In this paper, we present the design and implementation of three types of integrated temperature sensors in 0.18-$\\mu$m SOI XFAB process. The presented sensors are used to monitor the thermal activities of an integrated system-on-chip (SoC)-based DC-DC converter. Both conduction and switching losses in the integrated high-power half-bridge devices generate a considerable amount of heat. A ring oscillator, voltage threshold, and diode potential-based temperature sensors were implemented. Simulation results show the proper functionality of the implemented circuits. The performance of the ring oscillator-based sensor is modeled to mitigate the impact of process variations on the measured temperatures.