Regarding Open-Drain GPIOs

From AGX ORIN Pin Description file, for most of the Open-Drain GPIO pins, it is given as “Open-Drain, 1.8V (3.3V tolerant, back-drive capable to 1.8V)”.

From this, I understood that these pins do not require 1.8V Pull-up resistors externally. But they require pull-up resistor when 3.3V is used.

In short, 1.8V works like normal Push-Pull pins and when 3.3V is used it works like Open Drain.

Is my understanding correct?
Kindly Confirm.


Could you please reply on this?


Hi user127571,

I’m requesting the internal to review your queries.
Do you hit any issue with GPIO? Or just want to confirm your understanding?

Hi Kevin,
I’m designing a custom carrier board. Just need to confirm on these Open drain pin status.

No, pull-up is always necessary for OD pins.

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Hi Trumany,
From the TRM, it looks like only the 3.3V is Open Drain and 1.8V is Push Pull.

That is tolerance. For OD pin usage, pull-up is must.

OK, we will use pull-up for these 3.3V OD pins.
And when we use the other similar pins as 1.8V, no pull-up is required.

Am I right @Trumany ?

No. Are you using these pins for OD function or GPIO function? Pull-up is must only for OD usage. For those pins without pull-up on module, you can use it as GPIO or OD (adding external pull-up on carrier). Anyway, you should check the Orin pinmux sheet in DLC for usage of each pin.

We will be using these pins for GPIO function. We will not enable 3.3V tolerance and planning to use as only 1.8V Push-Pull.

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