[gta02-core] SD/SIM vs. ESD and EMI

Werner Almesberger werner at openmoko.org
Mon Nov 30 17:45:26 CET 2009

There's one more area where the design is not protected against ESD,
the SD/SIM connector.

Against EMI, we have RC filters on the SDIO side and C with implied
R on the SIM side.

Now, the lack of ESD protection doesn't seem to have caused problems
in GTA02, so I'd be reluctant to open another construction site to
add ESD protection there.

However, I'd like to have a plan B that could be implemented in case
of trouble (but only then). That would be to replace the small
capacitors (C7501-7510) with TVSs, which also have a small

Does this sound reasonable ?

- Werner

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