SLVAFI8 February   2023 TLC6C5748-Q1

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2Design Considerations for Low EMI
    1. 2.1 Design Considerations Overview
    2. 2.2 Considerations in Detail
      1. 2.2.1 Top-Level Architecture
      2. 2.2.2 High Frequency Signals
        1. 2.2.2.1  Original Setup
        2. 2.2.2.2  3.3 V I/O Voltage Instead of 5 V
        3. 2.2.2.3  Use Independent OSC for GSCLK With Spread Spectrum
        4. 2.2.2.4  Without Using Buffer on GSCLK
        5. 2.2.2.5  Using Snubber on GSCLK
        6. 2.2.2.6  Lower the Signal Frequency
        7. 2.2.2.7  Placement and PCB layout
        8. 2.2.2.8  ESD Enhancement
        9. 2.2.2.9  Demo and Test Results
        10. 2.2.2.10 Bench Test Results
  5. 3Summary
  6. 4References

3 Summary

This application note describes how to lower the EMI noise on local dimming LED driver circuit board. The process begins with the identification of the EMI noise source. By adding the snubber, external oscillator, and adjusting I/O voltage level can better the ECMI performance. Lastly, after doing all the countermeasures, please double check the signal waveform to meet the data sheet requirements.