We are presenting a new approach for mapping a continuous time controller to a discrete time controller. Methods traditionally used for this mapping include forward rectangular rule, bilinear rule and zero-pole matching. This approach, unlike these other methods, produces a discrete time transfer function with a magnitude response exactly same as its analog prototype. To achieve this objective we are using the Magnitude Invariance Method (MIM) which was recently developed in the field of signal processing. The step and frequency responses of the closed loop systems obtained using this approach will be systematically investigated to evaluate the effectiveness of this mapping.