SLVSC97B March   2014  – September 2020 TPS2556-Q1 , TPS2557-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Application
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Terminal Configuration and Functions
    1.     Terminal Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 Handling Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Switching Characteristics
    7. 7.7 Typical Characteristics
      1.      16
        1.       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 Overcurrent Conditions
      2. 8.3.2 FAULT Response
      3. 8.3.3 Thermal Sense
    4. 8.4 Device Functional Modes
      1. 8.4.1 Undervoltage Lockout (UVLO)
      2. 8.4.2 Enable ( EN OR EN)
      3. 8.4.3 Auto-Retry Functionality
      4. 8.4.4 Two-Level Current-Limit Circuit
  9. 9 Applications and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application, Design for Current Limit
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Determine Design Parameters
        2. 9.2.2.2 Programming the Current-Limit Threshold
        3. 9.2.2.3 Selecting Current-Limit Resistor 1
        4. 9.2.2.4 Selecting Current-Limit Resistor 2
        5. 9.2.2.5 Accounting for Resistor Tolerance
        6. 9.2.2.6 Power Dissipation and Junction Temperature
      3. 9.2.3 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 Related Links
    2. 12.2 Trademarks
    3. 12.3 Electrostatic Discharge Caution
    4. 12.4 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.4.3 Auto-Retry Functionality

Some applications require that an overcurrent condition disable the device momentarily during a fault condition and re-enables it after a preset time. This auto-retry functionality can be implemented with an external resistor and capacitor. During a fault condition, FAULT pulls EN low. Pulling EN below the turnoff threshold disables the part is disabled, and FAULT goes into the high-impedance state, allowing CRETRY to begin charging. The device re-enables when the voltage on EN reaches the turnon threshold. The resistor-capacitor time constant determines the auto-retry time. The device continues to cycle in this manner until removal of the fault condition.

GUID-1BE09249-CA4C-47B7-8B68-89666A54B68E-low.gifFigure 8-1 Auto-Retry Functionality

Some applications require auto-retry functionality and the ability to enable and disable with an external logic signal. Figure 8-2 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-2F9C1725-657C-4E1D-AA68-054843497DBC-low.gifFigure 8-2 Auto-Retry Functionality With External EN Signal