Well heck, make that 500mA trace as large as possible, and decap it to the = gnd plane with a bulk (10uf) and several ceramic NPOs near the switcher, on= a plane to the pin and very nearby, with vias to gnd. ________________________________ From: piclist-bounces@mit.edu on behalf of Justin= Richards Sent: Wednesday, June 27, 2018 8:36 PM To: Microcontroller discussion list - Public. Subject: [EE]: 2 layer PCB layout. 12v and 5v tracks stacked. Good or bad Working on a 10cm x 10cm board. Vin is 12V, gets converted to 5v and 3.3v. Bottom plane is ground and top layer will be 3.3v flood. As always, space is constrained. I have routed the 12v (Vin) 2mm trace on the top layer around half of the perimeter. I want to route the regulated 5v 2mm trace directly underneath the 12v trace. Is this a bad idea. Should the 5v trace be routed such that it also runs on top of the ground plane. The 12v trace will be supplying an inductive load that gets switched on and off and draws about 500mA. Attached top half of the brd. Tried to make attachment as small as possible. Cheers justin --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .