SLVSES4C September   2019  – June 2021 TPS54J060

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Enable and Internal LDO
      2. 7.3.2  Split Rail and External LDO
      3. 7.3.3  Output Voltage Setting
      4. 7.3.4  Soft Start and Output-Voltage Tracking
      5. 7.3.5  Frequency and Operation Mode Selection
      6. 7.3.6  D-CAP3 Control
      7. 7.3.7  Current Sense and Positive Overcurrent Protection
      8. 7.3.8  Low-side FET Negative Current Limit
      9. 7.3.9  Power Good
      10. 7.3.10 Overvoltage and Undervoltage Protection
      11. 7.3.11 Out-Of-Bounds Operation (OOB)
      12. 7.3.12 Output Voltage Discharge
      13. 7.3.13 UVLO Protection
      14. 7.3.14 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Auto-Skip Eco-Mode Light Load Operation
      2. 7.4.2 Forced Continuous-Conduction Mode
      3. 7.4.3 Pre-Bias Start-up
  8. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1  Choose the Switching Frequency and Operation Mode (MODE Pin)
        2. 8.2.2.2  Choose the Output Inductor (L)
        3. 8.2.2.3  Set the Current Limit (TRIP)
        4. 8.2.2.4  Choose the Output Capacitors (COUT)
        5. 8.2.2.5  Choose the Input Capacitors (CIN)
        6. 8.2.2.6  Feedback Network (FB Pin)
        7. 8.2.2.7  Soft Start Capacitor (SS/REFIN Pin)
        8. 8.2.2.8  EN Pin Resistor Divider
        9. 8.2.2.9  VCC Bypass Capacitor
        10. 8.2.2.10 BOOT Capacitor
        11. 8.2.2.11 Series BOOT Resistor and RC Snubber
        12. 8.2.2.12 PGOOD Pullup Resistor
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Support Resources
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Trademarks
    5. 11.5 Glossary
    6. 11.6 Electrostatic Discharge Caution
  12. 12Mechanical, Packaging, and Ordering Information

Package Options

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

8.2.2.7 Soft Start Capacitor (SS/REFIN Pin)

The capacitor placed on the SS/REFIN pin can be used to extend the soft-start time past the internal 1.5-ms soft start. This example uses a 2-ms soft start time and the required external capacitance can be calculated with Equation 28. In this example, a 22-nF capacitor is used.

Equation 28. GUID-97C585A2-0B46-4100-A828-F82C8B7A86CB-low.gif
Note: A minimum capacitor value of 1 nF is required at the SS/REFIN pin to help bypass noise. Also, the SS/REFIN capacitor must use the AGND pin for its ground. Note, any CSS calculation that uses a soft-start time of less than 1.5 ms will be ignored by the internal soft-start time circuit. Therefore, selecting a capacitor less than or equal to 15 nF will result in the internal default 1.5 ms soft-start time.