SLUSBY7 July   2014

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Description (Continued)
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Dynamic Power Path Management
      2. 8.3.2 Production Test Mode
      3. 8.3.3 AnyBoot Battery Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1  Charge Profile
      2. 8.4.2  EN1/EN2 Pins
      3. 8.4.3  I2C Operation (Host Mode / Default Mode)
      4. 8.4.4  External Settings: ISET, ILIM and VIN_DPM
      5. 8.4.5  Transient Response
      6. 8.4.6  Input Voltage Based DPM
      7. 8.4.7  Sleep Mode
      8. 8.4.8  Input Over-Voltage Protection
      9. 8.4.9  NTC Monitor
      10. 8.4.10 Safety Timer
      11. 8.4.11 Watchdog Timer
      12. 8.4.12 Thermal Regulation and Thermal Shutdown
      13. 8.4.13 Fault Modes
      14. 8.4.14 Serial Interface Description
        1. 8.4.14.1 F/S Mode Protocol
    5. 8.5 Register Maps
  9. Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Inductor Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Board Layout
    3. 11.3 Package Summary
  12. 12Device and Documentation Support
    1. 12.1 Trademarks
    2. 12.2 Electrostatic Discharge Caution
    3. 12.3 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

5 Description (Continued)

The power path management feature allows the bq24250C to power the system from a high efficiency DC/DC converter while simultaneously and independently charging the battery. The charger monitors the battery current at all times and reduces the charge current when the system load requires current above the input current limit. This allows for proper charge termination and enables the system to run with a defective or absent battery pack. Additionally, this enables instant system turn-on even with a totally discharged battery or no battery. The power-path management architecture also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents. This enables the use of a smaller adapter.

The battery is charged in four phases: trickle charge, pre-charge, constant current and constant voltage. In all charge phases, an internal control loop monitors the IC junction temperature and reduces the charge current if the internal temperature threshold is exceeded. Additionally, a voltage-based battery pack thermistor monitoring input (TS) is included that monitors battery temperature for safe charging.