Iris board display backlight current

Hi there,

I have an iMX7 and Iris board. I have attached a display with a 40-pin connector, and have verified that this display works properly with a separate driver board.

  • Without the display, the Iris board starts up when powered.
  • With the display connected, the Iris LED flashes momentarily when powered up, and there’s a click, then the board is turned off.

I am suspecting maybe my display’s backlight is trying to draw too much current, given that it is a high brightness (800 Cd/m^2) display? But I cannot find specs on the Iris maximum current supply. Here are the specs for the display:

  • Forward voltage (V): min=17.8, typ=18.2, max=18.6
  • Forward current (mA): min=30, typ=40, max=50
  • Power consumption (W): typ=0.8

Is the problem possibly that the display draws too much current?

Ihab Awad

I looked more carefully and, though the pinouts on my display are similar, they are not identical (see clip from schematic attached). I am clearly going to have to come up with a way to remap the flex circuit pins from the Iris to those of the display.

I was hoping that I would avoid this tricky soldering job at this early stage of my project, but I guess this is inevitable. :slight_smile:

If you folks at Toradex have a recommendation for a 480x272 display that would fit exactly, I would appreciate it! I have been in contact with EDTC and this display of theirs seems perfect but it has an incompatible 44- or 45-pin connector. I will continue following up with my EDTC rep.


Ihab Awad
[1]: /community/storage/temp/394-pinout-lcd.png

Hi @ihab,
No, unfortunately we don’t have any 480x727 display which directly fits the FFC connector. I guess you are right and you have to go through building an adapter at that point.

Thank you so much for your help though! I’m looking forward to getting my prototype running! :slight_smile: