SLVS736C February   2008  – October 2023 TPS2550 , TPS2551

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  6. 5 Device Comparison Table
  7. 6 Pin Configuration and Functions
  8. 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 Typical Characteristics
  9. 8 Parameter Measurement Information
  10. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Overcurrent
      2. 9.3.2 Reverse-Voltage Protection
      3. 9.3.3 FAULT Response
      4. 9.3.4 Undervoltage Lockout (UVLO)
      5. 9.3.5 ENABLE ( EN or EN)
      6. 9.3.6 Thermal Sense
      7. 9.3.7 Device Functional Modes
    4. 9.4 Programming
      1. 9.4.1 Programming the Current-Limit Threshold
  11. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Applications
      1. 10.2.1 Two-Level Current-Limit Circuit
      2. 10.2.2 Design Requirements
      3. 10.2.3 Detail Design Procedures
        1. 10.2.3.1 Designing Above a Minimum Current Limit
        2. 10.2.3.2 Designing Below a Maximum Current Limit
        3. 10.2.3.3 Input and Output Capacitance
      4. 10.2.4 Auto-Retry Functionality
      5. 10.2.5 Latch-Off Functionality
      6. 10.2.6 Typical Application as USB Power Switch
        1. 10.2.6.1 Design Requirements
          1. 10.2.6.1.1 USB Power-Distribution Requirements
        2. 10.2.6.2 Detail Design Procedures
          1. 10.2.6.2.1 Universal Serial Bus (USB) Power-Distribution Requirements
    3. 10.3 Power Supply Recommendations
      1. 10.3.1 Self-Powered and Bus-Powered Hubs
      2. 10.3.2 Low-Power Bus-Powered and High-Power Bus-Powered Functions
      3. 10.3.3 Power Dissipation and Junction Temperature
    4. 10.4 Layout
      1. 10.4.1 Layout Guidelines
      2. 10.4.2 Layout Example
  12. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.1 Overcurrent

The TPS2550/51 responds to an overcurrent condition by limiting its output current to the IOC and IOS levels shown in Figure 9-1. Three response profiles are possible depending on the loading conditions and are summarized in Figure 8-3.

One response profile occurs if the TPS2550/51 is enabled into a short-circuit. The output voltage is held near zero potential with respect to ground and the TPS2550/51 ramps the output current to IOS (see Figure 7-3).

A second response profile occurs if a short is applied to the output after the TPS2550/51 is enabled. The device responds to the overcurrent condition within time tIOS (see Figure 8-2). The current-sense amplifier is over-driven during this time and momentarily disables the internal current-limit MOSFET. The current-sense amplifier gradually recovers and limits the output current to IOS.

A third response profile occurs if the load current gradually increases. The device first limits the load current to IOC. If the load demands a current greater than IOC, the TPS2550/51 folds back the current to IOS and the output voltage decreases to IOS x RLOAD for a resistive load, which is shown in Figure 8-3.

The TPS2550/51 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 (typ). The device remains off until the junction temperature cools 15°C (typ) and then restarts. The TPS2550/51 cycles on/off until the overload is removed (see Figure 7-5 and Figure 7-7) .