SLVSDJ5D August   2016  – January 2018 TPS25741 , TPS25741A

UNLESS OTHERWISE NOTED, this document contains PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Implementations in DFP Host Ports
  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 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
      1. 8.1.1 VBUS Capacitance
      2. 8.1.2 USB Data Communications
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  USB Type-C CC Logic (CC1, CC2)
      2. 8.3.2  9.3.2 VCONN Supply (VCONN, CC1, CC2)
      3. 8.3.3  USB Power Delivery BMC Transmission (CC1, CC2, VTX)
      4. 8.3.4  USB Power Delivery BMC Reception (CC1, CC2)
      5. 8.3.5  Discharging (DSCG, VPWR)
        1. 8.3.5.1 Discharging after a Fault (VPWR)
      6. 8.3.6  Configuring Voltage Capabilities (HIPWR, EN9V, EN12V)
      7. 8.3.7  Configuring Power Capabilities (PSEL, PCTRL, HIPWR)
      8. 8.3.8  Gate Drivers
        1. 8.3.8.1 GDNG, GDNS
        2. 8.3.8.2 G5V
        3. 8.3.8.3 GDPG
      9. 8.3.9  Fault Monitoring and Protection
        1. 8.3.9.1 Over/Under Voltage (VBUS)
        2. 8.3.9.2 Over-Current Protection (ISNS, VBUS)
        3. 8.3.9.3 System Fault Input (GD, VPWR)
      10. 8.3.10 Voltage Control (CTL1, CTL2)
      11. 8.3.11 Sink Attachment Indicator (UFP, DVDD)
      12. 8.3.12 Accessory Attachment Indicator (AUDIO, DEBUG)
      13. 8.3.13 Plug Polarity Indication (POL)
      14. 8.3.14 Power Supplies (VAUX, VDD, VPWR, DVDD)
      15. 8.3.15 Grounds (AGND, GND)
      16. 8.3.16 Output Power Supply (DVDD)
    4. 8.4 Device Functional Modes
      1. 8.4.1 Sleep Mode
      2. 8.4.2 Checking VBUS at Start Up
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 System-Level ESD Protection
      2. 9.1.2 Use of GD Internal Clamp
      3. 9.1.3 Resistor Divider on GD for Programmable Start Up
      4. 9.1.4 Selection of the CTL1 and CTL2 Resistors (RFBL1 and RFBL2)
      5. 9.1.5 Voltage Transition Requirements
      6. 9.1.6 VBUS Slew Control using GDNG CSLEW
      7. 9.1.7 Tuning OCP Using RF and CF
    2. 9.2 Typical Applications
      1. 9.2.1 A/C Multiplexing Power Source
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1 Power Pin Bypass Capacitors
          2. 9.2.1.2.2 Non-Configurable Components
          3. 9.2.1.2.3 Configurable Components
        3. 9.2.1.3 Application Curves
      2. 9.2.2 D/C Power Source
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1 Power Pin Bypass Capacitors
          2. 9.2.2.2.2 Non-Configurable Components
          3. 9.2.2.2.3 Configurable Components
        3. 9.2.2.3 Application Curves
    3. 9.3 System Examples
      1. 9.3.1 A/C Power Source (Wall Adapter)
      2. 9.3.2 Dual-Port Power Managed A/C Power Source (Wall Adapter)
  10. 10Power Supply Recommendations
    1. 10.1 VDD
    2. 10.2 VCONN
    3. 10.3 VPWR
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Port Current Kelvin Sensing
      2. 11.1.2 Power Pin Bypass Capacitors
      3. 11.1.3 Supporting Components
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
    2. 12.2 Related Links
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.3 USB Power Delivery BMC Transmission (CC1, CC2, VTX)

An example of the BMC signal, specifically the end of the preamble and beginning of start-of-packet (SOP) is shown below. There is always an edge at the end of each bit or unit interval, and ones have an edge half way through the unit interval.

TPS25741 TPS25741A BMC_EEoP_beg_SOP_slvsdj5.gifFigure 25. BMC Encoded End of Preamble, Beginning of SOP

While engaging in USB Power Delivery communications, the TPS25741 or TPS25741A is applying IRP1.5 or IRP3.0, so the CC line has a DC voltage of 0.918 V or 1.68 V, respectively. When the BMC signal is transmitted on the CC line, the transmitter overrides this DC voltage as shown in Figure 26. The transmitter bias rail (VTX) is internally generated and may not be used for any other purpose in the system. The VTX pin is only high while the TPS25741 or TPS25741A is transmitting a USB Power Delivery message.

TPS25741 TPS25741A USB_PD_BMC.gifFigure 26. USB Power Delivery BMC Transmission on the CC Line

The device transmissions meet the eye diagram requirements from USB Power Delivery in Documentation Support. Figure 27 shows the transmitter schematic.

TPS25741 TPS25741A USB_PD_BMC_trans_slvsdj5.gifFigure 27. USB Power Delivery BMC Transmitter Schematic

The transmit eye diagram shown in Figure 29 was measured using the test load shown in Figure 28 with a CLOAD within the allowed range. The total capacitance CLOAD is computed as:

Equation 1. CLOAD = CRX + CCablePlug x 2 + Ca + CReceiver

Where:

  • 200 pF < CRX < 600 pF
  • CCablePlug < 25 pF
  • Ca < 625 pF
  • 200 pF < CReceiver < 600 pF

Therefore, 400 pF < CLOAD < 1850 pF.

TPS25741 TPS25741A Test_Load_BMC.gifFigure 28. Test Load for BMC Transmitter

Figure 29 shows the transmit eye diagram for the TPS25741 and TPS25741A.

TPS25741 TPS25741A transmit_eye_diagram_slbsdg8.pngFigure 29. Transmit Eye Diagram (BMC)

The transmitter bias rail (VTX) is internally generated and may not be used for any other purpose in the system. Connect a 0.1-µF capacitor to GND from this pin. The VTX pin is only high while the TPS25741/TPS25741A is transmitting a USB Power Delivery message.