On Fri, Sep 11, 2009 at 04:10:41AM -0300, Werner Almesberger wrote: > I'll feel much better about having the switch if it cuts all supplies > and not leave the modem in a probably completely undesigned-for > configuration.
Me too. > We could try the following approach: > > - bring back the switch (probably best to switch to the NTGD1100L > while we're at it) and a pull-up > > - route both VBATT and VBATT_PA through the switch > > - add a 0R resistor parallel to the switch. Put it somewhere where > it can be reworked. Since we feel confident, we make it NC for SMT. > > - we then need to free one of the PMU's GPIOs. MODEM_nON might be > the best choice, since the switch would override it anyway. > > - put a 0R into MODEM_nON from the CPU so that, in case of trouble, > we can fall back to the current configuration > > Does that sound good ? I was thinking of just connecting the switch in parallel with R8101 (currently 0R that we would make NC) and connecting the enable input (ON/OFF) to the GSM_2V8 supply. But I have not checked the power sequencing requirements of the GE865. Right now I'm also confused by the lack of a connection from the GSM_2V8 supply to the modem. Does it have an internal 2.8 V LDO to derive the I/O voltage from the 3.8 V supply? -- Rask Ingemann Lambertsen Danish law requires addresses in e-mail to be logged and stored for a year _______________________________________________ gta02-core mailing list [email protected] https://lists.openmoko.org/mailman/listinfo/gta02-core
