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

8.3.2 Overcurrent Protection

The TPS2559 responds to overcurrent conditions by limiting their output current to IOS. When an overload condition is present, the device maintains a constant output current, with the output voltage determined by (IOS × RLOAD). Two possible overload conditions can occur.

The first condition is when a short circuit or partial short circuit is present when the device is powered-up or enabled. The output voltage is held near zero potential with respect to ground and the TPS2559 ramps the output current to IOS. The TPS2559 limits the current to IOS until the overload condition is removed or the device begins to thermal cycle (see Figure 9-9).

The second condition is when a short circuit, partial short circuit, or transient overload occurs while the device is enabled and powered on. The device responds to the overcurrent condition within time tIOS (see Figure 7-4). The response speed and shape will vary with the overload level, input circuit, and rate of application. The current-limit response will vary between simply settling to IOS, or turnoff and controlled return to IOS. Similar to the previous case, the TPS2559 limits the current to IOS until the overload condition is removed or the device begins to thermal cycle.

The TPS2559 thermal cycles if an overload condition is present long enough to activate thermal limiting in any of the above cases. The device turns off when the junction temperature exceeds 135°C (min) while in current limit. The device remains off until the junction temperature cools 20°C (typ) and then restarts. The TPS2559 cycles on/off until the overload is removed (see Figure 9-10).