SLUSC59A April   2015  – December 2016

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (Continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD 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. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Device Power Up
        1. 8.3.1.1 Power-On-Reset (POR)
        2. 8.3.1.2 Power Up from Battery without DC Source
          1. 8.3.1.2.1 BATFET Turn Off
          2. 8.3.1.2.2 Shipping Mode
          3. 8.3.1.2.3 BATFET System Reset
        3. 8.3.1.3 Power Up from DC Source
          1. 8.3.1.3.1 REGN LDO
          2. 8.3.1.3.2 Input Source Qualification
          3. 8.3.1.3.3 Input Current Limit Detection
          4. 8.3.1.3.4 PSEL/OTG Pins Set Input Current Limit
          5. 8.3.1.3.5 HIZ State with 100mA USB Host
          6. 8.3.1.3.6 Force Input Current Limit Detection
        4. 8.3.1.4 Converter Power-Up
        5. 8.3.1.5 Boost Mode Operation from Battery
      2. 8.3.2 Power Path Management
        1. 8.3.2.1 Narrow VDC Architecture
        2. 8.3.2.2 Dynamic Power Management
        3. 8.3.2.3 Supplement Mode
      3. 8.3.3 Battery Charging Management
        1. 8.3.3.1 Autonomous Charging Cycle
        2. 8.3.3.2 Battery Charging Profile
        3. 8.3.3.3 Thermistor Qualification
          1. 8.3.3.3.1 Cold/Hot Temperature Window
        4. 8.3.3.4 Charging Termination
          1. 8.3.3.4.1 Termination When REG02[0] = 1
        5. 8.3.3.5 Charging Safety Timer
          1. 8.3.3.5.1 Safety Timer Configuration Change
        6. 8.3.3.6 USB Timer When Charging from USB100mA Source
      4. 8.3.4 Status Outputs (PG, STAT, and INT)
        1. 8.3.4.1 Power Good Indicator (PG) (bq24298)
        2. 8.3.4.2 Charging Status Indicator (STAT)
        3. 8.3.4.3 Interrupt to Host (INT)
      5. 8.3.5 Protections
        1. 8.3.5.1 Input Current Limit on ILIM
        2. 8.3.5.2 Thermal Regulation and Thermal Shutdown
        3. 8.3.5.3 Voltage and Current Monitoring in Buck Mode
          1. 8.3.5.3.1 Input Over-Voltage (ACOV)
          2. 8.3.5.3.2 System Over-Voltage Protection (SYSOVP)
        4. 8.3.5.4 Voltage and Current Monitoring in Boost Mode
          1. 8.3.5.4.1 Over-Current Protection
          2. 8.3.5.4.2 VBUS Over-Voltage Protection
          3. 8.3.5.4.3 Output Short Protection
        5. 8.3.5.5 Battery Protection
          1. 8.3.5.5.1 Battery Over-Voltage Protection (BATOVP)
          2. 8.3.5.5.2 Battery Short Protection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Host Mode and Default Mode
        1. 8.4.1.1 Plug in USB100mA Source with Good Battery
        2. 8.4.1.2 USB Timer When Charging from USB100mA Source
    5. 8.5 Programming
      1. 8.5.1 Serial Interface
        1. 8.5.1.1 Data Validity
        2. 8.5.1.2 START and STOP Conditions
        3. 8.5.1.3 Byte Format
        4. 8.5.1.4 Acknowledge (ACK) and Not Acknowledge (NACK)
        5. 8.5.1.5 Slave Address and Data Direction Bit
          1. 8.5.1.5.1 Single Read and Write
          2. 8.5.1.5.2 Multi-Read and Multi-Write
    6. 8.6 Register Map
      1. 8.6.1 I2C Registers
        1. 8.6.1.1  Input Source Control Register REG00 [reset = 00110xxx, or 3x]
        2. 8.6.1.2  Power-On Configuration Register REG01 [reset = 00011011, or 0x1B]
        3. 8.6.1.3  Charge Current Control Register REG02 [reset = 01100000, or 60]
        4. 8.6.1.4  Pre-Charge/Termination Current Control Register REG03 [reset = 00010001, or 0x11]
        5. 8.6.1.5  Charge Voltage Control Register REG04 [reset = 10110010, or 0xB2]
        6. 8.6.1.6  Charge Termination/Timer Control Register REG05 [reset = 11011100, or 0xDC]
        7. 8.6.1.7  Boost Voltage/Thermal Regulation Control Register REG06 [reset = 01110011, or 0x73]
        8. 8.6.1.8  Misc Operation Control Register REG07 [reset = 01001011, or 4B]
        9. 8.6.1.9  System Status Register REG08
        10. 8.6.1.10 New Fault Register REG09
        11. 8.6.1.11 Vender / Part / Revision Status Register REG0A
  9. 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
        2. 9.2.2.2 Input Capacitor
        3. 9.2.2.3 Output Capacitor
      3. 9.2.3 Application Performance Plots
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 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 I2C serial interface with charging and system settings makes the device a truly flexible solution.

The device supports 3.9V – 6.2V USB input sources, including standard USB host port and USB charging port with 6.4V over-voltage protection. The device supports USB 2.0 and USB 3.0 power specifications with input current and voltage regulation. To set the default input current limit, the bq24298 takes the result from the detection circuit in the system, such as USB PHY device. The device also supports USB On-the-Go operation by providing fast startup and supplying adjustable voltage 4.55 – 5.5V (default 5V) on the VBUS with an accurate current limit up to 1.5A.

The power path management regulates the system slightly above battery voltage but does not drop below 3.5V minimum system voltage (programmable). With this feature, the system keeps operating even when the battery is completely depleted or removed. When the input source current or voltage limit is reached, the power path management automatically reduces the charge current to zero and then starts discharges the battery until the system power requirement is met. This supplement mode operation keeps the input source from getting overloaded.

The device initiates and completes a charging cycle when host control is not available. It automatically charges the battery in three phases: pre-conditioning, constant current and constant voltage. In the end, the charger automatically terminates when the charge current is below a preset limit in the constant voltage phase. Later on, when the battery voltage falls below the recharge threshold, the charger will automatically start another charging cycle.

The charge device provides various safety features for battery charging and system operation, including negative thermistor monitoring, charging safety timer and over-voltage/over-current protections. The thermal regulation reduces charge current when the junction temperature exceeds 120°C (programmable).

The STAT output reports the charging status and any fault conditions. The INT immediately notifies host when fault occurs.

The bq24298 is available in a 24-pin, 4.00-mm x 4.00-mm thin WQFN package.