Hi all,
So after building my first core module in record time ( ;)) I was wondering about the bypass capacitors.
According to http://ucapps.de/mbhp_core.html:
C7, C8 100nF The additional bypass caps have to be placed on the bottom side of the PCB, as close to the power pins of the PIC as possible.
…but in all the photos on the same page the caps are on the top side of the PCB.
I did a quick search on the forum for “bypass”, but didn’t find anything obvious. Is the cap placement important?
Nope, it’s not. What’s important is that they are placed closely to the PIC pins. If I’m not mistaken, the information on the site you linked is meant as a pointer for people upgrading core-PCBs which do not have the footprints for the bypass caps yet.
What’s important is that they are placed closely to the PIC pins.
Like nILS writes but a bit more precise for understanding what it does: Only the Vdd side must be as close to the pin as possible, since it’s intended to take out spikes or ripple out of the supply line just before the IC connection.
Greets, Roger
Cheers for the replies and explanation. Ok, so I’ll just leave them where they are then…