Can i interface 5V sesnors with nrf52840?

[arshdeep]

Hello Nordic Team,

I have few analog sensors that operate at 5V DC and outputs voltage signal within 0.5V - 4.5V range. I know i cannot interface these sensors with nrf52832 but can i use them with nrf52840? If yes, then do i have to use any level- shifter or i can interface directly? 

Thanks,

[Håkon Alseth]

Hi,

 

Is this an input only, or is this a bi-directional signal? I am guessing only input, since you mention analog sensors.

If it is only a input signal to the nRF, you could use a voltage divider. If it is a bi-directional signal, then you might need a level shifter.

 

Cheers,

Håkon

[arshdeep]

Hello Alseth,

Thanks for your response. Yes, it is only input. As you said I can use the voltage divider to drop down the sensing voltage but is it safe and possible to provide 5V power to sensor using the nrF?

Thanks,

[Håkon Alseth]

You should design the voltage divider in such a way that the voltage seen by the nRF GPIO is <= VDD_NRF + 0.3V, to ensure that you are within the specifications. The nRF52840 has an option to use REGOUT0, but this is up to 3.3V (and has two current erratas that currently limits its use-case: DCDC of REG0 not functional & Device does not start up in high voltage mode)

If you need more than 3.3V for your sensor, you should source it from the main battery/power source.