SLUSDK0A August   2020  – March 2021 BQ25171-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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
  7. 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 CHM_TMR Pin Detection
        3. 7.3.1.3 VSET Pin Detection
        4. 7.3.1.4 Charger Power Up
      2. 7.3.2 Battery Charging Features
        1. 7.3.2.1 Lithium-Ion Battery Charging Profile
          1. 7.3.2.1.1 NiMH Battery Charging Profile
        2. 7.3.2.2 Charge Termination and Battery Recharge
        3. 7.3.2.3 Charging Safety Timers
        4. 7.3.2.4 Battery Cold, Hot Temperature Qualification (TS Pin)
      3. 7.3.3 Status Outputs (STAT1, STAT2)
        1. 7.3.3.1 Charging Status Indicator (STAT1, STAT2)
      4. 7.3.4 Protection Features
        1. 7.3.4.1 Input Overvoltage Protection (VIN OVP)
        2. 7.3.4.2 Output Overvoltage Protection (BAT OVP)
        3. 7.3.4.3 Output Overcurrent Protection (BAT 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
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1s LiFePO4 Charger Design Example
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Program the Fast Charge Current, ISET:
          2. 8.2.1.2.2 TS Function
        3. 8.2.1.3 Application Curves
      2. 8.2.2 2s Li-Ion Charger with Power Path Design Example
        1. 8.2.2.1 Design Requirements
      3. 8.2.3 4s NiMH Charger Design Example
        1. 8.2.3.1 Design Requirements
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 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
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.4.4 Thermal Regulation and Thermal Shutdown (TREG and TSHUT)

The device monitors its internal junction temperature (TJ) to avoid overheating and to limit the IC surface temperature. When the internal junction temperature exceeds the thermal regulation limit, the device automatically reduces the charge current to maintain the junction temperature at the thermal regulation limit (TREG). During thermal regulation, the actual charging current is usually below the programmed value on the ISET pin. Therefore, the termination comparator for the Lithium-Ion battery is disabled, and the safety timer runs at half the clock rate.

Additionally, the device has thermal shutdown to turn off the linear regulator when the IC junction temperature exceeds the TSHUT threshold. A recoverable fault is signaled via the status pins (STAT1 = LOW, STAT2 = HIGH). The charger resumes operation when the IC die temperature decreases below the TSHUT falling threshold.

GUID-20210308-CA0I-LL5X-QF8C-M0KXPKMXR0F0-low.svg Figure 7-8 Typical Charge Current Capability vs Ambient Temperature