I want to integrate an AirPrime SL6087 GSM modem into a design, this is my first try at working with a GSM module. The datasheet states that the modem draws 2A for 1mS every 4mS (max) at 3.6V, the problem is that I intend to run this project from a single Li-Po battery and want to use a buck-boost regulator so I can keep the unit alive for as long as possible (running it down all the way to 3V). The only regulator I can find capable of this is the LTC3113 but there doesn't seem to be stock anywhere. The LTC3112 is also a possibility but it's 2.5A output current is rated at 5V input not down to 3V.
My question is this, there's a lot of small GSM products on the market, how do these go about keeping the power supply stable while running on a single Li-Po battery? I have this nagging feeling that I'm over complicating this...
The complete datasheet for the module is only available after logging in, registration is free however. Here's a quick recap (page 20):
In connected mode, the RF Power Amplifier current (2.0A peak in GSM/GPRS mode) flows with a ratio of 2/8 of the time (around 1154uS every 4.615mS)