT Mask Register (Address = Bh) [reset = 00h]
          1. Table 16. REG0h Register Field Descriptions
        13. 7.6.1.13 FAULT Mask Register (Address = Ch) [reset = 00h]
          1. Table 17. REG0C Register Field Descriptions
        14. 7.6.1.14 Part Information Register (Address = Dh) [reset = 0Ah]
          1. Table 18. REG0D Register Field Descriptions
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 External Passive Recommendation
        2. 8.2.2.2 Inductor Selection
        3. 8.2.2.3 Input Capacitor
        4. 8.2.2.4 Flying Capacitor
        5. 8.2.2.5 Output Capacitor
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
        1. 11.1.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

7.4.1 Lossless Current Sensing

In high current charging systems, extra resistance between the charger output and the battery contribute to power loss and temperature rise. The BQ25910 regulates the output current without the need of a sense resistor, thereby reducing system power loss and operating temperature. Switching FET current information is used in conjunction to inductor DCR sensing to regulate output current accurately. For optimal operation, the voltage drop across the DCR should be below 180 mV. For example, to achieve 6-A charging, the DCR should be below 30 mΩ. In addition to lossless current regulation, the switching FET current is monitored on a cycle-by-cycle basis to ensure safe operation.