JEE_V7_N2_RP5 Shailaja Rout Pradosh Ranjan Parida Dr. Chinmoy Kumar Panigrahi Dr. M. Basu Journal on Electrical Engineering 2230 – 7176 7 2 34 37 DC-DC Converters, State Space Averaging(SSA), Enhanced State Space Averaging(ESSA), Digital Control, Variable Switching Frequency Operation, PID Controller, Digital Pulse Width Modulation(DPWM) In this work the authors propose a novel approach in modelling and controller design of the synchronous dc-dc step down converters. Power electronic converters are mainly periodic variable systems due to their variable switched systems. The generalized or enhanced the state space averaging is a better approach than the state space averaging as it defines them by a unified set of differential equations, capable of representing circuit waveforms. This model is then used to design a PID controller which will help us in understanding the converter dynamics. October - December 2013 Copyright © 2013 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=2552