Switched mode DC-DC converters are electronic circuits which convert a voltage from one level to a higher or lower one. They are considered to be the most advantageous supply tools for feeding some electronic systems in comparison with linear power supplies which are simple and have a low cost. However, they are inefficient as they convert the dropped voltage into heat dissipation. The switched-mode DC-DC converters are more and more used in some electronic devices such as DC-drive systems, electric traction, electric vehicles, machine tools, distributed power supply systems and embedded systems to extend battery life by minimizing power consumption (Rashid, 2001). There are several topologies of DC-DC converters which can be classified into non-isolated and isolated topologies. The principle non-isolated structures of the DC-DC converters are the Buck, the Buck Boost, the Boost and the Cuk converters. The isolated topologies are used in applications where isolation is necessary between the input and the load. The isolation is insured by the use of an isolating transformer. The DC-DC converters are designed to work in open-loop mode. However, these kinds of converters are nonlinear. This nonlinearity is due to the switch and the converter component characteristics. For some applications, the DC-DC converters must provide a regulated output voltage with low ripple rate. In addition, the converter must be robust against load or input voltage variations and converter parametric uncertainties. Thus, for such case the regulation of the output voltage must be performed in a closed loop control mode. Proportional Integral and hysteretic control are the most used closed loop control solutions of DC-DC converters. This can be explained by the fact that these control techniques are not complicated and can be easily implemented on electronic circuit devises. Nowadays, the control systems such as microcontrollers and programmable logic devises are sophisticated and allow the implementation of complex and time consuming control techniques. The control theory provides several control solutions which can be classified into conventional and non-conventional controls. Many conventional controls, such as the PID control, were applied to DC-DC converters. The design of the linear controller is based on the linearized converter model around an equilibrium point near which the controller gives