SLVS850A June   2008  – September 2023 TPS2551-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Pin Configurations and Functions
  7. 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 Typical Characteristics
  8. 7 Parameter Measurement Information
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Overcurrent
      2. 8.3.2 Reverse-Voltage Protection
      3. 8.3.3 FAULT Response
      4. 8.3.4 Undervoltage Lockout (UVLO)
      5. 8.3.5 Enable (EN)
      6. 8.3.6 Thermal Sense
      7. 8.3.7 Device Functional Modes
    4. 8.4 Programming
      1. 8.4.1 Programming the Current-Limit Threshold
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Two-Level Current-Limit Circuit
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detail Design Procedure
        1. 9.2.3.1 Designing Above a Minimum Current Limit
        2. 9.2.3.2 Designing Below a Maximum Current Limit
        3. 9.2.3.3 Input and Output Capacitance
      4. 9.2.4 Auto-Retry Functionality
      5. 9.2.5 Latch-Off Functionality
      6. 9.2.6 Typical Application as USB Power Switch
        1. 9.2.6.1 Design Requirements
          1. 9.2.6.1.1 USB Power-Distribution Requirements
        2. 9.2.6.2 Detail Design Procedure
          1. 9.2.6.2.1 Universal Serial Bus (USB) Power-Distribution Requirements
    3. 9.3 Power Supply Recommendations
      1. 9.3.1 Self-Powered and Bus-Powered Hubs
      2. 9.3.2 Low-Power Bus-Powered and High-Power Bus-Powered Functions
      3. 9.3.3 Power Dissipation and Junction Temperature
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Receiving Notification of Documentation Updates
    2. 10.2 Support Resources
    3. 10.3 Trademarks
    4. 10.4 Electrostatic Discharge Caution
    5. 10.5 Glossary
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.4 Auto-Retry Functionality

Some applications require that an overcurrent condition disables the part momentarily during a fault condition and re-enables after a pre-set time. This auto-retry functionality can be implemented with an external resistor and capacitor. During a fault condition, FAULT pulls low disabling the part. The part is disabled when EN is pulled low, and FAULT goes high impedance allowing CRETRY to begin charging. The part re-enables when the voltage on EN reaches the turnon threshold, and the auto-retry time is determined by the resistor/capacitor time constant. The part continues to cycle in this manner until the fault condition is removed.

GUID-7494486D-992A-4FA2-BEA7-AA23383DD6EB-low.gifFigure 9-2 Auto-Retry Functionality

Some applications require auto-retry functionality and the ability to enable/disable with an external logic signal. The Figure 9-3 below shows how an external logic signal can drive EN through RFAULT and maintain auto-retry functionality. The resistor/capacitor time constant determines the auto-retry time-out period.

GUID-59C88E69-34A1-4F67-9F30-B9F11BCD56B9-low.gifFigure 9-3 Auto-Retry Functionality With External EN Signal