SLUSDL9A June   2019  – January 2021 BQ25125

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Ship Mode
        1. 9.3.1.1 Ship Mode Entry and Exit
      2. 9.3.2  High Impedance Mode
      3. 9.3.3  Active Battery Only Connected
      4. 9.3.4  Voltage Based Battery Monitor
      5. 9.3.5  Sleep Mode
      6. 9.3.6  Input Voltage Based Dynamic Power Management (VIN(DPM))
      7. 9.3.7  Input Overvoltage Protection and Undervoltage Status Indication
      8. 9.3.8  Battery Charging Process and Charge Profile
      9. 9.3.9  Battery Supplement Mode
      10. 9.3.10 Default Mode
      11. 9.3.11 Termination and Pre-Charge Current Programming by External Components (IPRETERM)
      12. 9.3.12 Input Current Limit Programming by External Components (ILIM)
      13. 9.3.13 Charge Current Programming by External Components (ISET)
      14. 9.3.14 Safety Timer
      15. 9.3.15 External NTC Monitoring (TS)
      16. 9.3.16 Thermal Protection
      17. 9.3.17 Typical Application Power Dissipation
      18. 9.3.18 Status Indicators ( PG and INT)
      19. 9.3.19 Chip Disable ( CD)
      20. 9.3.20 Buck (PWM) Output
      21. 9.3.21 Load Switch / LDO Output and Control
      22. 9.3.22 Manual Reset Timer and Reset Output ( MR and RESET)
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 Serial Interface Description
      2. 9.5.2 F/S Mode Protocol
    6. 9.6 Register Maps
      1. 9.6.1  Status and Ship Mode Control Register
      2. 9.6.2  Faults and Faults Mask Register
      3. 9.6.3  TS Control and Faults Masks Register
      4. 9.6.4  Fast Charge Control Register
      5. 9.6.5  Termination/Pre-Charge Register
      6. 9.6.6  Battery Voltage Control Register
      7. 9.6.7  SYS VOUT Control Register
      8. 9.6.8  Load Switch and LDO Control Register
      9. 9.6.9  Push-button Control Register
      10. 9.6.10 ILIM and Battery UVLO Control Register
      11. 9.6.11 Voltage Based Battery Monitor Register
      12. 9.6.12 VIN_DPM and Timers Register
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Default Settings
        2. 10.2.2.2 Choose the Correct Inductance and Capacitance
        3. 10.2.2.3 Calculations
          1. 10.2.2.3.1 Program the Fast Charge Current (ISET)
          2. 10.2.2.3.2 Program the Input Current Limit (ILIM)
          3. 10.2.2.3.3 Program the Pre-charge/termination Threshold (IPRETERM)
          4. 10.2.2.3.4 TS Resistors (TS)
      3. 10.2.3 Application Performance Curves
        1. 10.2.3.1 Charger Curves
        2. 10.2.3.2 SYS Output Curves
        3. 10.2.3.3 Load Switch and LDO Curves
        4. 10.2.3.4 LS/LDO Output Curves
        5. 10.2.3.5 Timing Waveforms Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.4 Voltage Based Battery Monitor

The device implements a simple voltage battery monitor which can be used to determine the depth of discharge. Prior to entering High-Z mode, the device will initiate a VBMON reading. The host can read the latched value for the no-load battery voltage, or initiate a reading using VBMON_READ to see the battery voltage under a known load. The register will be updated and can be read 2ms after a read is initiated. The VBMON voltage threshold is readable with 2% increments with ±1.5% accuracy between 60% and 100% of VBATREG using the VBMON_TH registers.  Reading the value during charge is possible, but for the most accurate battery voltage indication, it is recommended to disable charge, initiate a read, and then re-enable charge.

A typical discharge profile for a Li-Ion battery is shown in Table 9-2. The specific battery to be used in the application should be fully characterized to determine the thresholds that will indicate the appropriate battery status to the user. Two typical examples are shown below, assuming the VBMON reading is taken with no load on the battery.

This function enables a simple 5-bar status indicator with the following typical performance with different VBATREG settings:

Table 9-2 Discharge Profile for a Li-Ion Battery
VBATREGBATTERY FULL95% to 65%
REMAINING CAPACITY		65% to 35%
REMAINING CAPACITY		35% to 5%
REMAINING CAPACITY		BATTERY EMPTY
4.35 VVBMON > 90%VBMON = 88%VBMON = 86%VBMON = 84%VBMON < 82%
4.2 VVBMON > 98%VBMON = 94% or 96%VBMON = 90% or 92%VBMON = 86% or 88%VBMON < 84%
GUID-71BB67E5-3EAF-48C5-90CF-B7B9B39BAC15-low.gifFigure 9-3 Voltage Battery Monitor