Behaviors of loop-gain functions and other control transfer functions are critically important in the design of current-mode DC/DC converters. In this paper, procedures were proposed to use SIMPLIS to simulate the two loop gain functions T1 and T2, the equivalent control plant transfer function when the inner loop is closed Fin, current loop gain Ti and voltage loop gain Tv. These models are practical to obtain, simple to use, accurate beyond switching frequency and are easily amendable to incorporate new converter configurations and new control schemes