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Help with KiCAD Footprint for Power SOIC-8

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LoveLaika:
I'm using the LM7372 dual op-amp IC as part of my circuit. It comes in a Power-SOIC-8 package with an exposed pad, and I need some help implementing it in KiCAD.

To start off, I uploaded Digikey's library of KiCAD footprints to use as a reference and modified it a bit to match the LM7372 datasheet (shown in image below). I have two questions.

1. The exposed center pad has to be left electrically floating. Since it has vias, I want to add a small copper pour section to form an isolated copper island within my ground plane that is connected to the exposed pad. How do I do that?

2. The original footprint had two square rectangle pads for the exposed pad, with one pad being longer than the other. I deleted the long one as shown in the picture, and I adjusted the center pad so it is the size of what is recommended in the datasheet. For those who have used this type of component before, should I make the exposed pad longer than normal, or should I just keep it the fixed size?


https://www.ti.com/lit/ds/symlink/lm7372.pdf

phil from seattle:
The datasheet shows a different footprint than you describe.  I think I'd follow the datasheet.

There is probably a better way but I would add a pad to the footprint for the exposed pad, add a pin for it in the symbol. In the schematic, connect it to something (so you get a net, maybe create a symbol for that), in the PCB create a filled zone (or zones) for that net and draw it however you like.  Turn off thermal relief for the pad. 

LoveLaika:
Thanks for replying. If I may, whats different about the footprint? Its mildly different with more via holes and the pads a bit longer, but otherwise, the dimensions are right, and TI's 3D model fits it.

I tried adding a copper pour tied to the exposed pad net on my ground pour,but it didnt isolate from the ground plane.

phil from seattle:
You described multiple pads.

You need to set the net of the Copper Zone.  I'd guess the one you drew is Gnd.  The screen shot shows a board I made that has GndA - you could use that.  It doesn't connect to Gnd.





LoveLaika:
I did do that. My board has a large copper pour tied to GND as the net. I then made another copper pour to fit over that GND pour and tied it to the net as indicated by the exposed pad, but it never showed.

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