The buck converter is a very common switched mode DC-DC converter. This converter is designed to reduce an input voltage supply to a lower output voltage. The generation of a voltage higher than the input voltage requires other converter topologies such as the boost converter. However, with a minor modification, the buck converter can simultaneously provide both a lower and a high output voltage. In this paper we derive a model of such a modified buck converter. It is also shown how these voltages can be adjusted largely independently of each other by suitable control of the converter.