Quote:
Originally Posted by PeteAU
Hi,
Please somebody check it for obvious errors. Any 2nd pair of eyes is welcome.
Done! But wait until somebody checks this revision, there might be errors.
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This project is getting nicer and nicer (and popular it seems
)
I had a look at the PCB layout again and I am wondering if we can improve the decoupling. Maybe this can improve the performance with difficult RAM chips as experienced by MQ666. The ground planes on the main board are intersected on a lot of places by long traces. Ideally the loop formed by the VCC and GND wires of the RAM chips and the decoupling capacitor is as small as possible.
For example; the ground pins of C1, C4 and C7 are not directly connected to the gnd pins of the RAM chips they decouple. In their case it is only a matter of adding some stitching via's to the bottom layer or swapping them so that the VCC trace is on the other side. Same goes for C8, swapping C8 by 180 degrees would make the ground terminal connect directly to the ground terminal of RAM chip U3.