Thermal balancing and reducing hot-spots are two important challenges facing the MPSoC designers. In this work, we model the thermal behavior of a MPSoC as a control theory problem which enables the design of an optimum frequency controller without depending on the thermal profile of the chip. The optimization performed by the controller is targeted to achieve thermal balancing on the MPSoC thermal profile to avoid hotspots and improve its reliability. The proposed system is able to perform an on-line minimization of chip thermal gradients based on both scheduler requirements and the chip thermal profile. We compare this with state of the art thermal management approaches. Our comparison shows that the proposed system offers a better both thermal profile (temperature differences higher than 4 degrees C have been reduced from 27.9% to 0.45%) and performance (up to 32% task waiting time reduction).