SLVSFC5 November   2020 TPS552882

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  VCC Power Supply
      2. 7.3.2  Operation Mode Setting
      3. 7.3.3  Input Undervoltage Lockout
      4. 7.3.4  Enable and Programmable UVLO
      5. 7.3.5  Soft Start
      6. 7.3.6  Shutdown
      7. 7.3.7  Switching Frequency
      8. 7.3.8  Switching Frequency Dithering
      9. 7.3.9  Inductor Current Limit
      10. 7.3.10 Internal Charge Path
      11. 7.3.11 Output Voltage Setting
      12. 7.3.12 Output Current Indication and Cable Voltage Drop Compensation
      13. 7.3.13 Integrated Gate Drivers
      14. 7.3.14 Output Current Limit
      15. 7.3.15 Overvoltage Protection
      16. 7.3.16 Output Short Circuit Protection
      17. 7.3.17 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 PWM Mode
      2. 7.4.2 Power Save Mode
  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 5V Power Supply Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Switching Frequency
        3. 8.2.2.3 Output Voltage Setting
        4. 8.2.2.4 Inductor Selection
        5. 8.2.2.5 Input Capacitor
        6. 8.2.2.6 Output Capacitor
        7. 8.2.2.7 Output Current Limit
        8. 8.2.2.8 Loop Stability
      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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
      2. 11.1.2 Development Support
        1. 11.1.2.1 Custom Design With WEBENCH® Tools
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Support Resources
    4. 11.4 Trademarks
    5. 11.5 Glossary
    6. 11.6 Electrostatic Discharge Caution

Package Options

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

8.2.2.5 Input Capacitor

In buck mode, the input capacitor supplies high ripple current. The RMS current in the input capacitors is given by Equation 14.

Equation 14. GUID-70189C42-99F5-4B0E-B557-44A2D74DBCBD-low.gif

where

  • ICIN(RMS) is the RMS current through the input capacitor
  • IOUT is the output current

The maximum RMS current occurs at the output voltage is half of the input voltage, which gives ICIN(RMS) = IOUT / 2. Ceramic capacitors are recommended for their low ESR and high ripple current capability. A total of 20-µF effective capacitance is a good starting point for this application.