SLUSBX7C September 2014  – March 2017


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
  7. Specifications
    1. 7.1Absolute Maximum Ratings
    2. 7.2ESD Ratings
    3. 7.3Recommended Operating Conditions
    4. 7.4Thermal Information
    5. 7.5Electrical Characteristics
    6. 7.6Typical Characteristics
  8. Detailed Description
    1. 8.1Overview
    2. 8.2Functional Block Diagram
    3. 8.3Feature Description
      1. 8.3.1 Dynamic Rectifier Control
      2. 8.3.2 Dynamic Power Scaling
      3. 8.3.3 VO_REG Calculations
      4. 8.3.4 RILIM Calculations
      5. 8.3.5 Adapter Enable Functionality
      6. 8.3.6 Turning Off the Transmitter
        1. v1.2 EPT
      7. 8.3.7 Communication Current Limit
      8. 8.3.8  PD_DET and TMEM
      9. 8.3.9 TS/CTRL
      10. 8.3.10PMODE Pin
      11. 8.3.11I2C Communication
      12. 8.3.12Input Overvoltage
      13. 8.3.13Alignment Aid Using Frequency Information
    4. 8.4Device Functional Modes
    5. 8.5Register Maps
      1. 8.5.1 Wireless Power Supply Current Register 1
      2. 8.5.2 Wireless Power Supply Current Register 2
      3. 8.5.3 Wireless Power Supply Current Register 3
      4. 8.5.4 I2C Mailbox Register
      5. 8.5.5 I2C Mailbox Register 2
      6. 8.5.6 I2C Mailbox Register 3
      7. 8.5.7 Wireless Power Supply FOD RAM
      8. 8.5.8 Wireless Power User Header RAM
      9. 8.5.9 Wireless Power USER VRECT Status RAM
      10. 8.5.10Wireless Power VOUT Status RAM
      11. 8.5.11Wireless Power Proprietary Mode REC PWR MSByte Status RAM
      12. 8.5.12Wireless Power REC PWR LSByte Status RAM
      13. 8.5.13Wireless Power Prop Packet Payload RAM Byte 0
      14. 8.5.14Wireless Power Prop Packet Payload RAM Byte 1
      15. 8.5.15Wireless Power Prop Packet Payload RAM Byte 2
      16. 8.5.16Wireless Power Prop Packet Payload RAM Byte 3
  9. Application and Implementation
    1. 9.1Application Information
    2. 9.2Typical Applications
      1. 9.2.1WPC v1.2 Power Supply 7-V Output With 1.4-A Maximum Current With I2C
        1. Requirements
        2. Design Procedure
          1. Voltage Set Point
          2. and Rectifier Capacitors
          4. Output Current Set Point
          6. Current Limit
          7. Coil
          8. and Parallel Resonant Capacitors
          9., Boot, and Clamp Capacitors
        3. Curves
      2. 9.2.2Standalone 10-V WPC v1.2 Power Supply With 1-A Maximum Output Current in System Board
      3. 9.2.3Standalone 10-V Power Supply With 1-A Maximum Output Current for 2S Charging System
        1. Requirements
        2. Design Procedure
          1. Output Voltage Set Point
          2. Output and Rectifier Capacitors
          3. TMEM
          4. Maximum Output Current Set Point
          5. I2C
          6. Communication Current Limit
          7. Receiver Coil
          8. Series Resonant Capacitors
            1. Procedure
          9. Communication, Boot, and Clamp Capacitors
          10. Clamp
        3. Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1Layout Guidelines
    2. 11.2Layout Example
  12. 12Device and Documentation Support
    1. 12.1Receiving Notification of Documentation Updates
    2. 12.2Community Resources
    3. 12.3Trademarks
    4. 12.4Electrostatic Discharge Caution
    5. 12.5Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Orderable Information


  • Robust 10-W Receiver Solution Using Proprietary Protocol With TI's 10-W bq500215 Transmitter
    • Post-Regulation LDO to Protect External Charger Input from Rectifier Output Transients; Inductorless Solution for Lowest Height
    • Adjustable Output Voltage (4.5 to 10 V) for Coil and Thermal Optimization
    • Supports 2S Battery Configuration (Non-WPC compliant)
    • Fully Synchronous Rectifier With 96% Efficiency
    • 97% Efficient Post Regulator
    • 84% System Efficiency at 10 W
  • WPC v1.2 Compliant Communication and Control for Compatibility With Current TX Solutions
  • Patented Transmitter Pad Detect Function Improves User Experience
  • Power Signal Frequency Measurement Allows Host to Determine Optimal Placement on TX Surface
  • I2C Communication With Host


  • Smart Phones, Tablets, and Headsets
  • Point-of-Sale Devices
  • 2S Battery Applications
  • Power Banks
  • Other Portable Devices


The bq51025 device is a fully-contained wireless power receiver capable of operating in the Wireless Power Consortium (WPC) Qi protocol, which allows a wireless power system to deliver 5 W to the system with Qi inductive transmitters and up to 10 W when operating with the bq500215 primary-side controller. The bq51025 device provides a single device power conversion (rectification and regulation) as well as the digital control and communication as per WPC v1.2 specification. With market-leading 84% system efficiency and adjustable output voltage, the bq51025 device allows for unparalleled system optimization. With a maximum output voltage of 10 V, the bq51025 offers a flexible solution that offers a wireless power solution for 2S battery application and allows optimal thermal performance of the system. The I2C interface allows system designers to implement new features such as aligning a receiver on the transmitter surface or detecting foreign objects on the receiver. The bq51025 device complies with the WPC v1.2 communication protocol making it compatible with all WPC transmitter solutions. The receiver allows for synchronous rectification, regulation and control, and communication to all exist in a market-leading form factor, efficiency, and solution size.

Device Information(1)

bq51025DSBGA (42)3.60 mm × 2.89 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.


Simplified Schematic

bq51025 Simplified_schematic_slusbx7.gif

bq51025 System Efficiency With bq500215 TX Controller

bq51025 D001_SLUSBX7.gif