SLUS756D September   2007  – June 2026 BQ24751A

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
    1. 4.1 Terminal Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 Recommended Operating Conditions
    3. 5.3 Package Thermal Data
    4. 5.4 Electrical Characteristics
    5. 5.5 Typical Charateristics
  7. 6 Detailed Description
    1. 6.1  Functional Block Diagram
    2. 6.2  Battery Voltage Regulation
    3. 6.3  Battery Current Regulation
    4. 6.4  Input Adapter Current Regulation
    5. 6.5  Adapter Detect and Power Up
    6. 6.6  Enable and Disable Charging
    7. 6.7  System Power Selector
    8. 6.8  Battery Learn Cycles
    9. 6.9  Automatic Internal Soft-Start Charger Current
    10. 6.10 Converter Operation
    11. 6.11 Synchronous and Non-Synchronous Operation
    12. 6.12 High Accuracy IADAPT Using Current Sense Amplifier (CSA)
    13. 6.13 Input Overvoltage Protection (ACOV)
    14. 6.14 Input Undervoltage Lock Out (UVLO)
    15. 6.15 Battery Overvoltage Protection
    16. 6.16 Battery Shorted (Battery Undervoltage) Protection
    17. 6.17 Charge Overcurrent Protection
    18. 6.18 Thermal Shutdown Protection
    19. 6.19 Adapter Detected Status Register ( ACGOOD Pin)
    20. 6.20 Input Over-Power Protection (ACOP)
      1. 6.20.1 Conditions for ACOP Latch Off:
  8. 7 Application Information
    1. 7.1 Input Capacitance Calculation
    2. 7.2 PCB Layout Design Guideline
  9. 8 Device and Documentation Support
    1. 8.1 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.8 Battery Learn Cycles

A battery Learn cycle can be implemented using the LEARN pin. A logic low on LEARN keeps the system power selector logic in its default states dependant on the adapter. If adapter is not detected, then; the ACFET is kept off, and the BATFET is kept on. If the adapter is detected, the BATFET is kept off, and the ACFET is kept on.

When the LEARN pin is at logic high, the system power selector logic is overridden, keeping the ACFET off and the BATFET on when the adapter is present. This is used to allow the battery to discharge in order to calibrate the battery gas gauge over a complete discharge/charge cycle. Charge turns off when LEARN is high. The controller automatically exits the learn cycle when BAT < 2.9 V per cell. BATDRV turns off and ACDRV turns on.