Connections for nRF52 - SWD and VDD outputs

[RML]

I am designing a custom board with nRF52840, powered by USB, no battery, using its internal LDOs to supply other peripherals with 3.3V

I have two questions about pins/outputs:

1. Can I take the 3.3V from any of the VDD pins, or is one specifically the output (e.g. W1 in Circuit Configuration 1 in the data sheet)?

2. The GND, SWDIO and SWDCLK lines are obvious, but what do I connect the VDD line of the SWD programmer to? The USB power line (VUSB) or one of the VDD lines? Because VDDH and VBUS will be connected to VUSB, and the VDD lines will be separate.

[mweger]

While i do believe that you can supply 3.3v to any of the vdd pins you should probably have them all connected in a net. This prevents faults if there is a bad via etc. you connect the vdd to vdd of the programmer. If you're using the devboard as a programmer the devboard can supply power to the board without an external power supply. This is useful for debugging etc. You need to make sure that the correct voltage is on this line. USB is a 5v protocol.