SLUSCE3C October   2015  – August 2020 TPS2549-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Parameter Measurement Information
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  FAULT Response
      2. 8.3.2  Cable Compensation
        1. 8.3.2.1 Design Procedure
      3. 8.3.3  D+ and D– Protection
      4. 8.3.4  Output and D+ or D– Discharge
      5. 8.3.5  Port Power Management (PPM)
        1. 8.3.5.1 Benefits of PPM
        2. 8.3.5.2 PPM Details
        3. 8.3.5.3 Implementing PPM in a System With Two Charging Ports (CDP and SDP1)
        4. 8.3.5.4 Implementing PPM in a System With Two Charging Ports (DCP and DCP1)
      6. 8.3.6  CDP and SDP Auto Switch
      7. 8.3.7  Overcurrent Protection
      8. 8.3.8  Undervoltage Lockout
      9. 8.3.9  Thermal Sensing
      10. 8.3.10 Current Limit Setting
    4. 8.4 Device Functional Modes
      1. 8.4.1 Device Truth Table (TT)
      2. 8.4.2 USB Specification Overview
      3. 8.4.3 Standard Downstream Port (SDP) Mode — USB 2.0 and USB 3.0
      4. 8.4.4 Charging Downstream Port (CDP) Mode
      5. 8.4.5 Dedicated Charging Port (DCP) Mode
        1. 8.4.5.1 DCP BC1.2 and YD/T 1591-2009
        2. 8.4.5.2 DCP Divider-Charging Scheme
        3. 8.4.5.3 DCP 1.2-V Charging Scheme
      6. 8.4.6 DCP Auto Mode
      7. 8.4.7 Client Mode
      8. 8.4.8 High-Bandwidth Data-Line Switches
  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 Input and Output Capacitance
        2. 9.2.2.2 Cable Compensation Calculation
        3. 9.2.2.3 Power Dissipation and Junction Temperature
    3. 9.3 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 Documentation Support
      1. 12.1.1 Related Documentation
    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
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

8.3.6 CDP and SDP Auto Switch

The TPS2549-Q1 device is equipped with a CDP and SDP auto-switch feature to support some popular phones in the market. These popular phones do not comply with the BC1.2 specification because they fail to establish a data connection in CDP mode. These phones use primary detection (used to distinguish between an SDP and different types of charging ports) to only identify ports as SDP (data, no charge) or DCP (no data, charge). These phones do not recognize CDP (data, charge) ports. When connected to a CDP port, these phones classify the port as a DCP and only charge the battery. Because the charging ports are configured as CDP, users do not receive the expected data connection.

GUID-1D2C2F9B-D00D-4396-97B6-F4CD5CA7B18F-low.gifFigure 8-5 CDP and SDP Auto-Switch

To remedy this problem, the TPS2549-Q1 device employs a CDP and SDP auto-switch scheme to ensure these BC1.2 noncompliant phones establish data connection using the following steps.

  1. The TPS2549-Q1 device determines when a noncompliant phone has wrongly classified a CDP port as a DCP port and has not made a data connection.
  2. The TPS2549-Q1 device automatically completes an OUT (VBUS) discharge and reconfigures the port as an SDP.
  3. When reconfigured as an SDP, the phone detects a connection to an SDP and establishes a data connection.
  4. The TPS2549-Q1 device then switches automatically back to a CDP without doing an OUT (VBUS) discharge.
  5. The phone continues to operate as if connected to an SDP because OUT (VBUS) was not interrupted. The port is now ready in CDP if a new device is attached.