Problem in copper area

Hi,

I have power supply followed by reverse protection diode and current sensor in my circuit.

I need to give all these components in single wide copper area.

The input is +24V which is given to the diode and diode output to current sensor.

So, can I give diode anode(input) and cathode(output) in single copper area(both are 24V)???

But as the anode and cathode are connecting(there is a problem of fusing away. Right???)

Can anyone suggest something about this??

I am attaching image with this message

Regards,
Vivek Alaparthi

What? You want to short your diode with copper? You have a diode with zero voltage drop "both are 24V"? I think you need to think about this a bit more. Do you REALLY want to short out a component with copper? And giving us a picture of an un-routed PCB doesn't tell us anything.

If you want copper for heat dissipation or noise reduction, then simply add a copper pour to your pcb. The software will take care of adding clearances so that you DON'T short out components. You probably want the copper tied to one (AND ONLY ONE) net.

barry said:

What? You want to short your diode with copper? You have a diode with zero voltage drop "both are 24V"? I think you need to think about this a bit more. Do you REALLY want to short out a component with copper? And giving us a picture of an un-routed PCB doesn't tell us anything.

If you want copper for heat dissipation or noise reduction, then simply add a copper pour to your pcb. The software will take care of adding clearances so that you DON'T short out components. You probably want the copper tied to one (AND ONLY ONE) net.

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Hi harry,

Thanks for your reply

Yes,I need to add copper to only one net.

I am attaching unrouted picture with this mail.

Can you please tell me that how can I do that???

As I said, you need to add a Copper Pour. Look at your help files. It's actually pretty easy.

barry said:

As I said, you need to add a Copper Pour. Look at your help files. It's actually pretty easy.

Click to expand...

Hi harry,

yes, its easy to add copper pour and I did it.

But why is copper pour used.

what is thermal dissipation and noise reduction??

In my case my professor suggested me to place input supply (and also high reverse current path devices) at the edge of the board

And use copper flooding in 3 layers (including top,power and bottom)???

For ground layer he suggested to give seperate GND to these components for good return current????

what does that mean and copper pour is good enough for this???

what is the idea behind using copper in 4 layers??

Regards,
Vivek Alaparthi

Copper is your friend, more is better (there are exceptions, but don't worry about that now). By using large areas of copper, you reduce the resistance for currents. Lower resistance means lower noise generated by transient currents, a big problem in switching power supplies, for example. Copper also will conduct heat away from components. The question of separate grounds is a big one, and you will find lots of debate on the merits of multiple grounds versus a single plane. In the past the philosophy was to have separate analog and digital grounds in a system, and tie them together at a single point. Now, it seems that a single ground plane is often used (I do) . Of course, you have to pay attention to where components are placed, etc.

3 layers, dont you have 4?
seperate grounds, like Barry said, can be prblematic, unless you realy know what you are doing, though making sure high current avoids low current is often a requirement, so creative seperation of the currents is advisable, but still only having one ground.

marce said:

3 layers, dont you have 4?
seperate grounds, like Barry said, can be prblematic, unless you realy know what you are doing, though making sure high current avoids low current is often a requirement, so creative seperation of the currents is advisable, but still only having one ground.

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Hi,

Thanks for your reply marsh,

You mean I should not use seperate grounds for the current path.

you mean the current path should be seperated but still having single ground????


Regards
Vivek

You can do things like have a channel cut in the plane which will restrict currents to one area of the plane.

barry said:

You can do things like have a channel cut in the plane which will restrict currents to one area of the plane.

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Hi barry,

Can I do it using plane area cut out in PADS

I'm not sure if that will work for copper pour, but you can draw any shape you want. You could also edit the pour shape, using the Split command, etc.