SLUSBC8C December   2013  – July 2018

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Wireless Power Consortium (WPC or Qi) Inductive Power System
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 A Brief Description of the Wireless System
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Details of a Qi Wireless Power System and bq51003 Power Transfer Flow Diagrams
      2. 8.3.2  Dynamic Rectifier Control
      3. 8.3.3  Dynamic Efficiency Scaling
      4. 8.3.4  RILIM Calculations
      5. 8.3.5  Input Overvoltage
      6. 8.3.6  Adapter Enable Functionality and EN1/EN2 Control
      7. 8.3.7  End Power Transfer Packet (WPC Header 0x02)
      8. 8.3.8  Status Outputs
      9. 8.3.9  WPC Communication Scheme
      10. 8.3.10 Communication Modulator
      11. 8.3.11 Adaptive Communication Limit
      12. 8.3.12 Synchronous Rectification
      13. 8.3.13 Temperature Sense Resistor Network (TS)
      14. 8.3.14 3-State Driver Recommendations for the TS-CTRL Pin
      15. 8.3.15 Thermal Protection
      16. 8.3.16 WPC v1.2 Compliance – Foreign Object Detection
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 bq51003 Wireless Power Receiver Used as a Power Supply
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Using the bq51003 as a Wireless Power Supply
          2. 9.2.1.2.2 Series and Parallel Resonant Capacitor Selection
          3. 9.2.1.2.3 COMM, CLAMP, and BOOT Capacitors
          4. 9.2.1.2.4 Control Pins and CHG
          5. 9.2.1.2.5 Current Limit and FOD
          6. 9.2.1.2.6 RECT and OUT Capacitance
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Dual Power Path: Wireless Power and DC Input
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
        3. 9.2.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    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

9.2.1.2.5 Current Limit and FOD

The current limit and foreign object detection functions are related. The current limit is set by R1 + RFOD. RFOD and Ros are determined by FOD calibration. Default values of 20 kΩ for Ros1 (RECT to FOD). Ros2 (OUT to FOD) remains open. 196 Ω for RFOD is used. The final values need to be determined based on the FOD calibration. The tool for FOD calibration can be found on the bq51003 web folder under Tools & software. Good practice is to set the layout with 2 resistors for Ros and 2 for RFOD to allow for precise values once the calibration is complete.

After setting RFOD, R1 can be calculated based on the desired current limit. The maximum current for this solution under normal operating conditions (IMAX) is 500 mA. Using Equation 2 to calculate the maximum current yields a value of 524 Ω for RILIM. With RFOD set to 196 Ω the remaining resistance for R1 is 328 Ω. This also sets the hardware current limit to 600 mA to allow for temporary current surges without system performance concerns.