In a switched mode power converter, the conduction time of the power switch is regulated according to the input and output voltages. Thus, a power converter is a self-contained control system in which the conduction time is modulated in reaction to changes in the input and output voltages. From a theoretical approach, control loop design often involves complicated equations, making control a challenging but often misunderstood area in switched mode power supply design. A simplified approach to feedback control loop analysis is presented in the following pages, beginning with a general overview of various parameters affecting performance in a switching power system. A demonstration of an actual power supply is given to show the components involved in designing the characteristics of the control loop. Test results and measurement techniques are also included