Both supply VDDH and VDD in nRF52840

[Vikas Bhatt]

Below images detail given about VDD and VDDH in nRF52840_PS_v1.7 datasheet (5.3.1 Main supply). According to this we can not connect both supplies simultaneously right?, if yes then why are both supplies connected in the nRF52840 DK reference schematic(PCA10056_Schematic_And_PCB)?

Below image is of nRF52840 DK reference schematic (PCA10056_Schematic_And_PCB).

[ketiljo]

In this case, only VDDH is powered externally. VDD_nRF comes out from REG0 and needs to be connected to the other VDD pins to power the device.  

See https://infocenter.nordicsemi.com/topic/ps_nrf52840/power.html#unique_1591758884

[Vikas Bhatt]

Hello Ketiljo,

If we shorten VDDH to VDD_nRF then it will be in normal mode so it will work fine right? What are the advantages in the above image configuration?

[ketiljo]

Yes, normal voltage mode, max 3.6 V, is when VDDH is connected to VDD. High voltage mode is when VDDH is suppled with a higher voltage, max 5.5 V. For instance USB supply.