I made a sim900 board with the power schematic in the sim900 document (5V to 4.1V). For Sim908: Just curious if anyone has made a power schematic (or powered the board directly) with 3.3V? The spec says it is okay for GPS/GPRS, but curious if anyone has done it?
Also 4.1V was too much voltage for sleep mode, is 3.3V okay? Does anyone know what the expected voltage is? Not mentioned in the documents....
I have heard I can power directly from a Battery (I assume with decoupling capacitors), is that true (even with the 2A Peak requirement)? Has someone successfully done it? How close does the battery need to be?
Datasheet says 3.2 to 4.8.... Not sure if 3.3 is too close though.
I made a sim900 board already successfully with 4.1V to the sim900 but it says that the voltage is too high during sleep mode. Curious how low it must be for sleep mode sim900/sim908.