SLUS892D December   2009  – December 2019 BQ24610 , BQ24617

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
    1.     Pin 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 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  Battery Voltage Regulation
      2. 9.3.2  Battery Current Regulation
      3. 9.3.3  Input Adapter Current Regulation
      4. 9.3.4  Precharge
      5. 9.3.5  Charge Termination, Recharge, and Safety Timer
      6. 9.3.6  Power Up
      7. 9.3.7  Enable and Disable Charging
      8. 9.3.8  System Power Selector
      9. 9.3.9  Automatic Internal Soft-Start Charger Current
      10. 9.3.10 Converter Operation
      11. 9.3.11 Synchronous and Nonsynchronous Operation
      12. 9.3.12 Cycle-by-Cycle Charge Undercurrent Protection
      13. 9.3.13 Input Overvoltage Protection (ACOV)
      14. 9.3.14 Input Undervoltage Lockout (UVLO)
      15. 9.3.15 Battery Overvoltage Protection
      16. 9.3.16 Cycle-by-Cycle Charge Overcurrent Protection
      17. 9.3.17 Thermal Shutdown Protection
      18. 9.3.18 Temperature Qualification
      19. 9.3.19 Timer Fault Recovery
      20. 9.3.20 PG Output
      21. 9.3.21 CE (Charge Enable)
      22. 9.3.22 Charge Status Outputs
      23. 9.3.23 Battery Detection
    4. 9.4 Device Functional Modes
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 System with Power Path
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedure
          1. 10.2.1.2.1 Inductor Selection
          2. 10.2.1.2.2 Input Capacitor
          3. 10.2.1.2.3 Output Capacitor
          4. 10.2.1.2.4 Power MOSFETs Selection
          5. 10.2.1.2.5 Input Filter Design
          6. 10.2.1.2.6 Inductor, Capacitor, and Sense Resistor Selection Guidelines
        3. 10.2.1.3 Application Curves
      2. 10.2.2 Simplified System without Power Path or DPM
        1. 10.2.2.1 Design Requirements
        2. 10.2.2.2 Detailed Design Procedure
        3. 10.2.2.3 Application Curves
      3. 10.2.3 Lead-Acid Charging System
        1. 10.2.3.1 Design Requirements
        2. 10.2.3.2 Detailed Design Procedure
        3. 10.2.3.3 Application 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 Related Links
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Support Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.18 Temperature Qualification

The controller continuously monitors battery temperature by measuring the voltage between the TS pin and GND. A negative temperature coefficient thermistor (NTC) and an external voltage divider typically develop this voltage. The controller compares this voltage against its internal thresholds to determine if charging is allowed. To initiate a charge cycle, the battery temperature must be within the VLTF to VHTF thresholds. If battery temperature is outside of this range, the controller suspends charge and the safety timer, and waits until the battery temperature is within the VLTF to VHTF range. During the charge cycle, the battery temperature must be within the VLTF to VTCO thresholds. If battery temperature is outside of this range, the controller suspends charge and waits until the battery temperature is within the VLTF to VHTF range. The controller suspends charge by turning off the PWM charge FETs. Figure 15 summarizes the operation.

BQ24610 BQ24617 tspin_lus892.gifFigure 15. TS Pin, Thermistor Sense Thresholds

Assuming a 103AT NTC thermistor on the battery pack as shown in Figure 20, the value RT1 and RT2 can be determined by using the following equations:

Equation 8. BQ24610 BQ24617 eq9_rt2a_lus892.gif
Equation 9. BQ24610 BQ24617 eq8_rt1_lus892.gif

For example, 103AT NTC thermistors are used to monitor the battery pack temperature. Select TCOLD = 0ºC and TCUT_OFF = 45ºC; then we get RT2 = 430 kΩ, RT1 = 9.31 kΩ. A small RC filter is suggested to use for system-level ESD protection.

BQ24610 BQ24617 tsres_lus892.gifFigure 16. TS Resistor Network