SNVSCQ2A March   2025  – August 2025 LP5817

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 Timing Diagrams
    8. 6.8 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 Analog Dimming
      2. 7.3.2 PWM Dimming
      3. 7.3.3 Sloper
      4. 7.3.4 Protections
        1. 7.3.4.1 UVLO
        2. 7.3.4.2 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Initialization Mode
      2. 7.4.2 Standby and Normal Mode
      3. 7.4.3 Shutdown Mode
      4. 7.4.4 Thermal Shutdown Mode
    5. 7.5 Programming
      1. 7.5.1 I2C Data Tansactions
      2. 7.5.2 I2C Data Format
      3. 7.5.3 Command Description
    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 Program Procedure
        2. 8.2.3.2 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

7.3.2 PWM Dimming

The LP5817 supports 8-bit PWM dimming with 23kHz frequency. The device integrates an internal 6MHz oscillator to generate the PWM clock.

The PWM output value of each channel is controlled by the OUT0_MANUAL_PWM, OUT1_MANUAL_PWM, OUT2_MANUAL_PWM separately.

If OUT0_FADE_EN, OUT1_FADE_EN, OUT2_FADE_EN bit in DEV_CONFIG2 register is set as 0, the output PWM value updates immeditaly to the latest received PWM set value.

If OUT0_FADE_EN, OUT1_FADE_EN, OUT2_FADE_EN bit in DEV_CONFIG2 register is set as 1, the fade in or out function is enabled, the output PWM ramps up or down smoothly to the latest received PWM value within the time period defined by OUT_FADE_TIME automatically.

The LP5817 allows users to configure the dimming scale as exponential curve or linear curve for each channel separately through the OUT0_EXP_EN, OUT1_EXP_EN, OUT2_EXP_EN in DEV_CONFIG3 register. A human-eye-friendly visual performance can be achieved by using the internal exponential scale. The linear scale has great linearity between PWM duty cycle and PWM setting value, which provides flexible approach for external controlled gamma correction algorithm. The 8-bit linear and exponential curves are shown as Figure 7-2.

LP5817 Linear and Exponential PWM Dimming Curves Figure 7-2 Linear and Exponential PWM Dimming Curves