SLUSG51 October   2025 BQ25692-Q1

ADVANCE INFORMATION  

  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-On-Reset
      2. 6.3.2  Battery Only Power Up State
      3. 6.3.3  Device HIZ State
      4. 6.3.4  Power Up REGN LDO
      5. 6.3.5  Default VINDPM Setting
      6. 6.3.6  Default Charge Profile Setting with CELL, ICHG and VCHG Pins
      7. 6.3.7  Buck-Boost Converter Operation
        1. 6.3.7.1 Pulse Frequency Modulation (PFM)
        2. 6.3.7.2 Switching Frequency and Dithering Feature
      8. 6.3.8  Forward (Sink) Operation
        1. 6.3.8.1 Power Path Management
          1. 6.3.8.1.1 Dynamic Power Management
            1. 6.3.8.1.1.1 ILIM_HIZ Pin
            2. 6.3.8.1.1.2 Input Current Optimizer (ICO)
        2. 6.3.8.2 Battery Charging Management
          1. 6.3.8.2.1 Battery Detection
          2. 6.3.8.2.2 Autonomous Charging Cycle
          3. 6.3.8.2.3 Battery Charging Profile
          4. 6.3.8.2.4 Charging Termination
          5. 6.3.8.2.5 Charging Safety Timer
          6. 6.3.8.2.6 CV Timer
          7. 6.3.8.2.7 Thermistor Qualification
            1. 6.3.8.2.7.1 JEITA Guideline Compliance in Charge Mode
            2. 6.3.8.2.7.2 Cold/Hot Temperature Window in Reverse Mode
        3. 6.3.8.3 Bypass Mode
      9. 6.3.9  Reverse (Source) Mode (USB On-The-Go)
        1. 6.3.9.1 Reverse (Source) Mode Operation
        2. 6.3.9.2 Backup Power Supply Mode
        3. 6.3.9.3 Reverse Bypass Mode
      10. 6.3.10 Status Outputs ( STAT, and INT)
        1. 6.3.10.1 Power Good Indicator (PG_STAT)
        2. 6.3.10.2 Charging Status Indicator (STAT Pin)
        3. 6.3.10.3 Interrupt to Host ( INT)
      11. 6.3.11 Serial Interface
        1. 6.3.11.1 Data Validity
        2. 6.3.11.2 START and STOP Conditions
        3. 6.3.11.3 Byte Format
        4. 6.3.11.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 6.3.11.5 Target Address and Data Direction Bit
        6. 6.3.11.6 Single Write and Read
        7. 6.3.11.7 Multi-Write and Multi-Read
    4. 6.4 Device Functional Modes
      1. 6.4.1 Host Mode and Default Mode
      2. 6.4.2 Register Bit Reset
    5. 6.5 Register Map
      1. 6.5.1 BQ25692Q1 Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application Design Example
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Inductor Selection
        2. 7.2.2.2 Capacitors
        3. 7.2.2.3 Buck Mode Input (VIN) Capacitor
        4. 7.2.2.4 Boost Mode Output (VOUT) Capacitor
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Package Option Addendum
    2. 10.2 Tape and Reel Information
    3. 10.3 Mechanical Data

6.4.1 Host Mode and Default Mode

The device is a host controlled charger, but it can operate in default mode without host management. In default mode, the device can be used as an autonomous charger with no host or while host is in sleep mode. When the charger is in default mode, WD_STAT bit becomes HIGH, WD_FLAG is set to 1, and an INT is asserted low to alert the host (unless masked by WD_MASK). The WD_FLAG bit would read as 1 upon the first read and then 0 upon subsequent reads. When the charger is in host mode, WD_STAT bit is LOW.

After power-on-reset, the device starts in default mode with watchdog timer expired. All the registers are in the default settings.

In default mode, the device keeps charging the battery with default charging safety timers. At the end of the safety timer expiration, the charging is stopped.

A write to any I2C register transitions the charger from default mode to host mode, and initiates the watchdog timer. All the device parameters can be programmed by the host. To keep the device in host mode, the host has to reset the watchdog timer by writing 1 to WD_RST bit before the watchdog timer expires (WD_STAT bit is set), or disable watchdog timer by setting WATCHDOG bits = 00.

When the watchdog timer is expired, the device returns to default mode and all registers are reset to default values except the ones described in the Register Map. The watchdog timer will be reset on any write if the watchdog timer has expired. When watchdog timer expires, WD_STAT and WD_FLAG is set to 1, and an INT is asserted low to alert the host (unless masked by WD_MASK).

BQ25692-Q1 Watchdog Timer Flow Chart Figure 6-20 Watchdog Timer Flow Chart