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

8.1 Overview

The TPS2556-Q1 and TPS2557-Q1 are current-limited, power-distribution switches using N-channel MOSFETs for applications that might encounter short circuits or heavy capacitive loads . This device allows the user to program the current-limit threshold between 500 mA and 5 A (typical) via an external resistor. This device incorporates an internal charge pump and the gate-drive circuitry necessary to drive the N-channel MOSFET. The charge pump supplies power to the driver circuit and provides the necessary voltage to pull the gate of the MOSFET above the source. The charge pump operates from input voltages as low as 2.5 V and requires little supply current. The driver controls the gate voltage of the power switch. The driver incorporates circuitry that controls the rise and fall times of the output voltage to limit large current and voltage surges and provides built-in soft-start functionality. The TPS2556-Q1 and TPS2557-Q1 family limits the output current to the programmed current-limit threshold IOS during an overcurrent or short-circuit event by reducing the charge-pump voltage driving the N-channel MOSFET and operating it in the linear range of operation. The result of limiting the output current to IOS reduces the output voltage at OUT by no longer fully enhancing the N-channel MOSFET.