Working on my first battery powered device. I need some help keeping power usage to very low levels. Here is the situation. The board has three devices on it:
GSM Cell modem (3.4 - 4.0v) 4.0 is recommended
uC (3.0 - 3.6v range) 100mA
Xbee radio (3.0 - 3.6v range) 300mA
Max load with all devices = 1 amp (unsure about GSM modem)
Can I power everything on this board by just hooking it up to a li-ion 1500mAh battery? I'm worried that the voltage may not always be between all the ranges for the devices. Right now I am thinking of using two regulators. 1 reg will power the Uc and xbee (3.3v) and another will power just the cell modem (4.0v).
Obviously I want regs with a very low quiescent current drain. Less than 1mA would be nice. Any other ideas? The cell modem wanting 4.0 volts kinda throws a wrench in things. Also, the datasheet is very unclear about how much current it takes.