SLUSDO8A March   2020  – January 2025 BQ24800

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 Timing Requirements
    7. 5.7 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Device Power Up
        1. 6.3.1.1 Battery Only
        2. 6.3.1.2 Adapter Detect and ACOK Output
          1. 6.3.1.2.1 Adapter Overvoltage (ACOV)
        3. 6.3.1.3 REGN LDO
      2. 6.3.2 System Power Selection
      3. 6.3.3 Current and Power Monitor
        1. 6.3.3.1 High Accuracy Current Sense Amplifier (IADP and IDCHG)
        2. 6.3.3.2 High Accuracy Power Sense Amplifier (PMON)
      4. 6.3.4 Processor Hot Indication for CPU Throttling
      5. 6.3.5 Input Current Dynamic Power Management
        1. 6.3.5.1 Setting Input Current Limit
      6. 6.3.6 Two-Level Adapter Current Limit (Peak Power Mode)
      7. 6.3.7 EMI Switching Frequency Adjust
      8. 6.3.8 Device Protections Features
        1. 6.3.8.1 Charger Timeout
        2. 6.3.8.2 Input Overcurrent Protection (ACOC)
        3. 6.3.8.3 Charge Overcurrent Protection (CHG_OCP)
        4. 6.3.8.4 Battery Overvoltage Protection (BATOVP)
        5. 6.3.8.5 Battery Short
        6. 6.3.8.6 Thermal Shutdown Protection (TSHUT)
        7. 6.3.8.7 Inductor Short, MOSFET Short Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Battery Charging in Buck Mode
        1. 6.4.1.1 Setting the Charge Current
        2. 6.4.1.2 Setting the Charge Voltage
        3. 6.4.1.3 Automatic Internal Soft-Start Charger Current
      2. 6.4.2 Hybrid Power Boost Mode
      3. 6.4.3 Battery Only Boost Mode
        1. 6.4.3.1 Setting Minimum System Voltage in Battery Only Boost Mode
      4. 6.4.4 Battery Discharge Current Regulation in Hybrid Boost Mode and Battery Only Boost Mode
      5. 6.4.5 Battery LEARN Cycle
      6. 6.4.6 Converter Operational Modes
        1. 6.4.6.1 Continuous Conduction Mode (CCM)
        2. 6.4.6.2 Discontinuous Conduction Mode (DCM)
        3. 6.4.6.3 Non-Sync Mode and Light Load Comparator
    5. 6.5 Programming
      1. 6.5.1 SMBus Interface
        1. 6.5.1.1 SMBus Write-Word and Read-Word Protocols
        2. 6.5.1.2 Timing Diagrams
    6. 6.6 Register Maps
      1. 6.6.1  Battery-Charger Commands
      2. 6.6.2  Setting Charger Options
        1. 6.6.2.1 ChargeOption0 Register
      3. 6.6.3  ChargeOption1 Register
      4. 6.6.4  ChargeOption2 Register
      5. 6.6.5  ChargeOption3 Register
      6. 6.6.6  ProchotOption0 Register
      7. 6.6.7  ProchotOption1 Register
      8. 6.6.8  ProchotStatus Register
      9. 6.6.9  Charge Current Register
      10. 6.6.10 Charge Voltage Register
      11. 6.6.11 Discharge Current Register
      12. 6.6.12 Minimum System Voltage Register
      13. 6.6.13 Input Current Register
      14. 6.6.14 Register Exceptions
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Typical System Schematic
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1  Adapter Current Sense Filter
          2. 7.2.1.2.2  Negative Output Voltage Protection
          3. 7.2.1.2.3  Reverse Input Voltage Protection
          4. 7.2.1.2.4  Reduce Battery Quiescent Current
          5. 7.2.1.2.5  CIN Capacitance
          6. 7.2.1.2.6  L1 Inductor Selection
          7. 7.2.1.2.7  CBATT Capacitance
          8. 7.2.1.2.8  Buck Charging Internal Compensation
          9. 7.2.1.2.9  CSYS Capacitance
          10. 7.2.1.2.10 Battery Only Boost Internal Compensation
          11. 7.2.1.2.11 Power MOSFETs Selection
          12. 7.2.1.2.12 Input Filter Design
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Migration from Previous Devices (Does not Support Battery Only Boost)
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 CSYS Capacitance
        3. 7.2.2.3 Application Curves
  9. 8 Power Supply Recommendations
  10. 9 Layout
    1. 9.1 Layout Guidelines
    2. 9.2 Layout Examples
      1. 9.2.1 Layout Consideration of Current Path
      2. 9.2.2 Layout Consideration of Short Circuit Protection
      3. 9.2.3 Layout Consideration for Short Circuit Protection
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Documentation Support
      1. 10.2.1 Related Documentation
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

6.4.2 Hybrid Power Boost Mode

The BQ24800 device supports the hybrid power boost mode to boost battery voltage to adapter level and supplement adapter power when system power demand is temporarily higher than adapter maximum level. Ultra fast 150 µs response time (requires REG0x37[4:3] = 10b) keeps the adapter from crashing. After device powers up, the REG0x37[2] is 0 to disable hybrid power boost mode. To enable hybrid power boost mode, host writes 1 to REG0x37[2]. The BST_STAT pin and REG0x37[1] indicate if the device is in hybrid power boost mode when 0x37[11] = 1.

To support hybrid power boost mode, input current must be set higher than 1536 mA for 10-mΩ input current sensing resistor. The threshold to enter hybrid power boost mode (FDPM_RISE in REG0x37[5]) is set as percentage to the input current limit. When peak power is not enabled, the input current limit is always ILIM1, set in REG0x3F(). For discussion of hybrid boost behavior when peak power is enabled, refer to Section 6.3.6. When input current is higher than 104/107% of input current limit, the BQ24800 converter changes from buck charging converter to hybrid power boost converter. During hybrid power boost mode the adapter current is regulated at input current limit level so that adapter will not crash. If the watchdog timer is enabled (REG0x12[14:13]) and it expires, it will halt the hybrid boost mode converter. Writing to REG0x12[14:13], REG0x14 or REG0x15 will restart the watchdog timer and allow hybrid boost mode to be reentered.

One of the following conditions stops on-going hybrid power boost mode:

  • Adapter current falls below FDPM_FALL (REG0x37[0]) threshold
  • Hybrid power boost mode is disabled (REG0x37[2] = 0)
  • Adapter is removed
  • Battery voltage is below depletion threshold in REG0x3B[15:14]
  • ACFET turns off
  • TSHUT IC temperature threshold is reached
  • Short circuit is detected (see Inductor Short, MOSFET Short Protection for details)
  • Watchdog timer expires if watchdog timer is enabled (see Charger Timeout for details)