EMC software guidelines for TFT RBG LCD with iMXRT1064

[anujtanksali]

Hi,

During EMC tests the 7" TFT RGB LCD is becoming white. What can be done in pin configuration or software to pass the EMC test? We already have implemented Spread spectrum using ref AN12879

with spread range of 24MHz and other all tests are passing except the 7" TFT RGB LCD

Am using iMXRT1064 and MCUXpresso IDE.

Thanks

Anuj

[vicentegomez]

Normally when you have EMC problems it need to be solved by hardware modifications

Do you follow the recommendations on 

https://www.nxp.com/webapp/Download?colCode=MIMXRT105060HDUG

I hope this will help you

have a good day.

[anujtanksali]

Thanks for the reply
I understand the issues need to be resolved in hardware.
But are there any software guidelines to resolve the EMC issues?

I see some community posts mentioning to reduce the pin drive strength. Is this to be applied to all LCD, SDRAM or Backlight pins for only for clocks?

Thanks
Anuj

[vicentegomez]

Yes you can try that, also if this is possible you can test with different clock configurations, but maybe this is not a good option for your application

[anujtanksali]

Thanks for the reply.

As I see in MCUXpresso pin configuration the signal drive strength is represented in terms of R0/2, R0/4, R0/6 etc. Default setting is R0/6 

Can you please let me know the significance of this and It seems a lower setting should be set ie R0/4, R0/2, R0 to for reducing EMC issues?  Can you please confirm?

Thanks in advance

Anuj

[anujtanksali]

Hi,

Am Facing LCD ESD issues. The screen becomes white during ESD test when shocked with +-15kv. Can this be resolved in software using LCD Reset or by resetting some other LCD pins?.

If yes How do I reset the other LCD Pins as it seems the MCUXpresso does not allow to configure these pins except LCD DISP pin which is LCD reset.

Thanks

Anuj