In this paper, we propose a new model of skin effect in time domain to perform mixed simulations using VHDL-AMS. It is used for RF interconnects but can be implemented in other applications. The skin effect is described by the resistances behavior as a function of square root of the frequency. We use the Laplace domain to have an access to the frequency in a time domain simulation, and to approximate the square root of the frequency into a ratio of two polynomial functions. We use an algorithm searching to minimize the maximum error. Then, we compare the results of a time domain simulation of voltage attenuation with those of frequency domain ones. The model has been validated on a wide frequency range.