GPIO power of the nRF9160 with the LDO from the nRF52833


I'm working on a project involving both the nRF9160 and the nRF52833 on a single PCB. Since PCB space is at a premium for this project, I would like to know if it is possible to power the GPIO pins of the nRF9160 LTE-M modem with the internal LDO (REG0) of the nRF52833.

The Project will be powered by a regular USB wall power supply at 5 V.

This means that I will use the nRF52833 in high voltage mode.

My questions are:

- Can I use the internal LDO (REG0) of the nRF52833 to power the GPIO of the nRF9160?

- Should I implement some kind of load switch circuitry to comply with the nRF9160 Datasheet_v2.1 chapter 11.1 VDD_GPIO considerations?

The things that could happen with respect to power:

- The nRF9160 reset pin could be used while both VDD and VDD_GPIO are present.

- The nRF9160 enable pin could be pulled low while both VDD and VDD_GPIO are present.

- The GPIO pins of the nRF9160 could receive some voltage from the nRF52833 while the device is "reset" or "disabled".

--- Edit ---
Added schematic screenshot of power connections (without decoupling capacitors)

  • Hi,

    From the schematic you shared there seems to be missing some curtail components. Is this early in the prosess and you have not included the rest of the circuitry?(i see that you mention its without decupling caps)

    For the nrf9160 we do have guidelines that i recommend you look in to before finishing the design. 

    What do you plan on using nrf9160 GPIO's for?