NRF52480 DK external Supply

[ock]

When I just plug the USB cable on the board I get a GPIO high voltage of 3V. But when I also put +5V on the external supply pins, the GPIO high voltages are 4.5 V. Is this normal?

And if so, how can I change it to 3V?

I couldn't find something on this topic.

Best Regards

[MartinBL]

Hi,

What pins are you using when supplying the chip with +5V? You should only connect such a high voltage to the V_DDH pin. This voltage will then be regulated down to safe levels internally in the chip. Like this:

It sounds like you have connected 5V directly to the VDD pins. This is way above maximum operating voltage and will likely damage your chip. Please refer to the Power supply section in the Product Specification.

[ock]

I used the External Supply pins (P21). I could not find the V_DDH pin though.

edit: Okay so if I connect +5V to VDD nRF_HV it should work right?

[ock]

@Martin Børs-Lind or what about the VIN 3-5 V pin?

[MartinBL]

Sorry. I forgot that you were using a development kit and assumed you were working on a custom board. Please refer to this documentation to see how to connect 5V to the kit: infocenter.nordicsemi.com/.../hw_power_supply.html

[ock]

Thanks a lot!