Ixora Apalis iMX8 OTG port VDD issues

When using the OTG port with an Apalis iMX8QM module VDD supplied to the micro USB port while the module is in reset even when the ID pin left floating (the board should be a peripheral).

I’ve removed JP2 which mean that the ID pin on the OTG port should control if the module acts as a host or a peripheral. I haven’t actually tried getting OTG to work (we’ve only used it as peripheral so far), but I noticed that LED3 lights up when holding the module in reset. A peripheral is prohibited from injecting voltage on VDD, so this seams like an issue. Also, the i.MX6 modules doesn’t do this.

I’m guessing the i.MX8 module drives (or pulls up?) USBO1_EN when in reset without respecting USBO1_ID. I’m not sure if this is cased by the actual SoC or if it’s the SoM. But a quick fix would be to add some logic in the middle of the USBO1_EN line that ands the signal with USB01_ID inverted?

Hello SvenAlmgren,

we are looking into it. Which version of the IMX8QM you are using.

Best Regards,


Hi Matthias!

This happens on both Apalis iMX8QP 2GB WB V1.0B and Apalis iMX8QM 4GB WB V1.0B


Hello Sven,

Yes you are right! I talked to the hardware team. This is an issue that will be solved first the production version of the SOM as I heard. If you are designing you own carrier you can fix this with a pull down.

Best Regards,