External pull-up to 1.8V for USB-8452 I2C

Updated Apr 26, 2023

Reported In


  • USB-8452
  • USB-8452 OEM


  • NI-845x Driver Software 1.1
  • NI-845x Driver Software
  • NI-845x Driver Software 1.0
  • NI-845x Driver Software 2.0
  • NI-845x Driver Software 2.1

Issue Details

Is it possible to set externally pull-up voltage of 1.8V for I2C with USB-8452?
In some reason, I need to add pull-up resistors externally.


You can use USB-8452's onboard pull-up resistors to operate USB-8452 at a pull-up voltage of 1.8V. 
You can see this information in NI-845x Hardware and Software Manual as shown below.

Since an external pull-up to 1.8V is outside of USB-8452's specifications, NI can not guarantee it working properly at an external pull-up voltage of 1.8V. NI suggests to use internal pull-up resistors for 1.8V.   

Additional Information

You can activate onboard pull-up voltage through the NI-845x Device Property Node .