A DC-DC converter having low power consumption by reducing an input current and an organic light emitting display using the same. In one embodiment, a DC-DC converter includes a buck-boost circuit for generating and outputting a second power of a second power source by receiving an input voltage. The buck-boost circuit adjusts and outputs the voltage level of the second power of the second power source in response to the voltage level of the input voltage. A controller controls the buck-boost circuit. The buck-boost circuit includes a first coil coupled between a first node and a ground; a first capacitor having first and second electrodes, the first electrode being coupled to the first node, a first switch coupled between the first node and an input terminal; and a second switch coupled between the second electrode of the capacitor and ground.