SNVSB77B December   2019  – September 2021 TPSM53603

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 (VIN = 5 V)
    7. 6.7 Typical Characteristics (VIN = 12 V)
    8. 6.8 Typical Characteristics (VIN = 24 V)
    9. 6.9 Typical Characteristics (VIN = 36 V)
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Switching Frequency
      3. 7.3.3  Input Capacitors
      4. 7.3.4  Output Capacitors
      5. 7.3.5  Output On/Off Enable (EN)
      6. 7.3.6  Programmable Undervoltage Lockout (UVLO)
      7. 7.3.7  Power Good (PGOOD)
      8. 7.3.8  Light Load Operation
      9. 7.3.9  Voltage Dropout
      10. 7.3.10 Overcurrent Protection (OCP)
      11. 7.3.11 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Active Mode
      2. 7.4.2 Auto Mode
      3. 7.4.3 Shutdown 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 Detailed Design Procedure
        1. 8.2.2.1 Custom Design With WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Setpoint
        3. 8.2.2.3 Input Capacitors
        4. 8.2.2.4 Output Capacitor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Examples
    3. 10.3 Theta JA versus PCB Area
    4. 10.4 Package Specifications
    5. 10.5 EMI
  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 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Receiving Notification of Documentation Updates
    4. 11.4 Support Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.8 Light Load Operation

In light load conditions, the device turns on the high-side MOSFET until the inductor current reaches a controlled minimum value of approximately 1 A. As the input voltage decreases, reducing the voltage headroom between VIN and VOUT, the amount of time required to reach this minimum current increases. During this time, additional energy flows from VIN to VOUT, resulting in increased output voltage ripple. To eliminate this behavior, the EN UVLO function must be used to maintain at least 1 V of headroom above VOUT. Alternatively, additional output capacitance can be added to reduce the output voltage ripple in applications that operate at light loads with very low VIN to VOUT headroom.