SLUS940D September   2009  – May 2021 BQ24050 , BQ24052

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 (1)
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions (1)
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 Typical Characteristics
      1. 6.8.1 Power Up, Down, OVP, Disable and Enable Waveforms
      2. 6.8.2 Protection Circuits Waveforms
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Power Down, or Undervoltage Lockout (UVLO)
      2. 7.3.2  Power Up
      3. 7.3.3  D+, D– Detection
      4. 7.3.4  New Charge Cycle
      5. 7.3.5  Overvoltage Protection (OVP) – Continuously Monitored
      6. 7.3.6  CHG Pin Indication
      7. 7.3.7  CHG LED Pullup Source
      8. 7.3.8  Input DPM Mode (VIN-DPM or IN-DPM)
      9. 7.3.9  OUT
      10. 7.3.10 ISET
      11. 7.3.11 TS
      12. 7.3.12 Termination and Timer Disable Mode (TTDM) -TS Pin High
      13. 7.3.13 Timers
      14. 7.3.14 Termination
      15. 7.3.15 Battery Detect Routine
      16. 7.3.16 Refresh Threshold
      17. 7.3.17 Starting a Charge on a Full Battery
    4. 7.4 Device Functional Modes
      1. 7.4.1 Sleep Mode
    5. 7.5 Programming
      1. 7.5.1 PRE_TERM – Precharge and Termination Programmable Threshold
      2. 7.5.2 ISET2
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 BQ2405x Charger Application 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 Program the Termination Current Threshold, ITERM
          3. 8.2.1.2.3 TS Function
          4. 8.2.1.2.4 CHG
          5. 8.2.1.2.5 Selecting IN and OUT Pin Capacitors
        3. 8.2.1.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
      1. 10.3.1 Leakage Current Effects on Battery Capacity
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary

7.3.11 TS

The TS pin is designed to follow the new JEITA temperature standard for Li-Ion and Li-Pol batteries. There are now four thresholds, 60°C, 45°C, 10°C, and 0°C. Normal operation occurs from 10°C to 45°C. If between 0°C and 10°C the charge current level is cut in half and if between 45°C and 60°C the regulation voltage is reduced to 4.1 Vmax, see Figure 7-4. The TS feature is implemented using an internal 50-μA current source to bias the thermistor (BQ24050 designed for use with a 10k NTC β = 3370 (SEMITEC 103AT-2 or Mitsubishi TH05-3H103F), and BQ24052 with a 100k NTC β = 3540 (Mitsubishi TH05-36104F) or equivalent) connected from the TS pin to VSS. If this feature is not needed, a fixed 10k can be placed between TS and VSS to allow normal operation. This may be done if the host is monitoring the thermistor and then the host would determine when to pull the TS pin low to disable charge.

The TS pin has two additional features, when the TS pin is pulled low or floated/driven high. A low disables charge (similar to a CE feature) and a high puts the charger in TTDM.

Above 60°C or below 0°C the charge is disable. Once the thermistor reaches ≉–10°C the TS current folds back to keep a cold thermistor (from –10°C to –50°C) from placing the IC in the TTDM mode. If the TS pin is pulled low into disable mode, the current is reduce to ≉30 μA, see Figure 7-2. Because the ITS current is fixed along with the temperature thresholds, it is not possible to use thermistor values other than the 10k and 100k.