Page 2 of 2

Posted: Sun Jan 08, 2017 4:56 pm
by frank
Please post the PCB, ground loops and broken return paths can cause lots of problems.

Posted: Sat Jan 14, 2017 9:12 am
by bxc1986
frank wrote:Please post the PCB, ground loops and broken return paths can cause lots of problems.
here are a few of the pcb, some before and after ratsnest so you can see the leads more clearly

https://goo.gl/photos/XdUBvHUhH4dDitTs6

https://goo.gl/photos/ULDywf7k4fAfP33S7

https://goo.gl/photos/FMhButGn7PhK4XZ96

https://goo.gl/photos/b5GaocTZigQnwLrQA

Posted: Sat Jan 14, 2017 3:17 pm
by frank
OK, I see a number of issues:

1. You are not really using a ground plane, all the ground connections should tie directly down to the ground plane. For example you have pin 4 tied to 25 and 24, they should not be tied like that they should all connect directly down to the plane

2. Lots of breaks in the pour, that will cause return loops which is bad.

3. You have the outputs tied together, do not do that as that can cause noise.

Posted: Fri Jan 20, 2017 6:17 am
by bxc1986
frank wrote:OK, I see a number of issues:

1. You are not really using a ground plane, all the ground connections should tie directly down to the ground plane. For example you have pin 4 tied to 25 and 24, they should not be tied like that they should all connect directly down to the plane

2. Lots of breaks in the pour, that will cause return loops which is bad.

3. You have the outputs tied together, do not do that as that can cause noise.
Thank you for your help! I'm going to address those issues, I'm still learning about PCB layout, I have some newer designs where I don't use a pour, i tie all the grounds together directly to ground, would that be better, or would a pour be better?

Posted: Fri Jan 20, 2017 9:44 pm
by frank
An unbroken pour is best.

Posted: Wed Jan 25, 2017 7:43 am
by bxc1986
frank wrote:An unbroken pour is best.
I've attached a picture where I have vias tying the ground pins from the FV-1 to the ground plane, would this be ok to do?

My hope is to run all the leads on the top layer so the bottom layer could be just the ground pour

https://goo.gl/photos/qgjPzXNSqn7rppY29