About VDD of nRF52840

[Youngjun]

Hi,

I'm implementing a circuit that uses both ble and usb communication using nRF52840.

I'm configuring power source and i'll configure schematic like reference circuit no.4.

I have some question about reference circuit.

1. Is the VDD_nRF not an external power source? 

  Are all the VDD_nRF lines in the circuit output from nRF52840?

2. I read that VDD level controlled by REGOUT0.

I'll use VDDH at 3.3V. 

Is it ok to set REGOUT0 to 3.3V?

Regards,

Youngjun

[Jared]

Hi,

1. Is the VDD_nRF not an external power source? 

  Are all the VDD_nRF lines in the circuit output from nRF52840?

In high voltage mode VDDH is the input for the supply while VDD is an output. VDD is the output of the REG0 regulator and produces VDD_nRF when the VDDH is supplied. All of the VDD nodes should be tied together externally so yes they are outputs. But note that there is a limit of maximum current draw from the VDD node.

2. I read that VDD level controlled by REGOUT0.

I'll use VDDH at 3.3V. 

Is it ok to set REGOUT0 to 3.3V?

Yes, that's ok.

regards

Jared