SLUSF65A October   2023  – January 2026 BQ25185

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Thermal Information
    4. 6.4 Recommended Operating Conditions
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
      1. 7.1.1 Battery Charging Process
        1. 7.1.1.1 Trickle Charge
        2. 7.1.1.2 Precharge
        3. 7.1.1.3 Fast Charge
        4. 7.1.1.4 ISET Pin Detection
        5. 7.1.1.5 Termination
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Input Voltage Based Dynamic Power Management (VINDPM)
      2. 7.3.2  Dynamic Power Path Management Mode (DPPM)
      3. 7.3.3  Battery Supplement Mode
      4. 7.3.4  Sleep Mode
      5. 7.3.5  SYS Regulation
      6. 7.3.6  ILIM/VSET Control
      7. 7.3.7  Protection Mechanisms
        1. 7.3.7.1 Input Overvoltage Protection
        2. 7.3.7.2 Battery Undervoltage Lockout
        3. 7.3.7.3 Battery Overcurrent Protection
        4. 7.3.7.4 System Overvoltage Protection
        5. 7.3.7.5 System Short Protection
        6. 7.3.7.6 Thermal Protection and Thermal Regulation
        7. 7.3.7.7 Safety Timer
      8. 7.3.8  Pushbutton Long Press Function
      9. 7.3.9  External NTC Monitoring (TS)
        1. 7.3.9.1 TS Biasing and Function
      10. 7.3.10 Status Pins
    4. 7.4 Device Functional Modes
  9. 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 Input Current and Battery Regulation Voltage - ILIM/VSET
        2. 8.2.2.2 Fast Charge Current- ISET
        3. 8.2.2.3 Recommended Passive Components
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.1.1.4 ISET Pin Detection

After a valid VIN is applied and the CE pin is pulled LOW, the device checks the resistor on the ISET pin for a short circuit (RISET < RISET_SHORT). If a short is detected, the charger remains in the fault state until VIN or the CE pin is toggled. If the ISET pin is an open circuit, the charger charges with a very low charging current on the order of 1.5mA. This pin is monitored during charging, and changes in RISET while charging immediately affect the charge current. An external pull-down resistor (±1% or better recommended to minimize charge current error) from the ISET pin to GND sets the charge current as:

Equation 1. ICHG = (KISET) / (RISET)
  • ICHG is the desired fast charge current
  • KISET is a gain factor found in the Electrical Characteristics table (typically 300AΩ)
  • RISET is the pull-down resistor from the ISET pin to GND

For charge currents below 50mA, an extra RC circuit using 50pF capacitance is recommended on the ISET pin to improve signal stability. The ISET pin can also be used to monitor device current when the device is not in ICHG regulation. The voltage on the ISET pin is proportional to the charging current. To measure the charge current while charging, the following formula can be used:

Equation 2. ICHG = (KISET VISET) / (RISET)
  • VISET is the measured voltage on the ISET pin in volts
  • ICHG is the calculated charge current