Hello,
I'm starting to build/develop a project around the ISP2053 (nRF5340 module) and I'm a bit confused with the schematics. In some of the schematics, there is a "VDD_nRF" referenced (see example below). It often appears connected to the VDD pin but seems to be a separate voltage source to VDD. What really throws me off is that the chip doesnt have any pin named VDD_nRF. Can anyone explain the difference between the two?
Thanks in advance.
VDD_nRF is the net labeled used for the voltage on the nRF5340 that supplies the VDD net. As you can see there is also a VDD_HV net label for the High voltage net. 
On most of the nRF chips there are 2 supply options, you can often use normal voltage mode or high voltage mode, the name does vary a bit from product to product, but the main idea here is that there are two options to supply the device. The pins them self are named VDD or VDDH in most cases, but there are other labels for GPIO supply on the 91 series.
Regards,
Jonathan
