This work presents a modular architecture based on the input series output parallel (ISOP) connection of Full Bridge Phase Shifted power converters with a common input filter. The modeling of the converter architecture taking into account the effect of the common input filter is the previous step to the controller design in order to ensure a proper regulation of external converter quantities, such as output voltage, and internal quantities, such as input voltages. In this paper a small signal model of an ISOP Full Bridge Phase Shifted converter taking into consideration the input filter is developed. Simulation and experimental results validate the theoretical predictions