[gta02-core] Modem schematic / RF help needed

Dave Ball openmoko at underhand.org
Mon Sep 14 00:46:51 CEST 2009

Werner Almesberger wrote:
> I think we can save several test points, since they also exist on the CPU side. 

Doh! Removed the duplication.

> Then, I think we should name test points consistently, i.e., TP*
> instead of P*.


> Regarding the 33 Ohm series resistors, do they really have to be so
> low ? They should be large enough to reliably protect the modem if
> the CPU accidently switches one of those inputs to output, so I'd
> be much more comfortable with something in the order of 1 kOhm.

Yup, 33R does seem a little low!  Updated to 1k.

> I think we should also add a remark that these series resistors
> should be placed close to the CPU, to keep most of the traces close
> to the low-impedance end (the modem's outputs).

Added a note to this effect.


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