Abstract: The control of power electronic circuits is a challenging field of research due to the requirements imposed by the applications. A controller design for a Buck converter which steps down a given dc value to a desired regulated dc value is the system taken into consideration in this study. The controller designed for Buck converter has to control rise time, peak overshoot, settling time, bandwidth which are affected by the load and line variations. Quarter Amplitude Decay (QAD), Internal Model Control (IMC) and Pole placement techniques are used to obtain the parameters of the PID controller. The performances of these tuning procedures are evaluated and the comparison is tabulated. It is found that the controller tuned by pole placement method gives less rise time and settling time with negligible overshoot. But transfer function of pole-placement base controller is quite complex and has high number coefficients which is difficult to realize in real time systems. QAD based PID controller has less rise time and settling time but it has peak over shoot which will produce voltage spikes in real time systems. Hence an IMC based PID controller which has acceptable rise time and settling time with no peak overshoot is realized in real form by using operational amplifiers. The performance is evaluated and tabulated under varying load and reference voltage conditions.