Changing the default output of a GPIO in nRF5340 kit to be 3.3 v instead of 1.8 v.

RE: Changing the default output of a GPIO in nRF5340 kit to be 3.3 v instead of 1.8 v.

ARHasani — Thu, 03 Oct 2024 13:19:49 GMT

I tried the 2nd solution and worked for me. If 3.5V is also OK, you can simply use the VIN 3.5V pin of the board as the reference voltage, so you can connect it to the VIO REF.

RE: Changing the default output of a GPIO in nRF5340 kit to be 3.3 v instead of 1.8 v.

PaKa — Fri, 10 Nov 2023 15:43:45 GMT

Note: if you change the GPIO voltage to 3.0V, then PAN136 gets triggered. You will have to check the QSPI clock frequency used in this case.

infocenter.nordicsemi.com/.../anomaly_340_136.html

RE: Changing the default output of a GPIO in nRF5340 kit to be 3.3 v instead of 1.8 v.

Sigurd — Fri, 10 Nov 2023 13:04:44 GMT

Hi!

There are 2 alternatives on how this can be done.

1) If this should be permanent, it's possible to change the resistor values for the 1.8V regulator to make it generate 3.3V.It's not something we have intended for the customer to do. It's basically reading the datasheet of the regulator and change the resistor divider according to the formula. As these are 0201 components, you need steady hands and microscope to change it.
For 3.3V R60 =470k and R63 =150k.

2) If you have an external power supply (or voltage level), you can feed the VIO REF pin(with 3.3V), which will switch the power to the voltage follower circuit.