RobG wrote on Feb 9th, 2015, 4:09pm:#2 makes the most sense to me, but I've never had occasion to test it. In theory the fields should cancel at the centerline anyway.
Are they trying to kill the load from Miller effect between the two wires? Putting a middle wire just increases the coupling, unless the wire is infinitely thin. In that case it is just a tie.
Thanks Rob. The package designer wasn't advocating this. I have the room in my padring so I was trying to decide the best thing to do.
We had a phone call this morning and the package designer agrees with you. So #2 it is. Thanks for the help.
Interestingly, I extracted the pads, put in bondwire models, and so on and couldn't get a significant difference in the two approaches from a performance standpoint. My thinking is that it just doesn't matter that much, but avoiding having the parallel ground bondwire in the package cavity is probably the right thing.