Dynamic thermal management (DTM) schemes rely on physical sensors to provide them with feedback to ensure an accurate and closed-loop throttling mechanism. Power-density trends in current-generation, high-performance processors motivate the need for multiple low-area, low-power and high-sensitivity temperature monitoring circuits. To this end, we have proposed and implemented in 45nm CMOS, a novel, digital, on-chip thermal sensing circuit with a high thermal sensitivity of 4.56mV/ºC, low power dissipation of 133.4μW and a compact layout occupying 12.4μ2. The design is robust towards process and supply induced noise incurring a 1-σ accuracy loss of <=1.24ºC for a +/-10% random variation in the physical and environmental parameters.