Ben Thompson <[email protected]> wrote: > Here is my attempt :- > http://wiki.openmoko.org/wiki/Image:Gta02a6_comms_chips_under_shield.JPG
This photo is pretty good - thanks! From it we can tell that: * The RF transceiver chip is TRF6151C, just like the one on the Leonardo board for which we have the docs. It's a *quad-band* GSM RF transceiver chip, although it isn't obvious from the pinout: it has 3 differential-pair RF inputs, but one of them (the one called GSM in the datasheet) handles both 900 and 850 MHz Rx. (1800 MHz Rx is on the DCS input pair and 1900 MHz Rx is on the PCS one.) The RF outputs going to the PA are single-ended and combined: one for the low bands, one for the high bands. * The RF PA (power amplifier) is the classic RF3166, once again the same as what one would find in a "vanilla" Calypso phone. The Leonardo board schematics feature AWT6108, but also say: "Second source option is RF3133 from RF Micro Devices that can be used on same footprint". * The shiny block component (corresponding to U401 in Om's "component placement" PDF doc) must be the antenna switch. One can also see 3 little components next to it, corresponding to U402 through U404. I reason that these must be the SAW filters for the 3 bands supported by each GTA02 version. It's too bad that Om-Inc chose not to use a part like M034F instead (an antenna switch version with the SAW filters built in), as that would have made it a quad-band phone: all other components are already quad-band-ready. I wonder if the only difference between the 850/1800/1900 MHz and 900/1800/1900 MHz versions of the GTA02 is in that one SAW filter part that sits between the low-band output pins of the antenna switch and the low-band input pins of the TRF6151C. (What makes me think so? See how real quad-band phones based on the same Calypso chipset handle it: Leonardo_plus_quadband_schem.pdf and the M034F.pdf in my PDF Calypso doc collection.) Makes me wonder if a GTA02 can be changed from one version to the other by carefully replacing that one part and changing the Calypso FW image accordingly... Now we need to figure out what the RF block looks like in the TSM30: that would tell us whether or not the RF chip control code is something we would need to be concerned with when porting the TSM30 source to the GTA02. What we *really* need are TSM30 schematics. Schematics used to be included in phone service manuals, but I don't know how to search for a service manual in Spanish... MS _______________________________________________ Openmoko community mailing list [email protected] http://lists.openmoko.org/mailman/listinfo/community
