SLUSF72 October   2023 BQ25176J

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Device Power Up from Input Source
        1. 7.3.1.1 ISET Pin Detection
        2. 7.3.1.2 VSET Pin Detection
        3. 7.3.1.3 Charger Power Up
      2. 7.3.2 Battery Charging Features
        1. 7.3.2.1 Lithium-Ion Battery Charging Profile
        2. 7.3.2.2 Input Voltage Based Dynamic Power Management (VINDPM)
        3. 7.3.2.3 Charge Termination and Battery Recharge
        4. 7.3.2.4 Charging Safety Timers
        5. 7.3.2.5 Battery Temperature Qualification (TS Pin)
      3. 7.3.3 Status Outputs ( PG, STAT)
        1. 7.3.3.1 Power Good Indicator (PG Pin)
        2. 7.3.3.2 Charging Status Indicator (STAT)
      4. 7.3.4 Protection Features
        1. 7.3.4.1 Input Overvoltage Protection (VIN_OV)
        2. 7.3.4.2 Output Overvoltage Protection (VOUT_OVP)
        3. 7.3.4.3 Output Overcurrent Protection (IOUT_OCP)
        4. 7.3.4.4 Thermal Regulation and Thermal Shutdown (TREG and TSHUT)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown or Undervoltage Lockout (UVLO)
      2. 7.4.2 Sleep Mode
      3. 7.4.3 Active Mode
        1. 7.4.3.1 Standby Mode
      4. 7.4.4 Fault Mode
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Li-Ion Charger Design Example
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curves
  10. 9 Power Supply Recommendations
  11. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2.4 Charging Safety Timers

The device has built-in safety timers to prevent an extended charging cycle due to abnormal battery conditions. The precharge timer is fixed at 30 minutes. The fast-charge safety timer is fixed at 10 hours. When the safety timer expires, the charge cycle ends. A toggle on the input supply or TS pin is required to restart a charge cycle after the safety timer has expired.

During thermal regulation or VINDPM, the safety timer counts at half the clock rate as the actual charge current is likely to be below the ISET setting. For example, if the charger is in thermal regulation throughout the whole charging cycle and the safety timer is 10 hours, then the timer will expire in 20 hours.

During faults which disable charging, such as VIN_OV, VOUT_OVP, TSHUT, or TS faults, the timer is suspended. Once the fault goes away, charging and the safety timer resume. If the charging cycle is stopped and started again, the timer gets reset (toggle of the TS pin restarts the timer).

The safety timer restarts counting for the following events:

  1. Charging cycle stop and restart (toggle TS pin, charged battery falls below recharge threshold, or toggle input supply)
  2. OUT pin voltage crosses the VBAT_LOWV threshold in either direction

The precharge safety timer (fixed counter that runs when VOUT < VBAT_LOWV), follows the same rules as the fast-charge safety timer in terms of getting suspended, reset, and counting at half-rate.