SNVSCC4C October   2023  – February 2025 LP5811

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  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 Timing Requirements
    7. 6.7 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 Synchronous Boost Converter
        1. 7.3.1.1 Undervoltage Lockout
        2. 7.3.1.2 Enable and Soft Start
        3. 7.3.1.3 Switching Frequency
        4. 7.3.1.4 Current Limit Operation
        5. 7.3.1.5 Boost PWM Mode
        6. 7.3.1.6 Boost PFM Mode
      2. 7.3.2 Analog Dimming
      3. 7.3.3 PWM Dimming
      4. 7.3.4 Autonomous Animation Engine Control
        1. 7.3.4.1 Animation Engine Pattern
        2. 7.3.4.2 Sloper
        3. 7.3.4.3 Animation Engine Unit (AEU)
        4. 7.3.4.4 Animation Pause Unit (APU)
      5. 7.3.5 Protections and Diagnostics
        1. 7.3.5.1 Overvoltage Protection
        2. 7.3.5.2 Output Short-to-Ground Protection
        3. 7.3.5.3 LED Open Detections
        4. 7.3.5.4 LED Short Detections
        5. 7.3.5.5 Thermal Shutdown
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
    6. 7.6 Register Maps
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Application
      2. 8.2.2 Design Parameters
      3. 8.2.3 Detailed Design Procedure
        1. 8.2.3.1 Inductor Selection
        2. 8.2.3.2 Output Capacitor Selection
        3. 8.2.3.3 Input Capacitor Selection
        4. 8.2.3.4 Program Procedure
        5. 8.2.3.5 Programming Example
      4. 8.2.4 Application Performance Plots
    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 Documentation 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

Package Options

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

7.3.1.3 Switching Frequency

The LP5811 switches at quasi-constant 1MHz frequency when the input voltage is above 1.5V. When the input voltage is lower than 1.5V, the switching frequency is reduced gradually to 0.5MHz, which improves the boost efficiency and gets higher boost ratio. When the input voltage is below 1V, the switching frequency is fixed at quasi-constant 0.5MHz.