SLVSDR6C June   2017  – March 2018 TPS25740B

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  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  ENSRC
      2. 8.3.2  USB Type-C CC Logic (CC1, CC2)
      3. 8.3.3  USB PD BMC Transmission (CC1, CC2, VTX)
      4. 8.3.4  USB PD 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)
      7. 8.3.7  Configuring Power Capabilities (PSEL, PCTRL, HIPWR)
      8. 8.3.8  Gate Driver (GDNG, GDNS)
      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,CTL3)
      11. 8.3.11 Sink Attachment Indicator (DVDD)
      12. 8.3.12 Power Supplies (VAUX, VDD, VPWR, DVDD)
      13. 8.3.13 Grounds (AGND, GND)
      14. 8.3.14 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 Using ENSRC to Enable the Power Supply upon Sink Attachment
      3. 9.1.3 Use of GD Internal Clamp
      4. 9.1.4 Resistor Divider on GD for Programmable Start Up
      5. 9.1.5 Selection of the CTL1, CTL2, and CTL3 Resistors (R(FBL1), R(FBL2), and R(FBL3))
      6. 9.1.6 Voltage Transition Requirements
      7. 9.1.7 VBUS Slew Control using GDNG C(SLEW)
      8. 9.1.8 Tuning OCP using RF and CF
    2. 9.2 Typical Applications
      1. 9.2.1 Typical Application, A/C Power Source (Wall Adapter)
        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 Typical Application, 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 D/C Power Source (Power Hub)
      2. 9.3.2 A/C Power Source (Wall Adapter)
      3. 9.3.3 Dual-Port A/C Power Source (Wall Adaptor)
      4. 9.3.4 D/C Power Source (Power Hub with 3.3 V Rail)
  10. 10Power Supply Recommendations
    1. 10.1 VDD
    2. 10.2 VPWR
  11. 11Layout
    1. 11.1 Port Current Kelvin Sensing
    2. 11.2 Layout Guidelines
      1. 11.2.1 Power Pin Bypass Capacitors
      2. 11.2.2 Supporting Components
    3. 11.3 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation 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

9.1.7 VBUS Slew Control using GDNG C(SLEW)

Care should be taken to control the slew rate of Q1 using C(SLEW); particularly in applications where COUT>> C(SLEW). The slew rate observed on VBUS when charging a purely capacitive load is the same as the slew rate of V(GDNG) and is dominated by the ratio I(GDNON) / C(SLEW). R(SLEW) helps block C(SLEW) from the GDNG pin enabling a faster transient response to OCP.

TPS25740B Slew_Rate_Control_GDNG_slvsdr6.gifFigure 47. Slew-Rate control Using GDNG

There may be fault conditions where the voltage on VBUS triggers an OVP condition and then remains at a high voltage even after the TPS25740B configures the voltage source to output 5 V via the CTL pins. When this OVP occurs, the TPS25740B opens Q1 within tFOVP + tFOVPDG. The TPS25740B then issues a hard reset, discharge the power-path via the R(DSCG), and waits for 795 ms before enabling Q1 again. Due to the fault condition the voltage again triggers an OVP event when the voltage on VBUS exceeds V(FOVP). This retry process would continue as long as the fault condition persists, periodically pulsing up to V(FOVP) + VSrcSlewPos x (tFOVP + tFOVPDG) onto the VBUS of the Type-C receptacle. It is recommended to use a slew rate less than the maximum of VSrcSlewPos (30 mV / µs) allowed by USB (refer to Documentation Support), the slew rate should instead be set in order to meet the requirement to have the voltage reach the target voltage within tSrcSettle (275 ms). This also limits the out-rush current from the COUT capacitor into the C(PDIN) capacitor and help protect Q1 and RS.