SLVSDT3D January   2018  – December 2019 TPS25221

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin 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 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Over-current Conditions
      2. 9.3.2 Fault Response
      3. 9.3.3 Undervoltage Lockout (UVLO)
      4. 9.3.4 Enable, (EN)
      5. 9.3.5 Thermal Sense
    4. 9.4 Device Functional Modes
    5. 9.5 Programming
      1. 9.5.1 Programming the Current-Limit Threshold
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Constant-Current
    2. 10.2 Typical Applications
      1. 10.2.1 Two-Level Current-Limit Circuit
        1. 10.2.1.1 Design Requirements
        2. 10.2.1.2 Detailed Design Procedures
          1. 10.2.1.2.1 Designing Above a Minimum Current Limit
          2. 10.2.1.2.2 Designing Below a Maximum Current Limit
          3. 10.2.1.2.3 Accounting for Resistor Tolerance
          4. 10.2.1.2.4 Input and Output Capacitance
        3. 10.2.1.3 Application Curve
      2. 10.2.2 Auto-Retry Functionality
        1. 10.2.2.1 Design Requirements (added)
        2. 10.2.2.2 Detailed Design Procedure
      3. 10.2.3 Typical Application as USB Power Switch
        1. 10.2.3.1 Design Requirements
          1. 10.2.3.1.1 USB Power-Distribution Requirements
        2. 10.2.3.2 Detailed Design Procedure
          1. 10.2.3.2.1 Universal Serial Bus (USB) Power-Distribution Requirements
  11. 11Power Supply Recommendations
    1. 11.1 Self-Powered and Bus-Powered Hubs
    2. 11.2 Low-Power Bus-Powered and High-Power Bus-Powered Functions
    3. 11.3 Power Dissipation and Junction Temperature
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
    2. 13.2 Documentation Support
      1. 13.2.1 Related Documentation
    3. 13.3 Receiving Notification of Documentation Updates
    4. 13.4 Community Resources
    5. 13.5 Trademarks
    6. 13.6 Electrostatic Discharge Caution
    7. 13.7 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

10.2.1 Two-Level Current-Limit Circuit

Some applications require different current-limit thresholds depending on external system conditions. Figure 25 shows an implementation for an externally controlled, two-level current-limit circuit. The current-limit threshold is set by the total resistance from ILIM to GND (see the Programming the Current-Limit Threshold section). A logic-level input enables or disables MOSFET Q1 and changes the current-limit threshold by modifying the total resistance from ILIM to GND. Additional MOSFET and resistor combinations can be used in parallel to Q1/R2 to increase the number of additional current-limit levels.

NOTE

ILIM must never be driven directly with an external signal.
TPS25221 two_cur_limt_slvsdt3.gifFigure 25. Two-Level Current-Limit Circuit