SNVSCV5 October   2025 TPS923621

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 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
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Enable and Start-up
      2. 7.3.2 Under-Voltage Lockout (UVLO)
      3. 7.3.3 Shutdown
      4. 7.3.4 Boost Control Operation
      5. 7.3.5 Switching Peak Current Limit
      6. 7.3.6 Over-Voltage Protection
      7. 7.3.7 Output Current Setting
      8. 7.3.8 Output Current PWM Controlled Analog Dimming
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation Mode
      2. 7.4.2 Over-Voltage Protection Mode
      3. 7.4.3 Shutdown Mode
  9. 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 Inductor Selection
        2. 8.2.2.2 Schottky Diode Selection
        3. 8.2.2.3 Output Capacitor Selection
        4. 8.2.2.4 LED Current Set Resistor
        5. 8.2.2.5 Thermal Considerations
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

8.2.2.3 Output Capacitor Selection

The output capacitor is mainly selected to meet the requirement for the output ripple and loop stability. This ripple voltage is related to capacitance and capacitor equivalent series resistance (ESR). Assuming a capacitor with zero ESR, the minimum capacitance needed for a given ripple can be calculated with

Equation 7. C O U T = V O U T - V I N × I O U T V O U T × F S × V r i p p l e

where

  • Vripple = peak-to-peak output ripple

The additional part of the ripple caused by ESR is calculated using: Vripple_ESR = IOUT × RESR

Due to its low ESR, Vripple_ESR could be neglected for ceramic capacitors, a 1µF to 4.7µF capacitor is recommended for typical application.