Jetson Nano GPIO/I2C/UART 3V3 or 1V8 TTL, Need Possible Level Shifters?

Hello all!

I am designing a custom carrier board around the Jetson Nano Module. I am trying to figure out if the module has internal pull ups and/or level shifters for the 1V8 pins, or even if these are indeed 1V8 logic level pins? It seems there’s just some ambiguity from the datasheet which looks like these pins are 1V8 logic levels, but also that they have internal pull ups. Can someone help specify this?

To be more specific, I am trying to figure out if the UART/GPIO/I2C pins of the Nano are 1V8 and if they require external level shifters to read data from 3V3 or 5V signals?

Thank you!

Hi, can you list specific pins name? I2C pins have pull-up as they are OD type. UART lines pass thru 1.8V to 3.3V level shift, no pull-up in module. GPIO status can be changed by pinmux sheet setting.

Hello, thank you for the response. However, I don’t understand, can you be more clear?

Pin numbers are the following:
I2C: 185, 187, 189, 191, 232, 234
UART: 99, 101, 103, 105, 203, 205, 207, 209, 236, 238
GPIO: 118, 124, 126, 127, 206, 208, 216

Thank you

All I2C have pull-up in module.
No pu on UART.
These GPIOs are 1.8V level and no pu.

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Hi @Trumany

Thank you for the response. Ok so just to confirm, if I pass the following signal levels into those pins, it should be correct, see below please;

  1. I2C: 1.8V or 3V3 or 5V?
  2. UART: 1.8V
  3. GPIO: 1.8V

Thank you

Please find detail info of each pin in OEM DG and module datasheet in DLC.

Another question here, so for the I2C lines, you mentioned all I2C have pull ups in the Jetson Nano module, does this mean we do not need to add additional pull ups outside of the module?

Yes, it means no need to add external pull-ups for I2C.