HI,

What would be the best way to connect a back EMF diode to a PCB?

Would it be ok to connect it straight to the ground plane as in the first picture, or should I connect the 2 pins directly to each other and then connect to the ground plane with a 0ohm resistor (different net)?

Cheers,
Mike.

Ground Plane Connection


Connect to ground plane via 0ohm resistor

 

Idea #1 is cheap and cheerful.

Why add the extra part?

 

I do not see the advantage with using separate traces since the Back EMF milliamps is the same as the coil energized milliamps

Is BEMF actually causing an issue with your circuit?
What is the problem that you are trying to solve?
Or is this a solution, looking for problem?

If you really want to separate the Power Section, from the Logic Section,
then run separate Positive Bus and Negative Bus traces just for the Relay Coils.

 

A coil de-energizing diode should go ACROSS the coil, not to ground.

 

Thanks guys.

The first picture, direct to the ground plane is how I had it originally. I wasn't sure if it would work the same way like that or if it would cause problems with other components.

Cheers,
Mike.

 

A coil de-energizing diode should go ACROSS the coil, not to ground.

Pin 2 of the relay which is the coil goes straight to ground.