Hello members,
I am working on PIC 16f684 which uses interrupt on change. On receiving interrupt on port A, I am resetting a particular port pin,which is otherwise logic high. This logic works fine with through hole components, but the same logic does not work when the circuit is implemented in SMD. I even added ESD (electrostatic discharge) protection to no avail. ESD includes two zener diodes connected back to back between Vss & Vdd and the output given to interrupt on change pin.
Some discussion on this will be great help.
Thank-you.

 

The silicon inside the package is the same no matter if it is a thru hole or a SMD device, so I doubt changing to SMD caused the fail. Far more likely the build is slightly different (not same schematic 100%) or the circuit only seemed to work.

Posting the schematic & code would help us see. Hopefully this is a learning ap and not a full blown project. ;-)

And welcome to the forums!

 

I agree with Ernie. It's far more likely that the difference is in the layout, or the software you've put into the chip--even if you think it isn't.

Way less likely is the possibility that the surface mount chip has suffered some kind of damage that lets it continue running, but not running right. Or actually, have you verified that the chip is alive? Have you loaded the code to it?