SLVSCL5A June   2014  – November 2020 TPS2559

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and 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 Timing Diagrams
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Thermal Sense
      2. 8.3.2 Overcurrent Protection
      3. 8.3.3 FAULT Response
    4. 8.4 Device Functional Modes
      1. 8.4.1 Operation with VIN Undervoltage Lockout (UVLO) Control
      2. 8.4.2 Operation with EN Control
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Step-by-Step Design Procedure
        2. 9.2.2.2 Input and Output Capacitance
        3. 9.2.2.3 Programming the Current-Limit Threshold
        4. 9.2.2.4 Design Above a Minimum Current Limit
        5. 9.2.2.5 Design Below a Maximum Current Limit
        6. 9.2.2.6 Accounting for Resistor Tolerance
        7. 9.2.2.7 Power Dissipation and Junction Temperature
        8. 9.2.2.8 Auto-Retry
        9. 9.2.2.9 Two-Level Current-Limit
      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 Receiving Notification of Documentation Updates
    2. 12.2 Support Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

9.2.2.3 Programming the Current-Limit Threshold

The overcurrent threshold is user programmable via an external resistor. The TPS2559 uses an internal regulation loop to provide a regulated voltage on the ILIM pin. The current-limit threshold is proportional to the current sourced out of ILIM. The recommended 1% resistor range for R(ILIM) is 24.9 kΩ ≤ R(ILIM) ≤ 100 kΩ to ensure stability of the internal regulation loop.

When ILIM pin short to GND (single point failure), maximum current limit is less than 8 A over temperature and process variation.

Many applications require that the minimum current limit is above a certain current level or that the maximum current limit is below a certain current level, so it is important to consider the tolerance of the overcurrent threshold when selecting a value for R(ILIM). The equations and the graph below can be used to estimate the minimum and maximum variation of the current-limit threshold for a predefined resistor value within R(ILIM) is 24.9 kΩ ≤ R(ILIM) ≤ 100 kΩ. This variation is an approximation only and does not take into account, for example, the resistor tolerance. For examples of more-precise variation of IOS refer to the current-limit section of the Section 7.5 table.

Equation 1. GUID-1539D6D4-6038-4179-B14D-633C3415255A-low.gif

24.9 kΩ ≤ R(ILIM) ≤ 100 kΩ

GUID-BFE9B600-E176-4B8B-8194-8D30F8A67BE6-low.pngFigure 9-2 Current-Limit vs R(ILIM)