Werner, > Regarding component choices, I looked for filter arrays which would > save even more space, e.g., Murata's NFA series. Alas, they all > seem to be difficult to source.
How do you determine that? Wolfgang On Thu, Oct 08, 2009 at 11:09:32AM -0300, Werner Almesberger wrote: > Rene Harder wrote: > > Yes [ R4401 ] looks pretty much like a current limiter. > > Joerg and I had a quick discussion on IRC: > > - he agrees that R4401 is probably a current limiter to protect the > codec's MIC1 input. Can't hurt to have it. > > - he also agrees that C4405 should go. Also, R4404 can safely meet > the same fate. > > - he suggests to switch to a symmetrical configuration for the > microphone, like in earlier GTA02 variants or in GTA01. > > The change to single-ended in GTA02v6 was an unsuccessful attempt > to solve the buzz problem. A symmetrical design would have the > advantage of better common-mode rejection. > > In the symmetrical design, R4301 and R4302 would be useless, so > it's not any more complicated than the asymmetrical design. Plus, > it would actually be a bit clearer what things do. > > Regarding component choices, I looked for filter arrays which would > save even more space, e.g., Murata's NFA series. Alas, they all > seem to be difficult to source. > > - Werner > > _______________________________________________ > gta02-core mailing list > [email protected] > https://lists.openmoko.org/mailman/listinfo/gta02-core _______________________________________________ gta02-core mailing list [email protected] https://lists.openmoko.org/mailman/listinfo/gta02-core
