SLVSBD0B November   2012  – June 2020

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Typical Application as USB Power Switch
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  6. Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  7. Parameter Measurement Information
  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 Reverse-Voltage Protection
      3. 8.3.3 FAULT Response
      4. 8.3.4 Undervoltage Lockout (UVLO)
      5. 8.3.5 Enable (EN)
      6. 8.3.6 Thermal Sense
    4. 8.4 Device Functional Modes
    5. 8.5 Programming
      1. 8.5.1 Programming the Current-Limit Threshold
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Constant-Current and Impact on Output Voltage
      2. 9.1.2 Accounting for Resistor Tolerance
      3. 9.1.3 Input and Output Capacitance
    2. 9.2 Typical Applications
      1. 9.2.1 Application 1: Designing Above a Minimum Current-Limit
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2 Application 2: Designing Below a Maximum Current-Limit
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
      3. 9.2.3 Application 3: Auto-Retry Functionality
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
      4. 9.2.4 Application 4: Two-Level Current-Limit Circuit
        1. 9.2.4.1 Design Requirements
        2. 9.2.4.2 Detailed Design Procedure
      5. 9.2.5 Application 5: Typical Application as USB Power Switch
        1. 9.2.5.1 Design Requirements
        2. 9.2.5.2 Detailed Design Procedure
          1. 9.2.5.2.1 Universal Serial Bus (USB) Power-Distribution Requirements
  10. 10Power Supply Recommendations
    1. 10.1 USB Self-Powered (SPH) and Bus-Powered (BPH) Hubs
    2. 10.2 USB Low-Power Bus-Powered and High-Power Bus-Powered Functions
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
    3. 11.3 Power Dissipation and Junction Temperature
  12. 12Device and Documentation Support
    1. 12.1 Device Support
    2. 12.2 Support Resource
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Detailed Design Procedure

For this example, assume that 1 A must be delivered to the load so that the minimum desired current-limit threshold is 1000 mA. Use the IOS equations and Figure 22 to select RILIM.

Equation 2. TPS2553-Q1 eq_app1_1st_lvs841.gif

Select the closest 1% resistor less than the calculated value: RILIM = 23.7 kΩ. This sets the minimum current-limit threshold at 1 A . Use the IOS equations, Figure 22, and the previously calculated value for RILIM to calculate the maximum resulting current-limit threshold.

Equation 3. TPS2553-Q1 eq_app1_2nd_lvs841.gif

The resulting maximum current-limit threshold is 1172.4 mA with a 23.7 kΩ resistor.