The LTC3440 synchronous buck-boost converter that provides an optimal solution for GSM modems and USB OTG devices is described.
Synchronous buck-boost controller
GSM modems have become popular as a wireless data transfer solution; however, they frequently require large bursts of current that exceed the maximum input current available to the voltage regulator. Many can be powered from a USB port (4.5V to 5.5V input) or a PCMCIA port (3V to 3.6V input), where 3.xV is required to supply the RF power amplifier that draws current pulses up to 2A. Since the input from the USB or PCMCIA port ...