The L3380 is PWM step up DC-DC switching controller that operates from 0.9V. The low start up input voltage makes L3380 specially designed for powering portable equipment from one or two cells battery packs. This device consist of a soft start circuit, a reference voltage source, an error amplifier, an oscillator, a phase compensation, a PWM controller and an output drive circuit for driving external power transistor. Additionally, a chip enable feature is provided to power down the converter for extended battery life. The device features a voltage mode PWM control loop, providing stable and high efficiency operation over a broad load current range.