Having a full regulator on VCCPLL causes the ESD network in the ICE40 to
freak out, dumping VCCPLL into GND and trying very hard to burn out the
regulator.
Replace it with a simple RC filter network, which is less clean but
results in a happier ESD network.
Signed-off-by: Sean Cross <sean@xobs.io>
Redo the xtal footprint, which was just flat out wrong.
Also, replace the +5V TVS diode with one that can handle more than 5V,
so it's not always shorting out.
Signed-off-by: Sean Cross <sean@xobs.io>
Increase the size of the keepout area in order to remove some extra
copper that was appearing around one of the ground pads.
Signed-off-by: Sean Cross <sean@xobs.io>
This is an initial commit removing the excess capacitors.
We will eventually add ESD protection ICs in the space that has been
freed up.
Signed-off-by: Sean Cross <sean@xobs.io>
Reduce the ground fill under the IC, to prevent it from sliding around.
This gives less copper, but it should be fine for the currents we're
drawing.
Loosen up the routing of the 5V plane, which involves moving some
components around. This increases the amount of copper that goes to the
various regulators.
Finally, reorder the caps so that the larger ones are further from the
IC. This is done because they have a slower response time, and so can
be further away.
Signed-off-by: Sean Cross <sean@xobs.io>
Move some vias around to get the 5V plane more breathing room. Add a
small pour to give more copper and stabilize the net.
Signed-off-by: Sean Cross <sean@xobs.io>
Add more 5V vias near the 1.2V regulator, and replace a manual trace
with a copper pour. This will increase the amount of copper going to
both the 3.3V and 1.2V regulators, which should improve stability.
While we're at it, remove an errant silk artifact on the USB connector.
Signed-off-by: Sean Cross <sean@xobs.io>
Add a note indicating the PCB thickness and color.
Also, move the drill origin to the lower-left corner, to aid in machine
assembly.
Signed-off-by: Sean Cross <sean@xobs.io>
Add more silk, indicating website and other info.
While we're at it, move some traces around to give more copper area, and
drop some more vias to improve ground performance.
Signed-off-by: Sean Cross <sean@xobs.io>
