The nonlinear modeling and analysis of dc-dc converters in the continuous mode and discontinuous mode has been done by averaging and discrete-sampling techniques. The averaging technique is simple to use and averages the output voltage. The discrete technique is very complex and cumbersome, but accurately predicts the envelope of the output voltage. A new model is developed by combining the aforementioned techniques. This new model, the discrete-average model, accurately predicts the envelope of the output voltage and is easy to implement in circuit and state variable forms. The major points of this dissertation are as follows: 1. The proposed model is shown to be dependent on the type of duty cycle control. 2. The proper selection of the power stage model, between average and discrete-average, is largely a function of the error processor in the feedback loop. 3. The accuracy of the measurement data taken by a conventional technique is affected by the conditions at which the data is collected. / Ph. D.