i.MX RT1170 LCD Backlight

[TM_MI]

Why the use of an external circuit to provide 40mA current to the LEDs? I thought the drive IC OTA5180A on the LCD board control the backlight current.

[kerryzhou]

Hi @TM_MI ,

    Which LCD board you are using now?

   If your LCD board already have the backlight driver circuit, you also can don't use the external driver, the RT1170-EVK design it, just for those LCD which don't have the backlight driver circuit.

   You also can see the RT1170-EVK board, BL-/BL+ R1823,R1824 related resistor is DNP, R1829 for the Backlight_CTL is also DNP.

So, for your own design, if LCD board contains the driver, your RT1170 board can don't add the related backlight control circuit.

Wish it helps you!

Best Regards,

Kerry

[TM_MI]

Hello @kerryzhou ,

I haven’t decided on a specific LCD, but I would prefer a built-in driver to save space on board and to have the option of changing the LCD, bigger screens require higher backlight current so different backlight control circuit.

Do you have any recommendation for LCD touch panels with built-in drivers?

Thank you for your reply.

Regards,

Tarek

[kerryzhou · Accepted solution]

Hi @TM_MI 

  If the RT1170 EVK don't want to add the backlight circuit, you can choose the EVK related LCD, as MIMXRT1170-EVK although provide the backlight circuit, but it is not used, as the LCD board already have the related driver.

Wish it helps you!

Best Regards,

Kerry