Hi. So im working on a project that will use a GSM module. and the SARA G3 from UBLOX cought my eyes since it so small. But after reading the dataheet it says recommended voltage is 3.8v, min is 3.25v and max 4.5v. they also say "The input voltage at all the VCC must be above the normal operating range minimum limit to switch-on the module. Module is still fully
functional when the input voltage at the VCC pins drops below the herein stated normal operating range minimum limit, but RF
performance may be affected."
Does this mean it needs atleast 3.25v to start or 3.8v to start?
Yes, it needs 3.25V to start. The 'normal operating range' is stated to be 3.35V to 4.50. It may shut down if the voltage drops to 2.8 or 3.0V, depending on the power input pin and the model of the device.
Great! So a 3.6v lipo battery should be enough to power this thing?
It should work fine, as long as the battery itself can handle the load. I would also use short runs of decent gauge wire between the battery and the transmitter to minimize the voltage drops.
Please remember that when (most) lithium batteries reach 3.0V on the cell, there is almost no power left in them, and that draining them much below 3.0V risks permanent damage to the cell.
More like guarantees permanent damage?
Anyway reading those specs its almost as if the unit was designed to work from a mobile
phone battery isn't it? 8)
But this should not be a probelm if the battery has built-in protection against overload, short circuit and under voltage?
digestivekex:
But this should not be a probelm if the battery has built-in protection against overload, short circuit and under voltage?
I'm saying the GSM module knows not to take the battery below 3.25V, and for very good reason.