SLUSBA1H October   2012  – August 2015 BQ24250 , BQ24251 , BQ24253

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Options
  7. 7 Pin Configuration and 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  Charge Profile
      2. 9.3.2  EN1 and EN2 Pins
      3. 9.3.3  External Settings: ISET, ILIM and VIN_DPM
      4. 9.3.4  BC1.2 D+/D- Detection
      5. 9.3.5  Transient Response
      6. 9.3.6  AnyBoot Battery Detection
      7. 9.3.7  Input Voltage Based DPM
      8. 9.3.8  Sleep Mode
      9. 9.3.9  Input Over-Voltage Protection
      10. 9.3.10 NTC Monitor
      11. 9.3.11 Production Test Mode
      12. 9.3.12 Safety Timer
      13. 9.3.13 Watchdog Timer
      14. 9.3.14 Fault Modes
      15. 9.3.15 Dynamic Power Path Management
    4. 9.4 Device Functional Modes
      1. 9.4.1 I2C Operation (Host Mode / Default Mode)
    5. 9.5 Programming
      1. 9.5.1 Serial Interface Description
        1. 9.5.1.1 F/S Mode Protocol
    6. 9.6 Register Maps
      1. 9.6.1 Register #1
      2. 9.6.2 Register #2
      3. 9.6.3 Register #3
      4. 9.6.4 Register #4
      5. 9.6.5 Register #5
      6. 9.6.6 Register #6
      7. 9.6.7 Register #7
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Inductor Selection
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
    3. 12.3 Thermal Considerations
  13. 13Device and Documentation Support
    1. 13.1 Related Links
    2. 13.2 Trademarks
    3. 13.3 Electrostatic Discharge Caution
    4. 13.4 Glossary
  14. 14Mechanical, Packaging, and Orderable Information
    1. 14.1 Package Summary

5 Description (continued)

The power-path management feature allows the bq24250, bq24251, and bq24253 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 reduced charge current allows for proper charge termination and enables the system to run with a defective or absent battery pack. Additionally, this reduced charge current enables instant system turnon even with a totally discharged battery or no battery. The architecture of the power-path management also permits the battery to supplement the system current requirements when the adapter cannot deliver the peak system currents. This supplementation of current requirements enables the use of a smaller adapter.

The battery is charged in four phases: trickle charge, precharge, 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, JEITA compatible battery pack thermistor monitoring input (TS) that monitors battery temperature for safe charging is included.