SLUS941F September 2009  – March 2015


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information
    5. 7.5Electrical Characteristics
    6. 7.6Timing Requirements
    7. 7.7Typical Operational Characteristics (Protection Circuits Waveforms)
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
      1. 8.3.1Power-Down or Undervoltage Lockout (UVLO)
      2. 8.3.2Power-up
      3. 8.3.3Sleep Mode
      4. 8.3.4New Charge Cycle
      5. 8.3.5Overvoltage-Protection (OVP) - Continuously Monitored
      6. 8.3.6Power Good Indication (PG)
      7. 8.3.7 CHG Terminal Indication
    4. 8.4Device Functional Modes
      1. 8.4.1  CHG and PG LED Pull-up Source
      2. 8.4.2 Auto Start-up (bq24041)
      3. 8.4.3 IN-DPM (VIN-DPM or IN-DPM)
      4. 8.4.4 OUT
      5. 8.4.5 ISET
      6. 8.4.6 PRE_TERM - Pre-Charge and Termination Programmable Threshold, bq24040/5
      7. 8.4.7 ISET2
      8. 8.4.8 TS (bq24040/5)
      9. 8.4.9 Termination and Timer Disable Mode (TTDM) - TS Terminal High
      10. 8.4.10Timers, bq24040 and bq24045 only
      11. 8.4.11Termination
      12. 8.4.12Battery Detect Routine
      13. 8.4.13Refresh Threshold
      14. 8.4.14Starting a Charge on a Full Battery
  9. Application and Implementation
    1. 9.1Application Information
    2. 9.2Typical Applications
      1. 9.2.1Typical Application: bq24040 and bq24045
        1. Requirements
        2. Design Procedures
            1. the Fast Charge Current, ISET:
            2. the Termination Current Threshold, ITERM:
            3. Function (bq24040)
            4. CHG and PG
          2. In and Out Terminal Capacitors
          3. Package
            1. Current Effects on Battery Capacity
        3. Performance Curves
      2. 9.2.2Typical Application Circuit: bq24041, with ASI and ASO
        1. Requirements
        2. Design Procedures
        3. Performance Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
  12. 12Device and Documentation Support
    1. 12.1Documentation Support
    2. 12.2Related Links
    3. 12.3Trademarks
    4. 12.4Electrostatic Discharge Caution
    5. 12.5Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information

1 Features

  • Charging
    • 1% Charge Voltage Accuracy
    • 10% Charge Current Accuracy
    • Pin Selectable USB 100mA and 500mA Maximum Input Current Limit
    • Programmable Termination and Precharge Threshold, bq24040 and bq24045
    • High voltage (4.35V) Chemistry Support with bq24045
  • Protection
    • 30V Input Rating; with 6.6V or 7.1V Input Overvoltage Protection
    • Input Voltage Dynamic Power Management
    • 125°C Thermal Regulation; 150°C Thermal Shutdown Protection
    • OUT Short-Circuit Protection and ISET short detection
    • Operation over JEITA Range via Battery NTC – 1/2 Fast-Charge-Current at Cold, 4.06V at Hot, bq24040 and bq24045
    • Fixed 10 Hour Safety Timer, bq24040 and bq24045
  • System
    • Automatic Termination and Timer Disable Mode (TTDM) for Absent Battery Pack With Thermistor, bq24040 and bq24045
    • Status Indication – Charging/Done
    • Available in Small 2×2mm2 DFN-10 Package
    • Integrated Auto Start Function for Production Line Testing, bq24041

2 Applications

  • Smart Phones
  • PDAs
  • MP3 Players
  • Low-Power Handheld Devices

3 Description

The bq2404x series of devices are highly integrated Li-Ion and Li-Pol linear chargers devices targeted at space-limited portable applications. The devices operate from either a USB port or AC adapter. The high input voltage range with input overvoltage protection supports low-cost unregulated adapters.

The bq2404x has a single power output that charges the battery. A system load can be placed in parallel with the battery as long as the average system load does not keep the battery from charging fully during the 10 hour safety timer.

The battery is charged in three phases: conditioning, constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if an internal temperature threshold is exceeded.

The charger power stage and charge current sense functions are fully integrated. The charger function has high accuracy current and voltage regulation loops, charge status display, and charge termination. The pre-charge current and termination current threshold are programmed via an external resistor on the bq24040 and bq24045. The fast charge current value is also programmable via an external resistor.

Device Information(1)

bq24040WSON (10)2.00 mm x 2.00 mm
bq24041WSON (10)2.00 mm x 2.00 mm
bq24045WSON (10)2.00 mm x 2.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Schematic

bq24040 bq24041 bq24045 app_cir_lus941.gif

4 Revision History

Changes from E Revision (February 2014) to F Revision

Changes from D Revision (March 2013) to E Revision

  • Added Handling Ratings table , Feature Description section, Device Functional Modes section, Application and Implementation section, Power Supply Recommendations section, Layout section, Device and Documentation Support section, and Mechanical, Packaging, and Orderable Information sectionGo
  • Changed the Dissipation Rating table to the Thermal Information.Go
  • Changed VO_HT(REG) in the Electrical Characteristics table to include new values bq24045Go
  • Added the Timing Requirements tableGo
  • Deleted the last sentence in the first paragraph of the TS (bq24040/5) section Go
  • Added the Application Performance CurvesGo

Changes from C Revision (February 2013) to D Revision

  • Changed Feature From: Fixed 10 Hour Safety Timer To: Fixed 10 Hour Safety Timer, bq24040 and bq24045Go
  • Changed the OUT terminal DESCRIPTIONGo
  • Changed RISET NOM value in the ROC table From: 49.9 kΩ To: 10.8 kΩGo
  • Changed RISET_SHORT test conditions From: RISET : 600Ω → 250Ω To: RISET : 540Ω → 250ΩGo
  • Changed IOUT_CL test conditions From: RISET : 600Ω → 250Ω To: RISET : 540Ω → 250ΩGo
  • Deleted: Internally Set: bq24041 from the TERMINATION sectionGo
  • Added bq24040 and bq24045 only to the BATTERY CHARGING TIMERS AND FAULT TIMERS sectionGo
  • Changed text in the ISET section From: "maximum current between 1.1A and 1.35A" To: "maximum current between 1.05A and 1.4A"Go
  • Changed the Timers sectionGo
  • Deleted: IOUT_TERM = 54mA from the Typical Application Circuit: bq24041, with ASI and ASO conditionsGo

Changes from B Revision (June 2012) to C Revision

  • Added device bq24045Go
  • Added additional KISET information to the Electrical Characteristics tableGo
  • Added graph - Load RegulationGo
  • Added graph - Line RegulationGo

Changes from A Revision (September 2009) to B Revision

  • Changed all occurrences of Li-Ion To: Li-Ion and Li-PolGo

Changes from * Revision (August 2009) to A Revision

  • Changed the status of the devices From: Product Preview To: Production DataGo