SLUSFU9 October   2024 BQ51013C

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (continued)
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Details of a Qi Wireless Power System and BQ51013C 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 v2.0 Compliance – Foreign Object Detection
      17. 8.3.17 Receiver Coil Load-Line Analysis
    4. 8.4 Device Functional Modes
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 BQ51013C 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 BQ51013C as a Wireless Power Supply: (See Figure 1-1 )
          2. 9.2.1.2.2 Series and Parallel Resonant Capacitor Selection
          3. 9.2.1.2.3 Recommended RX Coils
          4. 9.2.1.2.4 COMM, CLAMP, and BOOT Capacitors
          5. 9.2.1.2.5 Control Pins and CHG
          6. 9.2.1.2.6 Current Limit and FOD
          7. 9.2.1.2.7 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
      3. 9.2.3 Wireless and Direct Charging of a Li-Ion Battery at 800 mA
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
        3. 9.2.3.3 Application Curves
  11. 10Power Supply Recommendations
  12. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  13. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
      2. 12.1.2 Development Support
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  14. 13Revision History
  15. 14Mechanical, Packaging, and Orderable Information

9.2.2.2 Detailed Design Procedure

The components chosen for the Section 9.2.1 system are identical. Adding a blocking FET while using the BQ51013C for control is the only addition to the circuitry.The AD pin will be tied to the DC input as a threshold detector. The AD_EN pin will be used to enable or disable the blocking FET. The blocking FET must be chosen to handle the appropriate current level and the DC voltage level supplied from the input. In this example, the expectation is that the DC input will be 5 V with a maximum current of 1 A (same configuration as the wireless power supply). The CSD75207W15 is a good fit because it is a P-Channel, –20-V, 3.9-A FET pair in a 1.5-mm2 WCSP.

The following scope plots show behavior under different conditions.

Figure 9-7 shows the transition from wireless power to wired power when power is added to the AD pin. VRECT drops and there is a short time (IOUT drops to zero) when neither source is providing power. When Q1 is enabled (through AD_EN) the output current turns back on. Note the RECT voltage after about 500 ms. This is the TX sending a ping to check to see if power is required. RECT returns to low after the BQ51013C informs the TX it does not need power (without enabling the OUT pin). This timing is based on the TX (BQ500212A used here).

Figure 9-8 shows the transition to wireless power when the AD voltage is removed. Note that after wired power is removed, the next ping from the (BQ500212A) will energize the BQ51013C. Once the rectifier voltage is stable the output will turn on.

Figure 9-9 shows a system placed onto the transmitter with AD already powered. The TX sends a ping which the RX responds to and informs the TX that no power is needed. The ping will continue with the timing based on the TX used.

Figure 9-10 shows the AD added when the RX is not on a TX. This indicates normal start-up without requirement of the TX.