In the MPM3820 datasheet it states that the NC pins must be left floating.
However in the EVM3820 board layout, the NC pins are shown connected to the SW pins (and also running through where the two inner NC pins are).
Can you say which one I should follow.
Wow they went to some trouble to connect those pins. Does the demo board work?
Page 17 of the datasheet they have a note specifically about pins 19 and 20 , so it seems not all NC are the same.
I actually don’t have the demo board, but I’d be surprised if it didn’t work.
The keep-out zone is probably observed as there is solder resist over the tracks that run through it.
I think you can generally follow the EVB datasheet since this is usually our recommended layout. However, the recommended layout from the datasheet of the MPM3820 shows that we should keep the NC pins floating:
My suggestion is to follow the recommended layout from the datasheet.
Field Applications Engineer
Monolithic Power Systems | MPS Now