SLVSFJ9 September   2021 TPS25854-Q1 , TPS25855-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (Continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Timing Requirements
    7. 8.7 Switching Characteristics
    8. 8.8 Typical Characteristics
  9. 9 Parameter Measurement Information
  10. 10Detailed Description
    1. 10.1 Overview
    2. 10.2 Functional Block Diagram
    3. 10.3 Feature Description
      1. 10.3.1  Power Down or Undervoltage Lockout
      2. 10.3.2  Input Overvoltage Protection (OVP) - Continuously Monitored
      3. 10.3.3  Buck Converter
      4. 10.3.4  FREQ/SYNC
      5. 10.3.5  Bootstrap Voltage (BOOT)
      6. 10.3.6  Minimum ON-time, Minimum OFF-time
      7. 10.3.7  Internal Compensation
      8. 10.3.8  Current Limit and Short Circuit Protection
        1. 10.3.8.1 USB Switch Programmable Current Limit (ILIM)
        2. 10.3.8.2 Cycle-by-Cycle Buck Current Limit
        3. 10.3.8.3 OUT Current Limit
      9. 10.3.9  Cable Compensation
      10. 10.3.10 Thermal Management With Temperature Sensing (TS) and OTSD
      11. 10.3.11 Thermal Shutdown
      12. 10.3.12 FAULT Indication
      13. 10.3.13 USB Specification Overview
      14. 10.3.14 USB Type-C® Basics
        1. 10.3.14.1 Configuration Channel
        2. 10.3.14.2 Detecting a Connection
        3. 10.3.14.3 Plug Polarity Detection
      15. 10.3.15 USB Port Operating Modes
        1. 10.3.15.1 USB Type-C® Mode
        2. 10.3.15.2 Dedicated Charging Port (DCP) Mode
          1. 10.3.15.2.1 DCP BC1.2 and YD/T 1591-2009
          2. 10.3.15.2.2 DCP Divider-Charging Scheme
          3. 10.3.15.2.3 DCP 1.2-V Charging Scheme
        3. 10.3.15.3 DCP Auto Mode
    4. 10.4 Device Functional Modes
      1. 10.4.1 Shutdown Mode
      2. 10.4.2 Active Mode
  11. 11Application and Implementation
    1. 11.1 Application Information
    2. 11.2 Typical Applications
      1. 11.2.1 Design Requirements
      2. 11.2.2 Detailed Design Procedure
        1. 11.2.2.1 Output Voltage Setting
        2. 11.2.2.2 Switching Frequency
        3. 11.2.2.3 Inductor Selection
        4. 11.2.2.4 Output Capacitor Selection
        5. 11.2.2.5 Input Capacitor Selection
        6. 11.2.2.6 Bootstrap Capacitor Selection
        7. 11.2.2.7 Undervoltage Lockout Set-Point
        8. 11.2.2.8 Cable Compensation Set-Point
        9. 11.2.2.9 FAULT, POL, and THERM_WARN Resistor Selection
      3. 11.2.3 Application Curves
  12. 12Power Supply Recommendations
  13. 13Layout
    1. 13.1 Layout Guidelines
    2. 13.2 Layout Example
    3. 13.3 Ground Plane and Thermal Considerations
  14. 14Device and Documentation Support
    1. 14.1 Receiving Notification of Documentation Updates
    2. 14.2 Support Resources
    3. 14.3 Trademarks
    4. 14.4 Electrostatic Discharge Caution
    5. 14.5 Glossary
  15. 15Mechanical, Packaging, and Orderable Information

Package Options

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

10.4.2 Active Mode

The TPS2585x-Q1 is in active mode when VEN is above the precision enable threshold, VSENSE is above its respective UVLO levels and a valid detection has been made on the CC lines. The simplest way to enable the TPS2585x-Q1 is to connect the EN pin to SENSE pin. This connection allows self startup when the input voltage is in the operating range (5.5 V to 26 V) and a UFP detection is made.

In active mode, the TPS2585x-Q1 buck regulator operates even though Rd is not inserted. Then the buck regulator operates with Forced Pulse Width Modulation (FPWM), also referred to as Forced Continuous Conduction Mode (FCCM). This action ensures the buck regulator switching frequency remains constant under all load conditions. FPWM operation provides low output voltage ripple, tight output voltage regulation, and constant switching frequency. Built-in spread-spectrum modulation aids in distributing spectral energy across a narrow band around the switching frequency programmed by the FREQ/SYNC pin. Under light load conditions the inductor current is allowed to go negative. A negative current limit of IL-NEG-LS is imposed to prevent damage to the regulator's low side FET. During operation, the TPS2585x-Q1 synchronizes to any valid clock signal on the FREQ/SYNC input.