Various embodiments of the invention provide for single and dual phase charge pump, two stage DC/DC buck-boost converters having fast line and load transient control irrespective of load conditions. In certain embodiments of the invention, this is accomplished by controlling a desired output voltage with an error amplifier that controls a plurality of hysteresis comparators. A dual phase charge pump architecture eliminates ripple currents and mode transitions and increases efficiency by splitting the total current between two paths. Certain embodiments allow to use low voltage semiconductor devices, which significantly reduces switching losses and further increases efficiency.